Fruit for the Month: June

Blueberries.
Photo Marilyn Rayne Squier

This is another post in my new monthly series, about small fruits that can be grown sustainably in a mid-Atlantic climate. I’ll talk about planting, pruning, harvesting and care of the plants, according to the season. I’ll give links to useful publications. I’ll have a focus fruit, and then more about others that need attention during the month. We do grow apples and pears, and some other tree fruit, but I’m not writing about those as I don’t have much recent experience.

Blueberries are the focus fruit for June

June is the month in our climate, to harvest blueberries. Blueberries are a great crop to grow, as they are not troubled by many pests or diseases (apart from birds). While you are harvesting take notes (or photos) of the various varieties you have, and when and how well they are producing, so that you will know which ones to propagate from in the winter, if you want more.

See my article about blueberries in Growing for Market magazine

See ATTRA Blueberries: Organic Production available free online, for a wealth of information from choosing varieties, planting, details on pests and diseases you might encounter. Updated 2022. Also search the ATTRA site for other info on blueberries, such as soil management (blueberries need acid soil), living clover mulches, and honeybees and alternative pollinators.

Harvesting blueberries

Blueberry harvest. Note “berry bucket” hanging around the worker’s neck. Photo Marilyn Rayne Squier

I recommend harvesting two days a week, in the mornings, once the dew has dried, to avoid spreading fungal diseases. Blueberries don’t deteriorate or over-ripen as quickly as softer fruit, so if you can only find time once a week, that will be OK. Or if you are selling blueberries, once a week may work better for your sales. Blueberries don’t crush as easily as strawberries or raspberries, so if you have lots you can put them in buckets or crates. We usually harvest into homemade berry buckets with long rope handles, that we can hang around our necks, freeing up both hands for picking berries. Our berry buckets are made by cutting plastic gallon jugs and adding rope through holes we punch near the top. Full berry buckets get emptied into a bigger bucket.

Only pick the berries that are purple-black all over. Check the back of each each ripe-looking blueberry to make sure it’s ripe all over. The area around the stem is the last to change color. Really ripe blueberries will “tickle” from the bush into your hand

Do not wash fruit before refrigerating, as this leads to rot.

Types of blueberries

We grow Northern Highbush blueberries here in winter-hardiness zone 7a (suitable for zones 3-7) and we like to have a crop we can harvest standing up!  There are also lowbush blueberries, which are popular in cooler climates, such as Maine. Rabbiteye varieties are better to the South, in the region roughly south of Interstate 40 (mostly zones 6-9). Rabbiteyes are taller plants, with smaller berries than highbush types. A new hybrid type, Southern highbush, is adapted to the southern rabbiteye zone and the coastal South (zones 6-10). Look into these if you are in the right area: they have a lower chilling-hours requirement, and flower and fruit earlier than highbush or rabbiteye varieties. As the climate changes, fruit growers are challenged by traditional crops no longer getting enough winter chilling hours to fruit. (Chilling is the number of accumulated hours at temperatures below 45°F/7°C in the dormant season.) Balance this with your changing frost dates, as earlier flowering will not be an advantage if your last frost is going to cancel the fruit. Remember that all blueberries are self-fertile but will produce better crops if you plant several compatible cross-pollinating varieties.

Young Blue Crop northern highbush blueberry.
Photo Kathryn Simmons

At our farm, Duke has been a very reliable early fruiting highbush variety, whereas Spartan has not worked out. We like to have several varieties with different ripening dates, to extend the harvest. Blue Crop, Blue Jay, Elliott and Chandler also do well here. If I was starting over, I’d also try some Southern Highbush varieties.

We have bought good plants from Finch Blueberry Nursery in Bailey, North Carolina, as well as from a more local source in SW Virginia (now retired). If you only want a few plants, buy potted blueberry plants locally. Otherwise, order bareroot plants shipped to you. In Virginia Edible Landscaping offers a wide choice.

When to plant blueberries

If you are planning to plant blueberries, here are some considerations. Generally you will want o buy young bushes and plant them in the dormant season. In warm areas, plant in late fall so the plants get roots established before your early spring thrusts them into opening buds. In cooler zones, plant in early spring, so that winter does not kill them.

New blueberry plant with winter wire mesh protection. Photo Kathryn Simmons

As with all perennials, clear the area of perennial weeds the previous year, and reduce annual weeds, for instance by growing a good cover crop, which will smother emerging annual weeds and also feed the soil. Get a soil test, and follow the recommendations to amend the pH to 4.8-5.5 using sulfur in spring or fall before planting. I like the pelleted sulfur, that looks like lentils, because it is easy to spread, and no dust gets in your lungs. Depending on your soil type, you might need 430-1750 pounds of S per acre, or 1-4 pounds per 100 sq ft. Work in some good compost before planting.

Plan space between the rows that will let you walk, mow or whatever you need to do even once the bushes have reached full size. 8-12ft is recommended. Ours are a bit closer than that. In the row you can either plan for a hedge effect, or leave yourself access space. You can plant blueberries on raised beds or wide ridges. You can move bushes later in life, if you find they are competing too much.

Blueberries six years after planting. Photo Kathryn Simmons

Plan how you will cover the soil. I recommend landscape fabric topped by bark mulch or woodchips. This combination works well to keep perennial weeds at bay (wiregrass!). If you are avoiding plastic, you can use double layers of overlapping cardboard topped by 3” of organic mulch: chips, sawdust, straw or spoiled hay. Blueberries don’t do well with plastic mulch that is impervious to water, as it encourages the roots to grow just under the plastic, where they can easily get overheated and die. Some people like to grow a living mulch, perhaps mowing it to mulch closer around the plants once it dries. A hybrid model has mulch in the rows and a cover crop between the rows.

Blueberries have shallow roots, so you will likely need some irrigation method. I like drip irrigation, but overhead sprinklers work too.

You will, of course, have some annual care to provide. Each spring, expect to provide some source of nitrogen and potassium, as needed.  I’ll cover that another time. Each winter, prune for strong branches and good levels of production, and remove any perennial weeds.

Blueberries showing Tenax fencing and basket balls on posts to support roof netting. Photo Kathryn Simmons

Pests to watch out for include big ones like deer, groundhogs, birds and uninvited humans. We have a triple fence, with wire netting in the ground against burrowing animals, 7’ tall Tenax deer fencing, and seasonally, Avigard flexible bird netting over the top. For our newer blueberry planting we make a temporary hooped structure and cover just with the bird netting, held down to the ground with 6” soil staples. This planting is nearer our buildings than the older one, and is not visited by deer or groundhogs.

Blueberry netting on PVC electrical conduit hoops. Photo Pam Dawling

Smaller pests include blueberry maggots, blueberry stem borers, cranberry fruitworms, cherry fruitworms, Japanese beetles, leafrollers, leafhoppers, and aphids. Our perhaps, like us, you will not be troubled by any of these.

Diseases include mummy berry, Botrytis grey mold, Anthracnose, stem blight, stem canker, rust, phytopthora root rot, Phomopsis twig blight, blueberry stunt and several viruses. A Cornell University blueberry diagnostic tool offers a step-by-step exercise to help figure out what diseases may be affecting your crop.

Propagate blueberries by layering a low branch, as you see here with Chandler variety. Photo Kathryn Simmons

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Other small fruits available in June

Two rows of floricane raspberries with a willow and grapes in the background. Photo Kathryn Simmons

Cherries, red raspberries, strawberries, Juneberries, gooseberries  mulberries. Blackberries, apricots, peaches, plums.

If you live in Virginia or nearby, see this produce calendar

Other fruit care in June

New grape vine in May. Photo Bridget Aleshire

Grapes: Mow, weed, water in drought. If you have young vines, remove side branches from the trunks, and fruitlets. Your goal is to first grow strong plants, then produce grapes after that.

Strawberries: Prepare for new strawberries in early June: Disk or till the area for new strawberries if using bare-root plants, and prepare the beds with compost, driptape, and landscape fabric.

June 16-July 16: If using bare-root transplants, plant new strawberry beds.

Late June/early July (after fruiting): Dismantle two-year-old beds. Renovate carry-over strawberries by mowing or shearing/clipping weed and mulch, but don’t compost them. . Plant new strawberries if using bare-root transplants, perhaps rooted runners in the paths of older beds.

Rainbow and Kathryn spread hay over the new strawberry bed. Photo Luke Stovall

All fruit: Water all fruit crops. Weed, mow aisles as needed. Weed and mulch rhubarb, lop flowers. Record condition and fruiting dates of new grapes, blueberries. Note best varieties.

Which Vegetables are Genetically Modified (GMOs)?

Our first sweet corn of the season. Bodacious. Early July. Not GMO
Photo Pam Dawling

Recently we were given a gift of sweet corn from somewhere warmer than central Virginia. It wasn’t Organic, so I wondered if it was genetically modified. I try to avoid eating GMOs, because I don’t support the practice of inserting bits of other organisms in existing crops. Corn varieties often have Bacillus thuriengensis (Bt) inserted in their DNA with the goal of killing caterpillars that eat corn kernels.

USDA Organic symbol

Anything certified USDA Organic is not allowed to have any GMOs in it, so that’s one way to avoid getting GMOs. Growing your own food is a certain way to avoid GMOs, if you don’t buy GMO varieties or suffer cross-pollination from GMO crops.

Non-GMO Project symbol

The Non-GMO Project is the U.S. organization that provides testing and labeling for absence or presence of GMO in products. The “Non-GMO Project Seal” certifies that the product contains 0.9% or less GMO ingredients.

I’m going to skip ahead to talking about which vegetable crops are available in genetically modified varieties, because there are not many, and I’m not interested in worrying people! Then I’ll go into details.

The Big Three GMO Crops in the US

Edamame soy beans (soy for fresh eating). Not GMO.
Photo Raddysh Acorn

Soy, canola and corn are the three food crops in the US that are most likely to be genetically modified. Starting with corn (maize): 92% of all corn grown in the US is GMO. Of corn grown, only 1% is sweet corn. Of sweet corn grown in 2018, 10% is GMO. When you see a field of corn, it is almost certainly GMO, unless you are looking at an Organic farm.

What is field corn? “Corn (such as dent corn or flint corn) with starchy kernels that are used especially as livestock feed or processed into food products (such as cornmeal, corn oil, and corn syrup) or ethanol,” (Merriam Webster). Of the field corn in the US, 40% goes to make ethanol for vehicle fuels, 40% goes to livestock feed, and 20% goes into processed foods for humans.

In 2000, GM StarLink corn was recalled, when over 300 different food products were found to contain a genetically modified corn that had not been approved for human consumption (only animal feed). It was the first recall of a genetically modified food.

What about wheat? Farmers have shown a distinct preference for not growing GMO wheat. This is because much of the wheat grown in the US is for export, and people in many other countries refuse to eat GMOs.

Which Other Vegetables Might be GM?

Here is a 2013 article published in the Journal of Food Science and Technology. “Genetically modified foods: safety, risks and public concerns—a review” by A. S. Bawa and K. R. Anilakumar

There are only a few vegetables that have any GMO varieties. Some have been tried and failed. All vegetable seed is non-GMO unless labeled, and when purchasing GMO seed, you have to sign waivers. When searching on line, try various labels: genetically modified, GM, genetically engineered, GE, transgenic.

Gentry yellow squash in our hoophouse in late May. Not GMO
Photo Pam Dawling

Summer Squash and Zucchini

To avoid zucchini yellow mosaic virus and watermelon mottle virus in summer squash and zucchini, GM varieties were created, starting in 1995. When I researched GM squash varieties in July 2017 for an article I wrote, I found mention of ten summer squash and zucchini, but now there seem to be fewer. On the Bayer/Seminis website for their squash varieties, in 2017, these all helpfully had a “B” icon (Biotech). The names sound like B-movies: Conqueror III, Destiny III, Liberator III, Patriot II, Prelude II, XPT1832 III yellow squash and Judgement III, Justice III, SV0474YG, SV6009YG zucchini. The website has been updated, as have the variety offerings, and they are less prominently labeled. ZW-20 virus-resistant yellow crookneck squash is a current transgenic line.

