I just got back from the Virginia Association for Biological Farming conference in Roanoke. There I gave a half-day presentation on Year-Round Hoophouse Vegetables, which you can watch here:
The conference was very well-attended, and not everyone at my workshop on Friday, or the Alliums Year-Round 90 minute workshop on Sunday morning got a handout. I promised to post them here, and now I’m making good. I’m also posting the handout for the third workshop I gave, Asian Greens in the Winter Hoophouse. This rounds out the set, and gives a chance to those who went to a different workshop at that time to get a look in.
The 23rd annualVirginia Biological Farming Conference is Virginia’s premier organic and sustainable agricultural conference! The Conference brings together farmers, gardeners, eaters, educators and advocates of biological and organic farming and gardening. The Conference will be held in person January 6-8, 2023 at The Hotel Roanoke and Conference Center.
The three-day Conference includes: Full and Half Day Pre-Conference intensive workshops, 50+ sessions and workshops, presentations and panel discussions, 40+ tradeshow exhibitors, locally sourced farm meals and book signings. The Conference features a Silent Auction and networking opportunities including regional networking meetings, and the Taste of Virginia Expo & Social!
Keynote Speakers
Dr. Elaine Ingham, Soil Food Web School
Leah Penniman, Founding Co-director Soul Fire Farm
I will be presenting a half-day workshop 8am-noon on Friday Jan 6, on Year-Round Hoophouse Vegetables
90 minute workshop Sunday January 8, 8.30 am – 10 am Alliums Year Round
90 minute workshopSunday January 8, 10.30 am – noon, Asian Greens in the Winter Hoophouse
Included in the Conference Registration and free and open to the public is the Taste of Virginia Expo & Market on Saturday, January 7, 2 – 9 PM in the Crystal Ballroom at Hotel Roanoke. Featuring sampling and sales of Virginia-crafted foods, local libations, handicrafts, and herbals. Complete the evening with music, dancing, and socializing from 8-10 PM.
Locally Sourced Meals
VABF and LEAP Local Food Hub are working together to procure the majority of our Conference food from local member farms. We look forward to supporting our member farms and enjoying delicious, fresh, local food from the farms below! All Conference Registrations include lunch and dinner on Saturday, lunch on Sunday and morning coffee and tea.
The Conference will be held at Worcester State University on Saturday January 14 and online Sunday January 15. We encourage you to make the most of the range of possibilities – i.e. tastings in person, international discussions over Zoom, tool modifications, storytelling. Creativity is welcome!
An organic lunch on Saturday is sandwiched by over 40 educational workshops for a full day of learning and socializing.
This is a valuable opportunity for farmers, gardeners, homesteaders, educators, and environmentalists to share resources and ideas to grow our vibrant organic community. We are excited to come together around this winter’s theme, “Cooperative Foodways: Building Our Future Together.”
The conference hosts 40+ workshops and draws hundreds of attendees from throughout the Northeast.
I will be giving a workshop on Crop Planning for Sustainable Vegetable Production
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Cold damage update
Bright Lights chard with cold-damaged stems. Dec 27. Pam Dawling
I reported very little damage to our hoophouse crops last week when it was 2F (-17C) outdoors. Since then, no plants keeled over, but some leaves are showing tan patches of dead cells, either where the leaves touched the rowcover. or where they were not properly covered. So, we have lost some leaves of senposai, a few of spinach, some on the yarrow we planted for beneficial insects. But, overall, I’m extremely happy with the good condition of our crops.
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Mistake about potato yields
Sorting potatoes two weeks after harvest to remove problem potatoes before rot spreads. Photo Wren Vile
Yes made a mistake back in 2012, when I wrote Sustainable Market Farming, which I hope has been corrected in reprints since I was first notified of this in August 2019. If you have an older edition of my book, it might still have the error. In yield numbers on page 376, it says about potatoes, “Yields are likely to be 150 lbs/ac (168 kg/ha); 200 lbs/ac (224 kg/ha) is a good yield”.