In 2005, about 13% of the zucchini grown in the USA was genetically modified to resist three viruses; the zucchini is also grown in Canada (Johnson 2008).

Mexican researchers in 2004 wrote a paper Assessing the risk of releasing transgenic Cucurbita spp. in Mexico. Localities with native wild relatives of transgenic squash were at risk of the greatest trouble from cross pollination. The genetic legacy of ancient squash lineages was at risk. Gene flow between crops and their wild relatives was widely documented. The authors urged much caution about where and when GMO squash should be permitted.

GM squash also poses a risk that its virus genes or the proteins they produce could interact with other viruses to produce new diseases. And, as with any genetically engineered crop, the squash poses the risk that its new genes might cause it to spread and become difficult to control.

Sugar Beets

The USA extracts 90 % of its sugar “needs” from US-grown sugar beet and sugarcane. Of the domestically grown sugar, half comes from sugar beet, and half from sugarcane. After deregulation in 2005, sugar beet resistant to glyphosate (RoundUp) was extensively adopted in the USA. 95% of sugar beets grown in the US are GM. The sugar produced from GM sugar beets is highly refined and contains no DNA or protein—it is just sucrose. In 2008, the Animal and Plant Health Inspection Service (APHIS), a division of the USDA, performed a court-ordered environmental review of the modified seed and announced that there was no risk to other crops such as beets (beetroot) for fresh eating and pickling, or related crops such as Swiss chard.

Hawaiian Papayas

Since 2010, at least 80% of papayas grown in Hawaii are GM, to get around the devastating problem of papaya ringspot virus.

 

Jubilee tomato in our hoophouse in early June. Not GMO
Photo Pam Dawling

The ‘Flavr Savr’ Tomato

Consumers in the northern regions of the U.S. rely on tomatoes shipped in from the South if they want fresh tomatoes beyond the summer. To survive shipping, tomatoes are picked at the “mature-green” stage. They have already absorbed all the vitamins and nutrients from the plant that they can, but have not started to ripen. To ripen the green tomatoes, they spend 3 to 4 days in rooms where ethylene gas is released, and are then shipped at temperatures not lower than 50 degrees, to preserve what flavor they have.  These tomatoes are probably still a few days away from being ripe.

Calgene, a biotechnology company, developed a tomato with a gene that slows the softening process that happens with ripening. Pectin gives tomatoes their firmness. The pectin in ripening tomatoes becomes naturally degraded by an enzyme and the fruits soften, making them difficult to ship.

The scientists “reversed” the tomato softening gene and reintroduced it into the plants. Reducing that enzyme in tomatoes slows cell wall breakdown and keeps the fruit firmer for longer. In order to tell if their “Flavr Savr” gene was successfully inside the plants, scientists attached a gene that makes plants resistant to the antibiotic kanamycin. By exposing the plants to kanamycin, they could tell which plants had accepted the Flavr Savr gene. Once in a tomato plant, the Flavr Savr gene attaches itself to the gene activating the softening enzyme. When the Flavr Savr gene is there, the “softening” gene cannot give the necessary signals to produce the enzyme that destroys pectin.

Production of the Flavr Savr stopped in 1997. Production costs were too high, and consumers did not find a benefit. See Whatever Happened to the Flavr Savr Genetically-Engineered Tomato

A ladybug on a potato leaf, looking for pests to eat. Ladybug larvae eat eggs such as Colorado Potato Beetle eggs. Not GMO
Photo Kathryn Simmons

NewLeaf (and other GM) Potatoes

 The NewLeaf GM potato was brought to market by Monsanto in the late 1990s. It was developed incorporating Bacillus thuringiensis (Bt) bacteria to kill Colorado potato beetles. The target audience of fast food retailers rejected it and food processors ran into export problems. It was withdrawn from the market in 2001.

In 1998, a safety study (Ewen and Pusztai 1999) of GM potatoes with incorporated snowdrop bulb lectin (GNA) gene (Lectin acts as an insecticide), showed significant changes in the intestines of rats fed GM potatoes. The tested potatoes were not a commercial variety and not intended for human consumption, but the public were alarmed.

In 2010 Amflora was developed by BASF Plant Science for production of pure amylopectin starch for manufacturing waxy potato starch. It was approved for industrial use in the European Union in 2010, but was withdrawn in January 2012 due to rejection by farmers and consumers.

In 2011, BASF requested approval for its Fortuna potato as feed and food. The potato was made resistant to late blight by adding resistant genes that originate in the Mexican wild potato Solanum bulbocastanum. In February 2013, BASF withdrew its application.

In 2014, the USDA approved a GM potato type, Innate, developed by the J. R. Simplot Company that contained 10 genetic modifications that prevent bruising and produce less (carcinogenic) acrylamide when fried. The modification uses RNA interference (deactivating genes already present), rather than introducing genetic material from other plants or animals. Ranger Russet, Russet Burbank, and Atlantic potatoes are examples of varieties using this technology. McDonald’s announced that they have ruled out using Innate.

In 2017 scientists in Bangladesh developed a GM variety of potato resistant to late blight.

Arctic Apples

In February 2015 Arctic Apples became the first GM apple approved for sale in the US. RNA interference is used to reduce the activity of polyphenol oxidase, preventing the fruit from browning.

Mushrooms

In April 2016, a white button mushroom (Agaricus bisporus), genetically modified using the CRISPR technique, received the go-ahead, as the USDA considers it exempt because the editing process did not involve the introduction of foreign DNA, just deletion from a gene coding for an enzyme that causes browning, reducing the level of that enzyme by 30%.

 The Problems with GMOs

When GM varieties are planted on a commercial scale, resistant weeds and pests can evolve. The emergence of resistant insects can negate the effects of a Bt GMO. Also, if herbicide spraying becomes more frequent on herbicide-tolerant GMO varieties, weeds can develop resistance to the herbicide. This can cause an increase in herbicide use or an increase in the amount and types of herbicides used on crop plants. It is not a coincidence that herbicide producers are behind this research.

Further investigation is needed to learn if residues from herbicide- or pest-resistant plants could harm soil organisms. Another uncertainty is whether the pest-resistance of GE crops can cross to related weeds, creating resistant weeds. Possibly insect-resistant plants can cause increased death rates to one specific pest, decreasing competition and allowing previously minor pests to become a major problem. Also, it could cause the pests to move to another plant that had been unthreatened. A study of Bt crops showed that beneficial insects are also exposed to harmful quantities of Bt. It is possible for the effects to reach further up the food chain to affect crops and animals eaten by humans.

It is possible that virus-resistance can lead to new viruses and new diseases emerging. Naturally occurring viruses can recombine with viral fragments, forming new viruses.

The main concerns about adverse effects of GM foods on human health are the transfer of antibiotic resistance, toxicity and abnormal immune responses. A known allergen may transfer from a GM crop into a non-allergenic crop and create a new allergen. Patients allergic to Brazil nuts and not to soybeans showed an allergic response towards GM soybeans.

  A Law on our Side

In January 2022 the National Bioengineered Food Disclosure Standard became mandatory. The new Standard requires food manufacturers, importers, and other entities that label foods for retail sale to disclose information about BE food and BE food ingredients. This rule is intended to provide a uniform national standard for providing information to consumers about the BE status of foods. The Final Rule was published in December 2018

 

Bioengineered Food symbol

The BE Food Disclosure must be placed on either the main information panel on the label, or an alternate panel “likely to be seen by a consumer under ordinary shopping conditions.” For bulk foods, retailers are responsible for displaying the BE food disclosure on or near the bulk item. Now you know what to look for!

More on Insectary Flowers; Vegetable Crop Resources, Especially Weeds

 

Borage flowers attract many beneficial insects. Spot the honeybee! Photo Raddysh Acorn

More on Insectary Flowers (to attract beneficial insects)

A reader responded to my post Growing flowers to attract aphid predators in early spring

“Isn’t too cold for the predators to be around, Pam? unless they hibernated in the greenhouse. but even so, it’s still cold in there at night. We have some aphids too in the tatsoi and some of the lettuce, so thank you for all the tips, and the life cycle. I had not quite realized that the cycle was so short. I grow borage in the hoophouse but in the ground – the plants get large and gorgeous with clouds of blue flowers in March and April – much bigger and healthier than anything I try to grow outside. The honeybees absolutely love it and they attract are a lot of other insects too.”

Yes, it has been still too cold for predatory insects to be around, until this week, when ladybugs greet us around every corner. Our idea with the flowering plants was that by starting the plants in the fall, we’d have actual flowers earlier than if we started in “spring”, and that perhaps the extra stresses would even cause the plants to flower earlier. Apart from the borage, none of the others have flowered yet (Feb 23). We likely need to fine tune our sowing dates. We sowed at the very beginning of September and the very end of October. That two-month gap probably has better sowing dates! We noticed that some of our plants were not very cold-hardy. Some died and some had to be pruned of dead bits. Since then, we started more flowers in our greenhouse on February 1. Another thing we’re noticing since early February is that the plants in pots dry out very fast. It’s probably better to get the flowers in the ground in the hoophouse and greenhouse as soon as they are big enough, as suggested by the results of my reader quoted above, with borage.We had thought that having them in pots would enable us to move them into trouble spots.

Vegetable Crop Resources, Especially Weeds

Spiny amaranth – a weed to exterminate by careful pulling.
Photo Pam Dawling

A newly released handbook from Sustainable Agriculture Research and Education (SARE), Manage Weeds On Your Farm: A Guide to Ecological Strategies by Charles L. Mohler, John R. Teasdale and Antonio DiTommaso, is set to help us all. I haven’t read it yet (although I am looking forward to that!), so this is not a review, But these are three big names in weed science, and SARE is well-known for providing solid information on sustainable farming.

Silver Queen sweet corn with a wilting pulled amaranth plant in the center
Photo Kathryn Simmons

I had the great good fortune to attend a workshop by Chuck Mohler years ago, and got some realizations that forever changed my approach to weeds. Top of the list is that some weeds, such as pigweed (amaranth species), don’t distribute any seeds until they have grown very big. Until that point they are not threatening next year’s farming efforts. We used to get huge pigweed plants in our sweet corn, and fatalistically did nothing once we were in there harvesting, somehow believing it was “too late”. No, it’s not! They hadn’t seeded. We started to make a practice of pulling the huge pigweed every two days while harvesting corn. Often it was necessary to stand on the base of the corn plant to hold it in place, while pulling the weed. Then all we had to do was drop the pigweed between the rows. Sweet corn ripens in hot weather and the weeds soon died, rather than re-rooting. All those big leaves sucked the moisture right out of the plants. Be extra careful if you have spiny amaranth. We have twice eliminated this weed form our gardens, by diligent hand-pulling, only to have it reappear a few years later!

Galinsoga – a fast growing, fast-seeding weed of cultivated soil.
Photo Wren Vile

Conversely, galinsoga forms seeds very soon after germinating, while still small. This weed is one to strike early and repeatedly. It readily re-roots in damp soil. Our strategy when we are too late to hoe and have to hand-pull them, is to shake off as much soil as possible, then to either twist and break the stem (if there are not many), or “shingle” the weeds, laying them down with the roots of one on top of the leaves of the previously pulled plant, providing a surface of roots all exposed to the air, and none touching the soil. This works quite well. Timely hoeing is much better, of course!

Manage Weeds has chapters on How to Think About Weeds, Cultural Weed Management, Mechanical and Other Physical Weed Management Methods, Profiles of successful managers,  and then the alphabetical rogues gallery of grass weeds and broadleaf weeds.

This book and all the online information from SARE is free of charge. You can buy print copies if that suits you better. Other good resources from SARE, while you’re at their website, include several other books:

Building Soils for Better Crops

Managing Cover Crops Profitably For many of us, this is the “Cover Crops Bible”

Systems Research for Agriculture

Crop Rotation on Organic Farms 

There are also podcasts, bulletins, videos, Topic Rooms and interactive pages to explore.

Winter Vegetable Production Methods

For those who missed the Pasa Sustainable Agriculture conference, here is my slideshow Winter Vegetable Production Methods, From the Field to the Hoophouse

Winter Vegetable Production Methods, From the Field to the Hoophouse Dawling 60 mins 2022 2.11 9am

Some Highlights of the PASA Conference

I enjoyed attending the in-person conference of Pasa Sustainable Agriculture. This is the first conference I’ve been to in person in two whole years. PASA did a lot to ensure the conference was as Covid-safe as possible. They limited the number of attendees (there were still plenty to ensure lots of chances to exchange information). Everyone had to test on their day of travel to the conference, and speakers had to test every day of speaking. For me that was all three days. Everyone was masked, nearly all with KN95 “real” masks. The hotel housekeeping staff only came in after we left. (We could have requested the service, but, heck, I can make my own bed!) In the workshop rooms, the chairs were spaced 6 ft apart. The trade show had wide aisles, and meals could be taken out of the dining room to a quiet spot. Just getting to be there was a big highlight for me! I left feeling energized and enthused, and very grateful to the PASA team for preparing such a successful event.

There were four sessions of workshops each day, with one-hour breaks between, allowing time to visit uncrowded trade booths, catch up with old friends, and make new ones. We were well-supplied with snacks and beverages during the breaks. There were socials with more snacks at the end of the day.

I did have trouble with the conference app, but then, my phone is limited in what it can do. Likewise I failed to upload my slideshows to the platform, so I ran them off my flashdrive. My pdf handouts did make it onto the app, so if you wanted one of my handouts, you can find it there and here:

Young Yukina Savoy plants.
Photo Ethan Hirsh
Optimize your Asian Greens Production Dawling PASA handout 2022 2.10 9am
Young spinach seedlings.
Photo Pam Dawling
Winter Vegetable Production Methods From the Field to the Hoophouse Dawling 2022 2.11 9am 6 page handout
Sweet potatoes in storage. An ideal crop for winter meals, as they store at room temperature for a long time, maybe seven or eight months.
Photo Pam Dawling
Growing Sweet Potatoes from Start to Finish Dawling 4 pg handout 2022 2.12 11am.docx

Each of the ten workshop sessions had a choice of eight or nine workshops. I had thought I might hunker down in my hotel room when I wasn’t speaking, to minimize my chance of catching Covid, but as permaculture author Darrell Frey said “This feels safer than going to the grocery store!”

I enjoyed several workshops presented by others, including:

On-Farm Experience with Organic No-Till

Sam Malriat from Rodale

No-Till sequesters carbon in the soil, but simply never tilling does not improve the soil. Chemical no-till uses lots of herbicide. Don’t be obsessive about no-till. Shallow tillage can be a responsible choice, as incorporation of organic matter is valuable. Adding cover crops, compost or manure, grazing, and a good crop rotation, can increase the OM, and thus increase the soil water capacity enormously.

Crimson clover cover crop
Photo by Bridget Aleshire

To overcome the challenges of no-till, you need a very good cover crop stand that will provide a thick mulch when terminated; a competitive cash crop; a way to plant into the residue, and a back-up plan in case one of the requirements doesn’t pan out.

Sowing corn into rolled and crimped hairy vetch does not work well, because corn is a heavy feeder and not very competitive. Better is to undersow the corn at V5 or V6 (stages of vegetative growth) with white clover or crimson clover in September. It’s important to get good seed to soil contact. The clover grows when the corn dies. This is in Rodale Country in PA. If the clover can be left growing until the second year, cabbage can be transplanted into it. His slides showed the success of this system after an unpromising start.

Pumpkins can be direct seeded in crimped and rolled (or mowed) winter rye. There is a lot of difference in thickness of the mulch between rye sown in August and October.

Organic Solutions: Pest Management

Drew Smith and Emily Gantz from Rodale

There was a big drop in pesticide use in the mid 1990’s as GMO crops came in. But then a big uptick as resistance to the GMO crops developed. Currently, almost all non-Organic seeds contain neo-nicotinoids, even though they provide no economic benefits.

Crop rotation is the single most important thing you can do to manage pests. Drew showed us the IPM triangle, and we worked our way up. To succeed in preventing pest infestations, planning of all aspects of growing the crop is vital. As is regular scouting of each crop. Cultural controls include the physical aspects of the planting. Other physical controls include mechanical aspects of growing the crop. Biological controls include encourage beneficials, releasing biological agents. Greater biodiversity provides greater stability. See Cornell Entomology https://biocontrol.entomolgy.cornell.edu/index.php

Native Pollinators: Identification, Habitat Needs and Resources

Sarah Koenig and Ryan Stauffer from the Audubon Society

A bee pollinating squash.
Photo Pam Dawling

There are 4000 species of bees in the US (20,000 globally). 70% of food crop species rely on honeybee pollination to some extent. Native bees mostly nest in the ground. Don’t kill them by compaction (or weedkillers!). Use native flowers to attract native pollinators.

Using Tarps to Reduce Tillage on Small Vegetable Farms

Ryan Maher, Cornell Small Farms & Bob Tuori, Nook and Cranny Farm

More growers are trying tarping for weed control, killing cover crops, maintaining a good soil temperature, avoiding crusting and compaction, keeping beds dry enough for planting and reducing dependence on single-use plastics. Challenges include the heavy weight, the aggravation of using sand bags, especially in windy places, ponding of rainwater runoff, and the frustration of providing perfect vole habitat.

After 28 days in summer, you gain 200 GDDs. Plant-available soil N increases by 2 or 3 times from the plant residues. How soon does it dissipate after removing the tarp? Tarping for 3 weeks after shallow tilling kills the living weeds, improves crop establishment and reduces weed emergence by up to 83%. Think of tarps as a tillage tool! Do plan for weed management after removing the tarp. Pigweed and amaranth can become worse!

We haven’t tried tarps yet. Early September photo of hay mulched June-planted potatoes.
Photo Kathryn Simmons

Bob Tuori spoke about a SARE trial of tarping in the Northeast. He compared potatoes grown with and without prior tarping, both patches with and without hay mulch after planting. The tarped area needed sandbags every 10-15 ft. The tarp was removed June 4, weeds were counted June 24, then the patches were mulched. (I hope I got that right). I did not write down all the results, but the only-mulch area grew 17.4 lbs per hour of work, and the tarp-only area grew 13 lbs per hour of work. See the SARE report for the details.

Harvesting Techniques for Small- to Mid-Scale Vegetable Farms

Julie Henninger of Good Keeper Farm and Matthew Lowe

We saw good tool and equipment storage, and learned the benefits of growing head lettuce on landscape fabric (no rotten bottom leaves, no weeds). Muir is their favorite lettuce for spring, summer and fall. At $3/head, a 95ft row planted at 9” spacing earns them $1300, if they have a 15% loss.

Beautiful baby lettuce mix in our hoophouse.
Photo Wren Vile

We learned the importance of sharp knives or scissors for cutting baby greens with minimal cell damage and browning. Theirs sells at $12/pound. They grow Salanova, which brings in $1140/bed at each cutting. If they cut whole heads, these bring in $1476 per bed.

For loose carrots, they sow rows in pairs 2” apart, with 6 rows on a 30” bed, using a stale seed bed and flaming. They sell 1000 lbs per week. Julie Henninger emphasized not wasting time by setting the carrots down in piles. Minimize the number of times each crop is touched. They have modified a cement mixer to wash 25-45 lbs at a time.

Training and communication are also very important. New workers must master the task first, before chatting. Minimize distractions. Send crews out with a strong role model each, to keep the crew working at a sustainable pace. If working with a crew with diverse abilities (eg children), provide a clear short task with a beginning and an end, to give a good sense of achievement.

I also attended the Plenary, Why Is Farming So Hard & What Can We Do About It?  on Friday with Brennan Washington, Sarah Mock and Dr Jessica Gordon Nembhard, who were livestreamed and recorded.

I participated in the book swap, setting out some spare handouts I had in exchange for a couple of magazines. I enjoyed the Farm Innovations poster display of tools and techniques to improve production or save resources (or both). I liked that previous years’ posters were available as pages in several ring binders.

In the Trade Show there were 60-odd vendors. I checked in with Nifty Hoops, a company who will deliver a hoophouse and put it up for you in one day, or help you put it up, teaching as you build. We put ours up ourselves, in 2003, and we were inexperienced and slow, and had to work on it in the (hot) afternoons, after spending the mornings farming. At events when I talk about hoophouse growing, I’ve sometimes been asked if there are companies who will erect hoophouses (high tunnels), so it’s good to be able to pass on this contact. Nifty Hoops also sell interesting components such as DC-powered inflation blowers. (734) 845-0079.  They have videos on their Facebook page

I picked up some publications from ATTRA, who have supplied me with great vegetable growing info since before the internet. (We used to call them up and ask for publications to be sent in the mail).

The Mini-Treffler manual harrow

I also was fascinated by the Mini-Treffler, from OrganicMachinery.net, a manual rolling tine harrow for crops in beds.

  • The TINY Treffler is a hand drawn harrow with the working width of 80cm (2 ft 7 in), 100 (3 ft 4 in) and 130cm (4 ft 3 in)
  • Shares the same principle with the big Treffler harrows: in the row harrowing, adjustable tension and the patented tine suspension
  • Each tine follows the contour of the field and the downward pressure remains constant
  • The TINY is effective throughout the growing season in greenhouses or for small enterprises in vegetable production or seed propagation
  • Wheels extendable from one or both sides to straddle a bed

I gathered literature for our garden crew as well as our dairy, orchard and poultry people, and an assortment of free pens, notebooks, stickers.

PASA also had a virtual conference, spread out over a couple of weeks in January. I’m sure there was great information there too, but our rural internet is not up to the task of virtual conferencing, so I’m in the dark. Pasa intends to keep a virtual conference next year as part of the mix – it works better for farmers who cannot easily leave the farm, it reduces the carbon footprint of travel, and saves on travel and hotel or BnB costs. Maybe next year I’ll have better internet. Maybe Covid will have receded. This year’s conference was great! I look forward to next year’s!

 

Growing flowers to attract aphid predators in early spring

Borage flowering in our hoophouse in January, among the lettuces. Photo Pam Dawling

Last July, when sheltering indoors from the heat, planning next winter and spring’s hoophouse crops, I researched and wrote up Controlling Aphids in Early Spring

I also have a post (another July information-gathering project!) about Insectary Flowers to Attract Beneficial Insects outdoors and in, at various times of year. At the end of April we sow several plug flats of different flowers to plant out in Insectary Circles at the ends of our outdoor raised beds. We hope to find a similar approach that will work earlier in the year for hoophouse and greenhouse aphids.

Ladybugs of Maine
Poster from the Lost Ladybug Project

Aphid predatory insects such as ladybugs, lacewings, aphid  parasites, damsel bugs, braconid wasps, rove beetles, syrphid flies, and spined soldier beetles are attracted to plants with small flat open flowers, like alyssum, dill, yarrow, buckwheat, sunflowers, and cosmos. This is a rather loose and general statement. On a big scale this is known as Farmscaping, and you can read about it in a publication from ATTRA; Farmscaping to Enhance Biological Control . You can use this publication to make a specific plan to tackle particular pests. Ladybugs are a good general help because they eat the eggs of many different pest species. Organic Integrated Pest Management from ATTRA gives wider information about managing pests organically.

 

Ladybugs of South Dakota
Lost Ladybug Project

eOrganic has many articles on Insect Management in Organic Farming Systems, that explain ways to tackle pest problems with ecologically-based practices, starting with actions chosen to reduce the chances of the pest ever getting a grip on your crops.