“Yes, my mistake indeed! On page 45, I have the (better!) info that potatoes can yield at least 110 pounds/100 feet, or 49.9 kg/30m. I think I probably meant to write on page 376, that a low yield could be 150 pounds/100ft, which is equivalent to 11 tons/acre. In the metric system, that’s 223 kg/100m, or 24.4 tons/ha. Other sources suggest average yields could be almost twice this. And good yields, even 4 times the low numbers.
So it should say
“Yields are likely to be 11 tons/ac (24.4 tons/ha); 22 tons/ac (48.8 tons/ha) is a good yield”
That’s US tons of 2000 pounds, metric tons of 1000 kg. Or for a smaller scale, probably closer to what most of us are growing,
“Yields are likely to be 150 lbs/100ft (223 kg/100m); 200 lbs/100 ft (300 kg/100m) is a good yield”
Our hoophouse beds after the nights at 2F (-17C) and 8F (-13C). Looking amazing! Pam Dawling
We were luckier with the weather than many people over the weekend (12/23-12/26/2022). And so were our vegetable crops. On Friday 12/23 we prepared for a suddenly very cold night. It was very windy as we battled to stop the hoophouse windows from blowing open. We finally got some shims, a hammer and a stepladder, and wedged them closed. They stayed that way until Tuesday 12/27. We were fortunate in getting no precipitation (I hate ice!) and no power outage.
Pool noodles repurposed as draft excluders. Pam Dawling
We fortified the doors with our rock collecting buckets, and prevented most of the under-door drafts with our pool noodle draft excluders. They have a rope running through them, which is hooked onto small cup-hooks on the door frame. We repurposed noodles that had been used as props at a party or some other kind of event. They had been covered in tube socks and had glued-on googly eyes.
Rolls of rowcover at the ready in our hoophouse. Pam Dawling
It was a bit unnerving being in the hoophouse as it creaked and groaned in the wind. In the winter we keep rolls of rowcover ready for any night we think will be below 8F (-13C). We unrolled the rowcovers by lunchtime and laid tools on the ends nearest the doors. I was worried that if we lost power, and therefore the inflation, it would get very cold indeed in the hoophouse.
The DIY manometer in our hoophouse. (the background lines have faded). Pam Dawling
Since we last changed the plastic we haven’t managed to get the recommended 1/3” (8.5mm) pressure difference in the “bubble” between the plastic layers, compared to our normal air pressure. Mostly we don’t even get ¼” (6.5mm). The “bubble” provides thermal insulation as well as physical strength against snow or ice buildup, and strong winds.
It got down to 2F (-17C) outdoors Friday night, and Saturday didn’t warm up much. I don’t actually know what the night temperature was in the hoophouse as our recorded low temperatures don’t make sense: 14F (-10C) for four consecutive nights (Fri to Mon). I suspect we didn’t reset the thermometer correctly. Usually the hoophouse can hold 8 F (4.5 C) degrees warmer than outdoors, but not 12 F (7 C). It looks like it did, perhaps because we didn’t open it all day!
Soil thermometer in our hoophouse on 27 December 2022. Pam Dawling
The soil is still nice and warm in there: 59F (15C). That really helps. The rowcovers are usually removed in the daytime, either pulled aside if we expect to need them again the next night, or rolled up out of the way. Most of the time they stay rolled up at the east end of the hoophouse. We appreciate not needing to deal with rowcovers most of the time! On Saturday 24th, the temperature maximum for the day outdoors was 24F (-4.5C), and we kept the rowcovers in place over the crops. On Sunday the high outdoors was 28F (-2C) so we pulled the rowcovers aside until the night. On Monday 26th the night-time forecast was benign enough that we rolled the rowcovers up. And now we get a milder spell.
Hakurei turnips with frozen yellow leaves where they touched the plastic (rowcover protected the plants). Pam Dawling
How did the crops fare? It’s not always obvious at first if a crop has been killed by cold or not, But I can now say with confidence that nothing died. The edge beds are always the coldest. The south edge bed had Hakurei turnips, delicious and notoriously the least cold-hardy turnip variety. Most of the globe of the turnip sits on the surface of the soil. You can see in the photo that some of the leaves, the ones right by the wall plastic, have been killed and turned yellow. But the roots themselves (with rowcover over them) seem fine.