Aphids can get out of control in early spring in our greenhouse and hoophouse, as they become active before their native predators, such as ladybugs, emerge from hibernation. We have a particular problem in our hoophouse and in our greenhouse on the eggplant, pepper and tomato transplants from mid-April to mid- to late-May depending when we manage to get them under control. We are implementing our plan that we made in the summer.

Insectary flowers against aphids

Meanwhile in January we got bad aphids on the lettuce and, of our flowers to attract beneficials, borage was the only one flowering. It was not enough. We did three sprays of soapy water at 5 day intervals to kill the aphids.

Pepper plant with aphids. Photo Pam Dawling

There are many kinds of aphids. The lifecycle of aphids starts in spring with eggs hatching into wingless females that give birth via parthenogenesis to more females. Within a week, one female can produce 100 clones, which can repeat the process at the age of one week.  This continues until adverse weather or predators trigger production of a generation of winged female aphids that moves to new plants. Later in summer male aphids are born and females lay fertilized eggs that overwinter on host plants, to hatch the following spring.

This week, I want to give a progress report on the flowers we are growing. The chart gives details of the ones we chose, where we found the seed, and which months we decided to plant them in.

September-sown Borage flowering in our hoophouse in January. Photo Pam Dawling

The first planting, in September, was of borage and shungiku (Chrysanthemum greens) only. We hoped these would give us early flowers to start the program. Those plants became big enough to transplant in the ground and in 8” (20 cm) pots. We thought having some in large pots would enable us to move them to the trouble spots.

September-sown shungiku (chrysanthemum greens) in January.
Photo Pam Dawling

What I have noticed is that plants in pots dry out very quickly in both the hoophouse and greenhouse! The shungiku have looked close to flowering several times, and the accidentally dry conditions should have helped them to panic and bloom, but they haven’t. The borage flowered with pompom-like clusters, much more compact than spring outdoor borage does.

October-sown Meadowfoam plants in our hoophouse in January. Photo Pam Dawling

The second planting, in late October, consisted of Meadowfoam, Tidy Tips, Phacelia and Yarrow. Those plants are still small, as I write this at the beginning of February.

October-sown Phacelia in January. Photo Pam Dawling

They have been potted up from cells to 4” (10 cm) pots, and some are ready for bigger pots. No flowers, no help against January lettuce aphids.

October-sown Tidy Tips(and more phacelia) in our hoophouse in January.
Photo Pam Dawling

The third sowing has just happened, on February 1, and includes borage, shungiku, Meadowfoam, Phacelia, Tidy Tips and yarrow. I forgot to sow alyssum, so that will be a little later.

Slow-growing October-sown yarrow plants in January, using space in the path between lettuce beds. Photo Pam Dawling

The September-sown borage and shungiku both had some troubles with cold temperatures during January. We had a mild December, then a January with three non-consecutive nights at 10F (-12C). In our double-poly hoophouse, we roll out rowcover at night if it threatens to be 8F (-13C) or lower outdoors. That was about 6 times so far, but 10F (-12C) has been our coldest. Some of each of the borage and shungiku got cold-damaged, and some got rowcover-damaged (hasty pulling!)

So far, no beneficials have been seen on the borage flowers, and no aphids have been killed as a result. We’re still hopeful, especially about reducing aphid numbers on the peppers. More progress reports to come!

Flowers Against Aphids! Photo Pam Dawling

 

 

Preparing for Spring Transplants

Seed flats in the greenhouse in early spring. See the large lettuces growing in the beds, between flats of seedlings balanced on the bed walls.
Photo Kathryn Simmons

Preparing for Spring Transplants

We have winter to enjoy/experience/endure before we start spring seedlings, but there are some steps you can take to make spring start-up easier and more successful. Of course, there is the usual list of tidying your workspace, preparing to order seeds and repairing tools.

Replacement tool handles

House Handle Company   Telephone: (800) 260-6455 has a wide selection of good quality wood handles online. They specialize in hickory, white oak and ash. Be careful making your selection, and get the handle that’s just right for the tool you are repairing. You can see a lot of their handles in our photos. During the winter we usually have a “Santa’s workshop” day when we repair tools.

There are YouTube videos showing how to make sturdy repairs. Just be sure to shape the handle for a good fit before drilling any holes for rivets. And learn how to make rivets from large nails if none are supplied with your replacement handle. Sharp edges on poking-out badly finished rivets, or nuts and bolts can cause injuries. Sweat we might need. Blood and tears we can do without.

Screening a large pile of compost for the greenhouse beds. Photo Wren Vile

Seed Compost

Today I’m thinking about seed and potting compost.

We use 100% home-made compost for sowing seeds, and for potting-up transplants. We don’t mix in any other ingredients. Our seed compost is our regular good-quality compost, screened to remove large particles, and matured over the winter into a very mellow combination of nutrients and micro-organisms. We make great compost and it grows big strong plants.

We screen a big pile of compost in September, and fill the cinder-block beds in our solar-heated greenhouse. See this post: Screening compost to make our own seed compost for spring. If you are making your own screens, you can use hardware cloth (rat-wire), or do as reader Jim Poole suggested and try stucco lathing instead. “It is quite a bit sturdier. (But watch out for the cut ends when installing it- it can give you a nasty gash.)”

We need a lot of compost, but the idea works fine on a smaller scale too. Find an indoor place near where you will use the compost in the spring, and some tubs to put the screened compost into. If you want the full tub to be on a bench in spring, put the empty one on the bench and screen into it! If you want to grow lettuces in the compost, put the tubs near a window.

Just storing the compost inside over the winter will mean you are not dealing with frozen stuff when you want to sow. But better yet, see Starting Seedlings and Preparing for spring, sowing seeds, for more about how we grow lettuces in the stored compost over the winter in our greenhouse, then use that compost in spring for seedlings.

Greenhouse beds filled with screened compost.
Photo Wren Vile
Lettuce growing in screened home-made compost in our greenhouse in November.
Photo Wren Vile

We transplant lettuce at 10″ spacing into the beds in mid-September or early October. By harvesting only the outer leaves, we keep those lettuces alive and growing all winter to give us salad from November to February. Because we water the lettuces, the compost organisms stay alive and active. If you don’t grow a crop overwinter, water the compost from time to time to keep it slightly damp.

This system provides us with a large quantity of mellow screened compost for seed flats, indoors and not frozen. The micro-organisms have had plenty of time to colonize the compost, so it is full of life. In spring, as we need space in the greenhouse, we pull the lettuce. We can then scoop out the compost to fill the flats for seedlings.

Aphids

The only issue we sometimes have is aphids in early spring. This winter we are experimenting with some plants we hope will flower in early spring and attract beneficial insects who also eat aphids. I’ll report on this project when we see the results.

Here’s what we currently do to deal with early spring greenhouse aphids:

  1. jet the plants with water to project the aphids into outer space (OK I’m exaggerating),
  2. gather up lady bugs, or
  3. if numbers of aphids are really high, we use a soap spray.

We start our first seedlings in mid-January, although we only sow a few things the first week (cabbage and lettuce for outdoors and tomatoes for our hoophouse), and harvesting just one or two lettuces would provide enough compost for those few flats.

Lettuce transplants in soil blocks. Photo Pam Dawling

Soil blocks

We used to make soil blocks for our more delicate transplants (melons, early cucumbers and squash) because there is no transplant shock when you plant them out. We even used them for lettuces at one time. We developed a very simple recipe, which we seem to have lost, but it was something like 1.5 parts by volume of our home-made compost, 1 part of soaked coconut coir and as much water as needed to make a wet slumpy, but not soupy, mix.

I use coir rather than peat moss, because I believe the extraction rate of peat moss is not sustainable, and as a carbon sink, it’s better to leave it in the ground. Coir is a tropical food by-product. I’m sure it’s better returned to the soil where the coconuts are grown.

The mix is compressed into a special block-maker, which is then scraped across an edge of the container of mix, to create a flat base, and then the block is ejected using the spring-loaded handle into a tray or open flat. We line our flats with a sheet of plastic to reduce drying out. It’s important to dunk the block maker in water between fillings to wash off the old remnants and enable the new blocks to slip out smoothly.

The blocks are surprisingly stable – they can be picked up and moved, like brownies. Or you can move several at once on a kitchen spatula. As the plants grow, the roots get air-pruned. Even if you pack the blocks shoulder to shoulder in the tray, the roots from one block do not grow into the others. There is no root damage at all when the complete block is transplanted. Do make sure you press the surrounding soil down and inwards to make good contact with the block.

Okra seedlings in a Winstrip tray in the greenhouse. Note the vented cell sides.
Photo Kathryn Simmons

Winstrip trays

More recently we have come to love Winstrip trays, very durable plug flats with cubic cells that are vented down the sides, so the plants get air-pruned. The bottoms of the cells have finger-sized holes so you can easily pop a full-grown transplant out of the tray. The Winstrip 50 cell tray has cells almost the size of soil blocks. These flats have all the advantages of soil blocks except price. They are expensive. We got ours used. Winstrips have two additional advantages: they are much quicker to use than soil blocks, and they work with all-compost. We don’t add any coir. One less input to buy. I haven’t calculated how many plugs-worth of coir pay for one Winstrip tray. . .

See this post on using Winstrip trays and transplanting plugs from them

For more about soil blocks, and Winstrip and other plug flats, see my book Sustainable Market Farming

Book Review: Vicki Hird, Rebugging the Planet

Vicki Hird, Rebugging the Planet:

The Remarkable Things that Insects (and Other Invertebrates) Do – And Why We Need to Love Them More

Chelsea Green Publishing, September 2021, 224 pages, $17.95

Vicki Hird has a passion for insects, and this book brings home to us how much depends on the well-being of invertebrates in the world. Insects are a cornerstone in our ecosystem, and we must reverse the current dangerous decline in bug populations (40% of insect species are at risk of extinction and 33% more are endangered). We are heading towards “Insectageddon.” After reading this book, I found myself being much more careful about gathering up insects inside the house and taking them outside, where I imagine they will thrive better. Did you know that spiders rest calmly in your gently closed hand? They do not wriggle and tickle!

We need to overcome any aversion or indifference to creepy-crawlies, and change our attitudes to respect, appreciation, and some humility if possible. Insects pollinate plants, recycle waste into nutrients, control pest species, add air channels in the soil, and ultimately return themselves to the soil food web.

Fall spiderweb photo from Ezra Freeman

Vicki explains how to rebug our city green spaces, grow gardens without pesticides and weedkiller, teach children to appreciate small creatures, make choices that support insect-friendly (planet-friendly) production of food and fiber, and make wider choices that affirm human dignity and equal rights.

This book has charming insect drawings, and delightful anecdotes: “I was never going to get the pony I wanted, so I settled for an ant farm at an early age.” Studying biology at school led Vicki to a summer job observing bees at a research station. A later job investigating cockroaches led her to respect them and realize that it is humans that need better control, more than roaches do.

Vicki has been an environmental campaigner, lobbyist and researcher for about 30 years, and is the mother of two children. Vicki is also head of the Sustainable Farming Campaign for Sustain: The Alliance for Better Food and Farming, a UK alliance of organizations and communities advocating for healthy food, people and environment, and equity in society. She has a website for Rebugging.

Those over 50 (and maybe 40) will have noticed that long car drives no longer lead to cars covered in smashed bugs. There are fewer butterflies. More than twice as many insect species as vertebrate species are at risk of extinction. I noticed on a trip to England after an absence of a couple of years, that the number of sparrows has plummeted. We are more likely to get distressed about the charismatic mega-fauna, but less so about formerly ubiquitous sparrows, and even less about insects. There may be 4 million unidentified species of insects (as well as the million we know). In the UK 23 bee and wasp species have become extinct since 1850.

So, what is ‘rebugging’? It is a form of rewilding (the introduction of similar-to-natural ecosystems and missing species into an area and then waiting to see if the species can settle in). It is somewhat controversial, and alone is insufficient to cause all the changes we seek. We also need changes in policy, lifestyle, and civic involvement. This book provides information, encouragement and tools to act.

Sunflower bee and bug.
Photo by Bridget Aleshire

What would the world be like without bugs? “A great image that has been doing the rounds is a picture of a bee saying, “If we die, we’re taking you with us.” It’s not an empty threat, but a fact – we would not last long without insects. Our flowering plants would die off; all the species that dine on insects would be lost, followed by the next ones up the chain; dead animals would pile up undigested; trees would cease growing in the compacted airless soil.

But this is not our inevitable future. We can step back, as we have done when the dangers of DDT, CFCs, and nuclear weapons became blindingly clear. We can work to restore habitat, reduce damage and make political and economic structural changes at all levels in society. We can start by “rebugging our attitudes.”

How can we protect and nurture invertebrates? We can help research what’s out there. We can encourage others to be concerned and take action to protect invertebrates. We can teach others about the value of insects for human well-being. We can make havens for wildlife, convert every city street into a biocorridor, share designs for pollinator-friendly gardens, encourage conservation of water and other natural resources, make urban farms and community gardens.

The book is studded with sidebars on aspects of the value of insects, such as “How much is a bee worth?” (The answer is over $3,000 per hectare in pollination services, for wild bees) That’s more than 651 million GBP to the British economy.

Insects are food for many animals such as poultry, fish and pigs. And some insects could be food for humans. I ate a 17-year cicada last time they were in our area (2013). I was partly inspired by Jackson Landers’ book Eating Aliens. And really, if you can eat shrimp, you can eat meaty insects. But Rebugging isn’t mostly about eating insects, but rather preserving their lives, and benefiting from their contributions.

If you are still unsure what bugs do for us, the second chapter spells it out. We would be knee-deep in manure, leaf litter and dead animals within weeks, if there were no bugs eating it all, and enriching the soil. Tardigrades (water bears or moss piglets) are the most resilient animals known, able to survive extreme temperatures, pressures, dehydration, oxygen deprivation, starvation and radiation. They can remain in suspended animation for years until conditions improve. They have already survived all five mass extinction events, and some have been revived from a hundred-year-old sample of moss in a museum. Respect, please!

A ladybug on the leaf stem of a sunflower planted to attract beneficials.
Photo Pam Dawling

Avoid spraying wasps with pesticides-in-a-spray-can. They are as useful as bees and ladybugs, and are the best pest control we have for hauling away cabbage caterpillars. If you are more motivated to provide accommodation for ladybugs than wasps, keep moist dark places like old hollow stems, bark pieces and logs where the adults can overwinter. I could really use some early-spring-wakening ladybugs in our hoophouse to tackle the aphids!

Carefully introduced biological bug control can reduce the amount of pesticides used. A scientific risk assessment is an important first step, though. The 1930’s introduction of cane toads in Australia for pest control was a terrible mistake. The toad was a worse pest than the bugs had been. There are many more success stories than disasters!

Vicki Hird, Author of Rebugging the Planet

Rewilding can be complicated – looking at a huge overgrowth of creeping thistle is alarming. Happily, the biggest migration of painted lady butterflies came over and laid eggs on the thistles. The resulting spiny black caterpillars ate the thistles down to the ground. UK organizations have been creating maps of “insect superhighways” they are calling B-Lines, that will be filled with wildflowers so that insects and other wildlife have continuous corridors to travel from one area to another. There’s a two-page spread of possible actions to help the rebugging process, starting with publicity and education, and moving onto helping build bug-friendly habitat in public places and workplaces and private gardens.

Green public spaces can include a wide variety of invertebrate species. Look on derelict land, in cemeteries, along grass verges, and even on golf courses. Many companies and local authorities are now wanting to manage their land in ways that support more wildlife, and with encouragement might move another step in that direction. Tiny public orchards and forests are being planted in some places. There is a sidebar of actions to reduce deliberate, accidental, and thoughtless damage to insects.

After starting small and local, you might be ready to expand your ambitions and commitment. The overall total mass of insects is estimated to be falling by 2.5% every year. One big factor pushing species towards disaster is climate change. This is a big one to tackle, and yet we must. Overwintering numbers of monarch butterflies (the celebrities of the insect world) have dropped to less than 1% of their 1980’s population. Yes, compared with 40 years ago, the population is now just 1/100 of what it was. When food species arrive, peak, or leave earlier in the year due to changed temperatures, the predator species goes undernourished. Pesticide contamination gets a lot of blame too.

A bee pollinating squash. Photo Pam Dawling

Water pollution also harms diversity. Leached fertilizers in estuaries have created ocean dead zones. Combating climate change might not be what you expected to read about when picking up a book on rebugging the planet, but it is vitally connected. We can learn from bugs about climate management. Honeybees have learned how to mob an invading Asian giant hornet and cook it to death. In Brazil, scientists discovered an area of 200 million termite mounds each spaced 60 feet from its neighbors. This is all one colony, connected underground. Some of the mounds are over 4,000 years old. They have created a stable environment for millennia. The methods of ventilation and gas exchange could be copied for human habitation.

Are 5G phones heating insects 370% above normal levels and cooking them in the electromagnetic fields they generate? It could be true, based on research on models. The action list at the end of this chapter urges us to avoid 5G phones if we can, and not to use them outdoors if we must have one.

The chapter on why our farming, food and shopping all need bugs opens with a discussion on almond milk. The “dark reality” is that huge almond plantations need millions of bees brought in every year for pollination. Thousands of colonies are moved in to California’s Central Valley, for example. 30% of these bees die, because the environment is hostile, devoid of crops other than almond trees. Local wildlife cannot survive either.

It is a mistake to think that all vegan milk-substitutes are environmentally better than all dairy milk. It takes roughly 4 gallons of water for every gallon of milk a cow produces. Almond milk is much more intensive on water use: it can take up to 101 gallons of water to grow 1 cup of almonds, plus another 3 or 4 cups of water to manufacture almond milk. In fact, many commercial almond milks only have about 2% of almonds in them – the rest is water!

Bugs and other small animals can thrive in pastures if the livestock management is done well. The stock numbers and types are important.

Did you know that more than 70% of the world’s fish stocks are over-fished, depleted or collapsed?

We could also consider the impact of our decisions about textiles, timber and metals, on wildlife and ecology. The average person in the UK now buys over four clothing items a month! Less than 1% of clothing textiles is recycled. The waste mounts up. Forests are destroyed to make way for cotton plantations. Even if organically grown, cotton monocultures destroy habitat of thousands of species of butterflies, moths, termites, wasps, bees, and other bugs. Ironically, the cotton crop is then a sitting target for the bollworm moth. Genetically modified cotton was developed to overcome bollworm problems. A few countries resisted the siren call of GM cotton, and use integrated pest management (IPM) instead. They have lowered costs and increased yields.

While worrying about cotton, let us not forget synthetics and the huge problem of microplastics. In 2016, for example, 65 million tons of plastic textile fibers were produced. They do not decay. They are found everywhere on the planet, from the Arctic to the ocean depths. Ingestion of microplastics causes problems for marine life. The dyes cause disease, and can kill corals.

The action list for this chapter focuses on reducing waste. Think before you buy, think before you throw away. If you can, switch to consumption of locally sustainably produced goods.

Front and back covers of Rebugging the Planet

The action lists that close each chapter get longer, the connections get wider. Politics and the economy might not be the direction you expected from this book, but these topics are all part of the connected system, and all need consideration and action. Termites and corals co-operate within their colonies to create and maintain large healthy populations: we can do it too. (Corals are symbiotic associations of bugs (coral polyps, which form the exoskeleton) with several thousand species of animals and plants living within. Algae provide oxygen and carbohydrates.)

Big investors own shares in seed companies, just to make money. They have no interest or incentive to protect bugs or any aspect of the ecology. “It’s as if some beetles decided to take all the ants’ food supplies even though they cannot eat or use them. Money accumulation is hard to eat.”

Frustratingly, vested interests have too much power in decisions that affect large groups of people. We tend to avoid tackling entrenched societal problems. Vicki suggests three big areas to understand and deal with: poor governance and politics; inequality and poverty; runaway consumerism and waste. If you only wanted to read about saving beetles, you might be tempted to put the book down at this point. However, in order to save beetles, we need to look at the underlying causes of beetle die-offs.

Decisions on land use are often made by corporations and investors less focused on protecting biodiversity, and more on profits. We need to show them that enlightened self-interest can protect their financial success for the long haul. Some corporations are seeing this now that climate chaos is biting hard. Pushing humans to get three-quarters of their calories from just four crops (soy, wheat, rice and maize) may bring in fast bucks, but gives little resilience against climate change and extreme weather conditions, and is bad news for biodiversity.

Research has shown that as social inequality grows, so does harm to biodiversity, which leads to more inequality. Financial pressure from profit-seekers drives down wages, leading to a demand for ever cheaper food, spiraling to lower costs of production. They wring out higher short-term yields. Sustainability of food production goes to the wall. Desperate people take desperate measures to cover their basic survival needs. In 2020, the UN announced: “to bend the curve of biodiversity loss, we need to bend the curve of inequality.”

The action list for this chapter is over 5 pages, demonstrating the broadening of the goals. Campaigning, lobbying and voting; pushing governments and economists to balance social and environmental concerns and work for sustainable outcomes; requiring corporations to show much stronger accountability for all the results of their activity; supporting companies that are taking steps to lower their environmental damage and increase co-operation with others, strengthen international treaties and hold nations to their commitments on biodiversity and limiting climate change.

This probably sounds overwhelming, but “You don’t have to rebug alone”! You can join (or start) local organizations working on an issue you feel strongly about. The book contains a directory of some organizations (mostly in the UK). There is some help on starting lobbying, which most of us have not done before. The resources include guides on campaigning and influencing people. You can reduce your own carbon footprint and encourage others to do so. Big change is needed, but some days it’s restorative to “clean our own house” rather than go out lobbying.

 

Book Review: Sally Morgan, The Healthy Vegetable Garden

The Healthy Vegetable Garden
Photo Chelsea Green

Book Review: Sally Morgan, The Healthy Vegetable Garden: A natural, chemical-free approach to soil, biodiversity and managing pests and diseases.

Chelsea Green Publishing, September 2021

Sally Morgan is an expert organic gardener in the UK. She is the editor of Organic Farming Magazine for the Soil Association, the nation’s foremost non-profit organic gardening and farming membership organization. Her book The Healthy Vegetable Garden is clearly and concisely written. Sally promotes building healthy soil, boosting biodiversity, creating habitats to attract pollinators and predators, making good use of water, promoting the stability and resilience of natural ecosystems, and integrating the landscape with people.

A healthy garden maintains a balance where pest organisms are at a non-damaging level, (rather than eliminated entirely). Here you will find lots of solid information to identify pests and diseases and deal with them using regenerative principles, and when necessary, making traps and lures.

The book has some info particularly for US gardeners – you’ll be able to read about Mexican bean beetle and Colorado potato beetle! You might be mystified by some of the European details we don’t have to deal with, such as raspberry beetle or flatworms. As long as you have some prior gardening experience where you live now, you can only benefit from the information offered here. Brand new US gardeners might get confused.

The Healthy Vegetable Garden has good descriptions of soil and its components, structure, assessment, and testing. It is important to nurture healthy soils producing healthy plants, with the essential minerals and vitamins we need for health. Nutrient density has declined seriously over the last 70 years, particularly levels of calcium, iron and vitamins B and C. In 2014, the UN warned that we had only 60 years of harvests left, if we continued degrading our soils. In 2020 a new study estimated that 90% of soils had only 100 years of harvests left. Soils managed with conservation techniques have much longer projected lifespans.

The second chapter is about ways to regenerate soils, by minimizing tilling or digging, adding compost, mulches and cover crops. The living mulch section is where I am hesitant. My experience and that of Jesse Frost whose Living Soil Handbook I reviewed recently, is that living mulches can out-compete the crop if we are not skilled and careful. The author does point out the need to cut back the mulch to prevent this problem. Growers in the south might find planting zucchini (courgettes) into white clover impractical as zucchini is a fast-turnaround crop for us, whereas clover is a slow-growing cover crop. The author leaves the clover growing through the following winter, to make the combo work. In the chillier parts of the UK, only one crop of zucchini can be grown in a summer, so the system makes sense. In Virginia, we plant zucchini and summer squash 5 times outdoors. Likewise, the speed with which chickweed flowers and sets seed in Virginia would make it unwise to regard it as a cover crop! I did like the idea of undersowing tomatoes with coriander, if I wanted large volumes of coriander (cilantro).

Chickweed flowers.
http://ipm.ucanr.edu/PMG/S/W-CP-SMED-FL.006.html
Photo by Jack Kelly Clark.

The chapter on understanding pests and diseases is well-written, although we in the US have so many more than in the UK! Plant pests are listed in categories by their method of causing harm, rather than by individual names, which helps understanding. Plant pathogens likewise are described by type, as bacteria, viruses, fungi, water-molds. Fungal pathogens include biotrophs (parasitic pathogens such as downy mildews, rusts and smuts), semi-biotrophs that spend part of their lifecycle on the host, then part feeding saprophytically on the host’s dead remains (such as apple scab, Phytophthora blights, Botrytis-type molds and powdery mildews) and necrotrophs that kill their host and then feed as saprophytes. I appreciated the bigger understanding this classification of pathogenic fungi gave me.

Heed the warning that climate change is bringing new pests and diseases, and the chilling news that for every 1 Celsius degree rise in average temperature (about 2 F degrees), aphids become active two weeks earlier. Some warm climate diseases will move further towards the poles. The author recommends paying attention, encouraging good airflow around plants, sanitizing pruning tools, and planting rows of tall plants to break up the progress of air-borne fungal spores.  Growing potatoes downwind of a row of Jerusalem artichokes is a good example.

Sally is very practical on the subject of sterilizing pots and flats – your tools, boots, gloves and hands are as likely to spread spores, don’t worry about sterilizing pots! Some of the disinfectants suggested in other books can do more damage! Likewise, most spores don’t survive long on the ground, removed from their host plants, and so such diseased crops can be safely composted in a hot compost process. Practice crop rotation to deplete those that do survive in the soil, such as carrot rust flies.

Under normal conditions, predators can prevent pest outbreaks, but problems arise when conditions change quickly and disrupt the balance of prey and predator. If you see lots of pests, find a way to deal with them that won’t also kill their predators and parasites. Beware broad spectrum pesticides and fungicides, even if Organic. Encourage ladybugs and beetles by creating “ladybug hotels” and “beetle banks”. (There are some photos to inspire you.)

Plant for a continuous supply of insect-attracting blooms. Yarrow, ajuga, alyssum, dill, and fennel flower early in the year and attract predators like hoverflies, ladybugs, lacewings, tachinid flies, and parasitic wasps. Also grow early blooming flowers with pollen and nectar predators can use as alternative foods – borage is fast at producing nectar, as are dandelions. Phacelia is a very attractive to predators, especially aphid predators like hoverflies and parasitic wasps. Sow in the fall for early spring blooms. Angelica is a biennial that can flower in the spring of its second year. If you decide to trust to weeds to feed your beneficial insects, take care about how much seed they sow! This is a risk I do not recommend taking, especially in warm climates with rapid rates of growth.

Borage in an insectary circle.
Photo by Bridget Aleshire.

In the section on crop rotations, polyculture and continuous cropping, Sally reports that she has moved away from a rigid crop rotation for many crops, following Elaine Ingham’s observation that nature does not rotate. This may be a place where home gardeners and production gardeners diverge. Mixed beds with several crops work well for manual work, but less so for those with rototillers, or even those hoping to make fast progress with a scuffle hoe. Mixed plantings are attractive and fun for the solo gardener, but having others pull up your delightful medley suggests it doesn’t work so well for bigger operations.

This book is not dogmatic. Rotations help disrupt pest and disease cycles, and here you can read brief descriptions of three-crop, four-crop and eight-crop rotations. You can also devise ad-hoc rotations and grow beds of different crops next to each other, in order to benefit from diversity without slowing down your hoeing or putting a bed out of commission while you wait for the last item in that bed to finish its lifecycle.

Shumei Natural Agriculture Farm, Yatesbury, Calne, in SW England has been increasing yields year by year, with no rotation, no pesticides, and no fertilizers other than material from immediately around the beds that is incorporated into the soil. You can’t successfully switch instantly to this method of growing, because it takes time and lots of the right microbes for the soil to adapt. Charles Dowding is experimenting with this at Homeacres, his garden in Somerset. Continuous cropping is a challenging idea to those of us who came up when organics was the opposite of industrial monocropping. We championed rotations.

The author provides a list of perennial vegetables she is growing: Chinese artichokes, Jerusalem artichokes, globe artichokes, Good king henry, lovage, perennial kales, scorzonera, sea beet, sea kale, skirret, Babington leeks, potato onions, walking onions, and Welsh onions. No rotation is used for these no-dig crops, which grow with a layer of leaf litter on the soil.

Sally Morgan

Agroforestry is the practice of growing vegetables in wide alleys between trees. Sally has tried this by planting a row of cordon apples (trees trained to a single stem) along the edge of a vegetable bed. US readers should not follow her exact hedge design plan, as autumn olive, blackthorn and dog rose, for example, are invasive here.

Part 4 of the book is on boosting defenses, and how biocontrol works. This is the use of one organism to control a pest or disease. It is important to learn about the pests you have and their particular biocontrols. It’s not a case of opening the bag and throwing the stuff on!  Biocontrols have specific requirements, such as temperature or moisture. Timing is important.

Parasitic wasps, minute pirate bugs and predatory mites like Phystoseilus persimilis (which eats spider mites) can be introduced for their appropriate prey. Try to save biocontrols for when you really have a problem, and make sure you correctly identify the pest you want to control.

Predatory nematodes each have their own mutualistic bacteria living in their gut. When the predatory nematode works its way into its prey, it releases its bacteria, which kill and digest the prey. Reminds me of the Trojan Horse! The process happens below ground – nothing to see here! I found this fascinating! Nematodes need a film of water to live and move in, and temperatures above 41˚F (5˚C). Buy the right nematodes (and bacteria) for each job. This book has a two-page spread on which parasitic nematode to use for which pest. I have not seen this quality of information in any other book! Nematodes can be used to manage slugs, weevils, carrot rust fly, cutworms, onion fly, gooseberry sawfly, thrips, codling moth and more.

Plants have their own protective species. The introduction to the rhizosphere (microbiome around the roots) includes fascinating details on a type of morel mushroom that farms bacteria! Soil fungi are important for most crops, except brassicas and chenopods (beets, spinach and chard). We hear about the rhizosphere, but not the phyllosphere, the equivalent collection of micro-organisms on the leaves. This is mainly, but not only, composed of bacteria. About 10 billion on one leaf, and all different from the bacteria in the soil, and varying from one crop to another! Young leaves have mostly bacteria, mature leaves have more yeasts and senescent leaves mostly filamentous fungi. These microbes protect the plant’s health, supply biofertilizers, biostimulants and biopesticides. Some leaf bacteria suppress growth in caterpillars feeding on the leaf. Understanding this helps us appreciate the reasons for not spraying plants haphazardly with things that “might help”.

Plants have an arsenal of defenses. Thorns and hairs are just the most obvious. Some plants stockpile toxins to provide fast response to insect attack, others manufacture them as needed. When attacked, many plants respond by toughening up their cell walls in the area being attacked. Plants release various volatile compounds communicating with other plants and with insects (both the pests and predators of those pests). The example given is that when corn roots are attacked by a certain larva, the roots release a compound that attracts a nematode that is a predator of that larva. Sometimes, though, the attacker wins, as when certain beetles release their own volatile compounds in response to a plant’s compounds, signaling to other beetles to join the attack. Colorado potato beetles do this. This complexity calls our interventions into question: is it helpful to handpick the pests? Not if the pests call on comrades to join the fight.

Young sweet corn plants in July. When corn roots are attacked by a certain larva, the roots release a compound that attracts a nematode that is a predator of that larva. Photo Bridget Aleshire

If your soil is already healthy and rich in microbes, Sally thinks additions are not needed, including biostimulants, compost teas and foliar sprays to boost the numbers of beneficial bacteria and fungi. Biofungicides can prevent particular soil-borne diseases, but can’t cure them after the fact. Biofumigation is the process of growing a particular cover crop, chopping it finely and incorporating it into the oil, taking advantage of the allelopathic compounds released, to kill pests, diseases or weed seeds. Mustards, radishes and forage sorghum all have bio-fumigant properties.

The chapter on barriers, lures, traps and sprays includes recipes, and the caution that many homemade sprays kill beneficials as well as pests, as do some of the Organic commercial sprays like neem, Spinosad, quassia. Use these only as a last resort, and pay attention to dilution rates, time of day to spray and frequency of use.

Here you can find instructions for carefully treating seeds with a disease-fighting hot water treatment before planting. You can also find cautions, such as not heat-treating peas, beans, corn, cucumbers, lettuce or beets. Or old seed, as the germination rate might deteriorate too far.

Part 5 of the book is an A-Z of Pests and Disease. First are aphids – there are so many kinds of aphids! The lifecycle of aphids starts in spring with eggs hatching into wingless females that give birth via parthenogenesis to more females. Within a week, one female can produce 100 clones, which can repeat the process at the age of one week.  This continues until adverse weather or predators trigger production of a generation of winged female aphids that moves to new plants. Later in summer male aphids are born and females lay fertilized eggs that overwinter on host plants, to hatch the following spring.

Pepper plant with aphids. Photo Pam Dawling

Handpicking aphids is likely impossible, so start by blasting them off the plants with a water jet from a hose. This may decrease the population enough for natural predators to begin control. Failing this, a soap spray can be effective, although aphid predators will also be harmed. If you plant before any aphids arrive, you can use a fine mesh netting to keep them off, but monitor to make sure no aphids have got inside the net. You could try trap crops of nasturtiums to draw aphids away from your crop, but how much of your space do you want to devote to nasturtiums, and how do you deal with aphids then? The same choices of water and soap.

The list of pests continues through the alphabet. For some, nasturtiums can act as a repellent rather than a trap crop. Cucumber beetles are a good example. Nasturtiums are a brassica, and will attract cabbage caterpillars if there are no other brassicas around. There are two pages on making the garden inhospitable to slugs and snails and three pages of control options including beneficial nematodes, ducks, coffee grounds (acidic and non-specific) and iron phosphate pellets.  Finally, there are whitefly and wireworms.

The disease chapter starts with various blights, including two pages on potato blight (both types). Cankers, club root, damping off fungi, mildews, molds, rots, rusts, spots, scabs, viruses, and on with the sad list to end with wilts. It makes sense in an organizational way to end with the problems, but it makes for a sorry place to leave off.

This book is good on detailed info on soil micro-organisms and the general theme works globally. I recommend checking against local Extension Service or eOrganic before following any of the specific techniques, to ensure it’s likely to succeed where you live.

Growing Great Sweet Corn

Silver Queen sweet corn almost ready to harvest.
Photo Kathryn Simmons

I wrote about success with planting sweet corn in May. here are tips for continuing success as your corn grows!

Caring for the Sweet Corn Crop

Generally, corn needs cultivating (hoeing and weeding) at least twice, once two weeks after sowing, and once at four weeks. Even better are four cultivations: one at 7 days, a second at 14, a third around 21 days (when the plants are 6-12” (15-30cm) tall) and finally one around 35 days when they are 18-20” (45-50cm) high. We use a walk-behind tiller, and follow up with hoeing and thinning. A wheel hoe can be a useful tool. After about 30 days, corn plants get too big to get machinery between the rows.

Another good resource is ATTRA Sweet Corn: Organic Production.

At tight spacing, adequate irrigation becomes more important. Never allow soil in corn plantings to dry out. More than 1” (2.5cm) per week may be needed for maximum productivity, although corn is more drought tolerant than some crops. The most important times for watering are silking (when the silks first become visible outside the husks) and ear-filling.

There used to be a belief that it helped production to remove the suckers that came from the base of the plant. This idea has been tested, and that practice has been found to damage plants and possibly even reduce yields. (Reports from Clemson in 2002 and Colorado State in 2004).

Flame-weeding can be used after planting, pre-emergence, or, with care, after the crop is 2” (5cm) tall, using a directed flame. Consult ATTRA Flame Weeding for Vegetable Crops

Sweet corn undersown with soybeans as a cover crop. We often use soybeans as a traffic-tolerant, nitrogen-producing cover crop that also deters weeds.
Photo Kathryn Simmons

Undersowing Sweet Corn

No-till planting into strips tilled in a white clover living mulch sounds good but has been found tricky, especially during the grower’s learning curve. Jeanine Davis addresses this in NCSU’s Organic Sweet Corn Production. The clover may out-compete the corn, becoming invasive and hard to get rid of. Soil temperatures will be lower (a disadvantage in spring) and slugs and rodents may abound.

More successful is sowing a cover crop into the corn at the last cultivation, 28-35 days after emergence. We undersow with soybeans (oats and soybeans for our last planting). Although they don’t supply the highest amount of nitrogen, compared to other legumes, they are cheap, quick, somewhat shade tolerant and can withstand the foot traffic during harvesting. Other growers sow forage brassicas. Research has shown that this does not depress corn yields. The brassicas can be harvested for forage after the sweet corn harvest is finished. Undersowing with white clover is also possible.

Succession Planting of Sweet Corn

In order to have a continuous supply of sweet corn all summer, a bit of planning and record-keeping is called for so that each year’s plan can be fine-tuned. The easy and approximate method of getting a good supply is to sow more corn when the previous sowing has 3-4 leaves, or is 1-2” (2.5-5cm) tall. That will be about every two weeks. For a more even supply, sow several different varieties, with differing days to maturity, on the same date. We sow Bodacious (77 days), Kandy Korn (89 days) and Silver Queen (96 days) on the same day, and get over two weeks of harvests.

For fine-tuning for the most even supply, nothing beats real information about what happened, written at the time it happened. We have a Planting Schedule on a clipboard in the shed, and we write down actual sowing dates (next to the planned sowing date), and harvest start and finish dates. Having graphs of sowing and harvest dates for each crop has been very useful for planning effective planting dates. Use the Succession Planting method to calculate best planting dates and intervals for a continuous supply. We make six plantings: 4/26, 5/19, 6/6, 6/24, 7/7 and 7/16, to provide fresh eating every two weeks. The planting intervals are 23, 18, 18, 13, and 9 days. Because we plant three varieties, new corn comes in three times during each two weeks.

To calculate the last worthwhile sowing date, add the number of days to maturity and the length of the harvest window (7-14 days), and subtract this number from your average first frost date. For our 10/14 frost date, using an 80 day corn as an example, 80+7=87 days, brings us back to July 19 for our final sowing date. In practice, because corn matures faster in summer than in spring, this calculation gives you a little wiggle room in case the first frost is earlier than average. You could add a little more wiggle-room to be more sure. We make our last sowing on July 16.

Our sixth (and last) sweet corn planting showing our three-variety sequence. From the right: Bodacious, Kandy Korn and Silver Queen.
Photo Kathryn Simmons

Fast-Maturing Sweet Corn Varieties

Early Maturing Sh2 Varieties: The Supersweet corn varieties are where most of the attention goes these days, and bicolor is preferred. In order of maturity (speediness in ripening): Catalyst XR (bicolor, 66days); Sweetness synergistic (bicolor, 68d); Kickoff XR (bicolor, 69d); Temptress synergistic (bicolor, 70d); Xtra-Tender 2171 (bicolor, 71 d); Nicole (white, 72d); Xtra-tender 20173 (bicolor, 73d); Signature XR (bicolor, 73d); Anthem XR (bicolor, 74d); Natural Sweet Organic (bicolor, 74d); Xtra-tender  3473 (white, 75d); SS2742 (Bicolor, 75d)

Early Maturing SU Varieties: Among yellow SU cultivars, Earlivee is the earliest to mature, at 58 days, and Seneca Horizon matures in 65 days. Sugar Pearl at 73d  is the earliest white cultivar to mature. Quickie, at 64 days, Double Standard (OP, 73d) and Butter and Sugar at 73 d, are the earliest bicolor cultivars to mature.

Early Maturing SE Varieties: Among yellow SE varieties, Precocious and Spring Treat mature earliest, at 66 and 67 days, respectively. Bodacious (yellow, 75d) is well worth the wait! Of white varieties, Spring Snow, at 65 days, is the earliest to mature. There are no bicolor SE varieties.

Early maturing SE+ varieties: Sugar Buns (yellow, 70 days); Trinity (bicolor, 68d)

Remember, if you decide to grow several kinds, not to mix sh2 kinds with anything else, or everything will taste starchy.

Sweet Corn Season Extension

Transplanting can provide an earlier harvest, as already mentioned. Clear plastic mulch is sometimes used to increase soil temperature and germination rate, and to conserve moisture, producing earlier maturing corn. The plastic is spread over the seeded beds and slit when the seedlings emerge. It can be cut and removed 30 days after emergence. Weed-free seed beds are needed for this method to work organically, and plastics disposal is an issue. Rowcover is another way to warm soils (and keep birds off).

Our second sweet corn planting on July 8, a few weeks away from harvest.
Photo Pam Dawling

Pests and Diseases of Sweet Corn

Crows and other birds can be troublesome, removing the seed before it even grows. We leave the row-marking ropes in place (when hand sowing), or put some sticks and string in after machine sowing. Bird-scaring flash-tape may be even more effective. Rowcover would also work.

Some say interplanting corn with big vining squashes deters raccoons and other critters, but I think it deters crew too!

There are several caterpillar pests. An integrated organic approach to keeping pest numbers below economically damaging levels includes crop rotations, tillage, choosing resistant or tolerant varieties, encouraging beneficial insects, and ensuring adequate fertility and water. The next step is to scout for pests regularly, and take action as required.

Corn Ear Worm (CEW) is the most common pest. There may be six generations a year in the South. These caterpillars can bite – it’s just a nip, but can be a shock! A first line of defense is to choose varieties with tighter husks, which are harder for the worms to get into (Bodacious, Tuxedo, Silver Queen). Natural predators can be encouraged by planting alyssum or other small, open-flowered plants. You could buy Trichogramma wasps. The Zea-later was a tool developed for applying vegetable oil in the tip of each ear, mixed with Bt, 2-3 days past the full-brush stage of silking. Unfortunately  the treatment caused pollination problems and so it has fallen out of use. If pest numbers are not too high, you can simply cut or snap the ends off the ears.

Corn Earworm larvae come in many different colors. And they can bite!
(Photo: J. Obermeyer Purdue Extension)

European Corn Borer (ECB) drills through the whorl of leaves of the young plants, leaving a pattern of large holes as the plant develops. Bt and Spinosad will kill these, as will Trichogramma wasps. To reduce damage in future years, be sure to mow and disk old corn stalks into the soil at the first opportunity. Organically farmed soils have less of a problem with ECB.

Fall Army Worms (FAW) are also killed by Bt and Spinosad. These three pests (CEW, ECB, FAW) can be monitored in a single program, starting when the corn plants are at the whorl stage. At that point, scout for FAW, and treat if more than 15% of your plants are infested. At the pre-tassel and tassel stage scout for ECB and FAW. If infestation exceeds 15%, make a foliar spray with Bt or Spinosad. Check again in a week and repeat if needed. Then at the early silk stage, look for CEW and if needed, inject oil in the tips. If you also see ECB moths, apply Bt or Spinosad.

Cutworm can be a problem following sod, or if there are adjacent grassy areas. Bait them with bran, cornmeal or hardwood sawdust mixed with molasses and water – these baits swell inside the pests and kill them.

Corn Rootworms are best controlled by rigorous rotations.

For a more complete description of corn insect pests, see the 2004 Organic Insect Management in Sweet Corn by Ruth Hazzard & Pam Westgate. It includes good photos of the beasties. Cornell has a good Resource Guide for Organic Pest and Disease Management. Search under Crop Management Practices for Sweet Corn.  Be aware of the updated info on the pollination issues with applying oil in the ear tips, since these publications came out.

Corn Smut fungus (Ustilago maydis), known in Mexico as Huitlacoche, is edible at the stage when the galls are firm and tender. The flavor is sweetish. Silver Queen is the variety “best” at producing this fungus, should you wish to grow it. We carefully harvest the infected ears (or pieces of stem) into a special Smut Bucket, trying not to scatter the spores. Because none of us like this delicacy, we take it to the compost pile.

Young sweet corn plants in July (our fourth planting). And solar panels.
Photo Bridget Aleshire

Sweet Corn Harvest

Harvest corn before daybreak for best flavor, because the sugars manufactured in the plant the day before become concentrated during the night. We’re not that dedicated. We harvest ours in the morning, and hurry it to the walk-in cooler.

Harvest may start 18-24 days after half the ear silks show, if the weather has been reasonably warm. Judging corn’s ripeness is a skill, based on information from many of the senses. The first sign we look for is brown dead silks. If the ear has passed that test, we investigate further. All ears should look and feel plump and rounded to the tip. Each variety is a little different, so close attention is needed. Some varieties exhibit “flagging” of the ear, meaning it leans away from the stalk as it matures and gets heavier. New crew can test for ripeness by opening the side of the husk with thumb nails, and puncturing a kernel: the kernels should look filled-out and squarish, not round and pearly; the juice should be milky, not watery or doughy. The advantage of opening the side of the husks is that it is possible to close the gap if the ear is not ripe, without risk of collecting dew or rainfall. If the ear is ripe, we bend it downwards, give it a quarter-turn twist, and then pull up away from the plant.

We harvest every other day, which balances getting the amount we need with not spending more time than needed picking. Such a schedule can work well for CSA farms. Other growers could well need to harvest every day, if daily fresh corn is what your market needs. Leaving a three-day gap risks poor quality starchy ears and a lower total yield.

Take steps to keep the crop cool while harvesting. Never leave buckets of corn out in the sun. Even at room temperature, harvested OP ears lose half their sweetness in 24 hours.

After harvest, cool the corn quickly. Hydrocool if you have a large operation: drench or immerse the crop in near-freezing water. Otherwise, simply refrigerate and keep the corn cool until it reaches the consumer.

Some of this information comes from my book, Sustainable Market Farming.

Plentiful harvest of sweet corn and tomatoes.
Photo Twin Oaks Community

Dealing with weeds

 

Galinsoga- a fast-growing, fast-seeding weed of cultivated soil. Photo Wren Vile

Dealing with weeds

Why take action against weeds?

Weeds compete with crops for sunlight, water and nutrients, and can encourage fungal diseases by reducing airflow. Too-frequent cultivation to remove weeds can leave the soil more prone to erosion. Each tilling or deep hoeing stirs air into the soil and speeds combustion of organic matter. Most weeds respond well to nutrients, especially nitrogen. If you give corn too much nitrogen, even as compost, its productivity will max out and the weeds will use the remaining nutrients.

Remove weeds at their most vulnerable stage, or at the last minute before the seedpods explode —ignore weeds doing little damage.

Types of Weeds

  •   Annuals and perennials;
  • Stationary perennials (docks) and invasive perennials (Bermuda grass);
  • Cool-weather and warm-weather types;
  •  Quick-maturing and slow-maturing types;
  •   “Big Bang” types (pigweed) versus “Dribblers” (galinsoga).
Burdock is a large perennial weed with a huge root. Photo Bridget Aleshire

Sustainable Weed Management

1.      Prevent weeds from germinating

  •  Grow vigorous crops adapted to the locality,
  •  Switch between spring and summer crops in rotation,
  •  Mulch or tarp to bury short-lived weed seeds
  • Plant promptly after cultivation, so weeds don’t get the head start,
  • Transplant rather than direct sowing, giving your crop a head start on the weeds,
  • Use close spacings, leaving less space for weeds,
  • Use drip irrigation rather than sprinklers, discouraging weed germination between the rows,
  •  Plant cover crops, including no-till systems,
  • Reduce tillage whenever you can, for example, by relay planting, where the new crop is planted while the previous crop is still in place, and prevent new weed seeds coming up to the surface.
Remove weeds before they set seed. Thistle seeds blow a long way on the wind.
Photo Wren Vile

2.      Reduce weed seeding

  • Practice timely cultivation, mowing, flaming, grazing by cattle, chickens, ducks, geese. As Margaret Roach says: “No matter what weed you are facing, if it’s flowering or setting seed now, be sure to behead it: mow it down, harvest the blooms for bouquets, or otherwise prevent a successful sexual reproduction cycle.”
  • Reduce weed seed banks to 5% of original levels by preventing weeds from seeding for 5 consecutive years.
  •  Use post-emergence organic weed killers: corn gluten, vinegar, flaming
Dandelions are another perennial weed with seeds that blow and spread easily. Photo Wren Vile

3.      Reduce weed seed viability

  •  Reckon that most weed emergence happens within two years of the seeds being shed.
  •  Encourage seed-eating birds, insects, worms, mice
  •  Small, short-lived seeds of weeds with no dormancy period, such as galinsoga, will almost all die within a year or two if they are buried a few inches. Till and mulch to bury short-lived weed seeds.
  •  Longer-lived seeds (pigweed, lambsquarters, velvetleaf) if buried, may remain viable and dormant for years – Leave such weed seeds on the soil surface, rather than tilling them in! Delaying tillage if weeds have already seeded generally reduces the number of seeds added to the long-term seed bank. Seeds lying on or near the soil surface are more likely to deteriorate or become food for seed predators than buried seeds,
  •  If they do not get eaten, dry out or rot, seeds on top of the soil are more likely to germinate than buried seeds, and you can take prompt action.
  • Use stale seed-beds – prepare bed a couple of weeks before planting, water as if you had planted. The day before planting your crop, hoe the surface shallowly to kill new weeds,
  •  Solarize weedy soil in hot weather to kill weed seeds – mow the weeds, cover the soil tightly with clear plastic, weighted down or dug in round the edges. Bryan O’Hara in No-Till Intensive Vegetable Culture has popularized this technique, which makes a great use for used hoophouse plastic film. Solarizing can produce temperatures of 125˚F (50˚C) whereas temperatures under tarps (see section on perennial weeds) will be more like 110˚F (43˚C). You may need only 1-3 sunny days to kill crop residues with solarization. Cover crops and weeds may take longer to die. The heat will not go deep into the soil in that short time, and so more of the soil life will survive than with tarping.
Solarizing with clear plastic. Photo Pam Dawling

4.      Reduce the strength of perennial weed roots and rhizomes

  • Understand apical dominance: when a rhizome grows a green shoot, chemicals from that shoot prevent other nearby nodes on the same rhizome from sending up shoots.
  •  Act in a timely way – On long rhizomes, after a certain length, the dominance effect is too weak and another node can grow a shoot.
  •  Reduce the strength of perennial weed roots and rhizomes by frequent tilling or digging out.
  • Beware tilling invasive “traveling” perennial weeds once and thinking you’re done – When rhizomes are cut into pieces during tillage, the apical dominance is lost and each piece can grow a shoot of its own.
  •  Consider tarping: after tarping the plot for two summer weeks, 3-4 weeks in spring and fall, and two months or more in winter, dig out or pull up all the weed roots still alive.
  •  Next comes a counter-intuitive move (from Jesse Frost ): sow or transplant an intensive valuable crop in the areas with the worst perennial weed pressure. Of course this will motivate you to deal effectively with the weeds!
  • Pull out the pieces to dry on the surface – the depleted pieces of root or rhizome may die
  •  Or cultivate again when the new shoots have reduced the plant’s reserves (in the roots), but before they have grown enough to send energy back to the roots – it’s more effective than going almost daily after every sprig. Removing the shoots whenever the weeds reach the three- to four-leaf stage can be most effective.
  •  Late summer and fall turn out to be the best time for getting the upper hand over a wide range of common weeds, including Japanese knotweed, ragweed, Ailanthus, bindweed, curly dock and more. See Some weeds are best tackled late summer and fall Margaret Roach in A Way to Garden

Biointensive Integrated Pest Management

The weed strategies above follow the four steps of IPM: prevention, avoidance, monitoring and suppression.

1.      Prevention: Focus on restoring and enhancing natural balance and resilience to create healthy plants and soil, better able to withstand attacks. Maintain soil fertility, good drainage and soil structure; plant resistant, pest-tolerant, regionally adapted varieties; grow strong plants; practice good sanitation,

Hoe the small weeds in this bed of young lettuce soon, and the closing canopy of the lettuce will shade out most weeds after that. Photo Bridget Aleshire

2.      Avoidance: The next stage includes actions to reduce the chances of a weeds taking over. These actions are also known as physical controls. Physically remove weeds. Use good crop rotations, remove weed habitat, deter weeds. Provide habitat for weed seed predators.

3.      Monitoring:  regularly inspect your crops, find out when conditions are right for an outbreak of particular weeds. Be prepared. Identify your weeds and choose good strategies for each type. Decide when it is time to act. How to identify your weeds – online guides

4.      Suppression: When the prevention and avoidance strategies have been exhausted, control measures can be used to reduce damage of crops, while minimizing environmental risks. There are four types of sustainable bio-intensive control measures to choose from, starting with the least damaging to the wider environment:

  • a)      Biological control involves working to boost populations of existing resident weed seed predators. (For a few serious weed pests, like prickly pear, host-specific insect enemies are introduced)
  • b)      Microbial controls (bioherbicides) are plant-pathogenic fungi, bacteria, and viruses to kill weeds. Not common.
  • c)      Botanical control uses plant-based products for pest control. Examples include orange, clove and peppermint oils, and phytotoxic plant residues, such as root exudates from winter rye cover crops, and hay from sorghum, which inhibit germination of small seeds.
  • d)      Biorational controls (aka inorganic, mineral, controls) make use of manufactured products such as herbicidal soaps or strong vinegar.
Hoe weeds while they are small and you can be rid of those with short-lived seeds in a few years. Galinsoga and Outredgeous lettuce. Photo Pam Dawling

Critical weed-free period

One important factor is to observe the critical period of weed control for each crop. This is the period when crops are most affected by competition, whether from weeds, sister seedlings or those of an intercrop. Seedlings suffer more than transplants from being out-shaded. Transplants are soon past their critical weed-free period, perhaps half of it before you even set them out. As well as the critical period, take note of the severity of drop in yield for the particular crop. A lot of the information below comes from The Living Soil Handbook by Jesse Frost, which I had the pleasure of reviewing recently.

  • Small salad crops like arugula, spinach and baby lettuce mix, really need to be weed-free throughout their growth. Apart from the risk of being smothered and producing poorly, there is the risk of including bits of recognizable weeds in your salads.
  • Bulb onions also benefit from being weed-free throughout growth. Like other narrow-leaved plants, they are poor competitors. Carrots also are very poor competitors – for most of us, the over-abundance of carrot seedlings in the row are as much of a threat as the weeds. Parsnips are similar, with the added challenge that they are slow to emerge.
  • Peas do best with no competition, although, because they grow vertically, they can do OK with a companion crop such as spinach (or weeds!) a short distance away.
    Hilling potatoes before the weeds get too big will deal with the weeds as well as giving the potatoes more growing space. Photo Wren Vile

    Potatoes, weeds and standing water. Until the soil drains, the potatoes cannot be hilled, and the weeds here are already large. The yield will be reduced by weeds competing with the potatoes.  Photo Bridget Aleshire
  • Potatoes need 1-8 weeks after emergence free from weeds, although small weeds are not a problem and the process of hilling potatoes (needed to provide growing space) effectively deals with weeds.
  • Beets need 2-3 weeks after emergence weed-free from direct-sowing. My experience is that beets are their own worst enemy, and the clusters of seedlings that emerge from each seed-ball should be singled as soon as possible. Yields can easily drop 1-5% with small-average weeds. Turnips also need to be competition-free for the first few weeks after emergence.
  • Broccoli, cabbage, cauliflower, collards, kale and most Asian greens need 2-3 weeks after transplanting free of weeds.
  • Sweet potatoes need 2-6 weeks free of competition after planting. Because it gets hard to wade in and pull weeds later, we try to keep them weed-free.
Garlic beds under a stormy sky. Keep alliums free of weeds.
Photo Wren Vile
  • Garlic needs 3-7 weeks from emergence free of weeds. If you plant in the fall, start counting in early spring when weeds start to grow again. Like most alliums, the narrow vertical leaves make it a weak competitor.
  • Basil, cucumbers, squash, zucchini, lettuce and many other crops need four weeks from transplanting free of weeds. Be careful not to damage squash roots when removing weeds.
  •  Tomatoes need 5-6 weeks after transplanting free from competition, although they are fairly strong competitors later, and we routinely transplant our hoophouse tomatoes down the center of a bed of salad greens, progressively harvesting the greens over the next month. We have noticed problems only if we leave other crops too close for too long. Always prioritize the well-being of the new crop!
  • Peppers need 5-10 weeks after transplanting free from competition, although the drop in yield is small (5%)
  •  Fava beans need four weeks from emergence free of weeds
  •  Direct sown kale needs 6 weeks from emergence weed-free.
  • Okra requires 6-8 weeks after sowing weed-free. If you transplant okra as we do, half that period will be over by transplanting date.
  • Beans are a crop that can generally out-compete weeds (losing only 3% yield from competition), but keeping the rows clean until the beans flower (about 6 weeks from sowing) will maximize yields.
  • Corn needs about 7 weeks from seeding free of weeds (until there are 6 leaves).
  • Eggplant calls for 8 weeks from transplanting free of competition.
  •  Leeks, another weakly competitive allium, need 12 weeks post emergence weed-free. If, like us, you transplant leeks at about 10 weeks after sowing, this translates to hoeing the beds of transplanted leeks a couple of weeks of transplanting.

Flameweeding

I won’t say more about this here. Click the link to read previous posts.

Mulches

Mulches are a big asset in weed control. Organic mulches also add biomass to the soil. Remember not to use organic mulches around warm weather crops for their first month, as they need warm soil to grow well, and insulating mulches keep the soil cold.

See our experience with Biodegradable plastic mulch

Read Organic Farming Has A Plastic Problem. One Solution Is Controversial about the controversy surrounding biodegradable plastic in Organic Farming

Cover crops

Summer cover crops smother emerging weeds, prevent weed seed germination, between a spring food crop and a summer or fall one. Winter cover crops smother emerging winter annual weeds. Good cover crops for this purpose: sorghum-sudangrass, pearl millet, winter rye, wheat, barley, oats, buckwheat, brassicas (beware – rotation, bugs), lupins, red clover, subterranean clover, berseem clover, soybeans, cowpeas.

Ida Gold mustard (Sinapis alba) contains a gluscosinolate, ‘sinalbin’, a non-volatile compound that has shown the ability to inhibit weed seed germination. Tillage radish has a similar effect. The cover crop needs to be mowed and tilled in. Solarization after incorporating mustard is known as biofumigation.

Cover crops also improve the soil for crop production.

Iron and Clay southern peas as cover crop in the hoophouse, smothering weeds.
Photo Pam Dawling