Bright Lights chard with cold-damaged stems in our hoophouse north edge bed after nights at 2F and 8F Pam Dawling
Over the other side, in the north bed, we have some Bright Lights chard, among other things. Multi-colored chards are less cold-hardy than red ones, which in turn are less cold-hardy than green ones. We know we take a risk in growing Bright Lights through the winter, but we so enjoy the sight of the short pieces of colored stems in our salad mixes that we take the risk. Some of the stems have curled over, probably on their way to dying, but the plants live on, to provide many more salads this winter! And some cooked greens too.
Some of the giant senposai leaves, where not fully protected by the relatively narrow rowcover, have developed tan dead spots, so those leaves can just continue as the plants’ solar panels until we get tired of looking at them and decide they are no longer needed.
Each winter I update my Winter-Kill Temperatures of Cold-Hardy Vegetables list, except this past spring I had nothing new to add. Outdoors, I noticed today that the tatsoi has definitely died, the Vates kale and the spinach have survived (uncovered) and the small garlic leaves don’t seem troubled. The leftover lettuce transplants have been damaged, if not killed.
We are feasting on our winter salad mixes now, so I decided to write a post to encourage more people to grow winter salads.
Just how viable this is for you depends on your winter climate zone and your facilities. In the coldest of places with nowhere except your kitchen or a windowsill, you can grow sprouts and microgreens.
To grow sprouts, get some organic seeds, soak them in a jar, then fit a straining lid, which can simply be a piece of fabric held in place over the open mouth of the jar with a strong rubber band, or, if using a Mason jar, the metal ring part of the lid. Drain off the extra water, then set the jar on its side, with the seeds distributed evenly along the side. Rinse and drain twice a day, until the sprouts are the size you want. Here’s a couple of websites.
You don’t need to follow these directions word by word, but if you do, it will work. Other methods can also work. Just be sure to rinse and to drain!
The enthusiastic author of How to Grow Microgreens, Sylvia Fountaine, lays out a 6-step process and provides a video. Microgreens are basically seedlings, with stems and green seed leaves. Sprouts are mostly root and stem, as you may have noticed.
I wrote about our Fall Lettuce Transition in my post Preparing your Hoophouse for Fall and Winter 9/28/22 – This post includes days to germination of lettuce at various soil temperatures. Here are dates when we sow lettuce for growing in various places (not just our hoophouse).
·For outdoor lettuce I stop sowing August 29, transplant those 9/22 and expect to harvest them 12/10 – 12/31. I add hoops and thick rowcover when it gets cold to keep it growing.
Buttercrunch Bibb lettuce in December. Photo Kathleen Slattery
·For winter growing in coldframes, I sow 9/1, 9/3, 9/5, 9/7, 9/9 and transplant 9/25 -10/8. Leaves from those plants can be harvested all winter until we need the cold frames to harden off spring transplants in mid-late February. We cover the coldframes with rowcover when it starts to get cold, then plastic-glazed lids as it gets colder, and quilts for really cold spells. These days we are more likely to direct sow spinach in the frames than transplant lettuce. It’s hardier and faster growing.
·From September 11-17 we sow lettuce every other day in our outdoor nursery bed, to transplant in our unheated greenhouse (double glass windows, solid north wall, rarely freezes in there). We harvest those lettuces by the leaf all winter until we need to dig out the compost they are growing in to fill our seed flats in early February.
Lettuce growing in our greenhouse in November. Photo Wren Vile
·On September 15 and 24 we sow lettuce outdoors in a nursery bed, to transplant in our hoophouse10/15 and 10/24. Those lettuces will feed us all winter, 11/16-3/1, if we simply harvest the outer leaves, rather than cut the head.
Green Panisse and red Revolution lettuce in our hoophouse in November. Photo Pam Dawling
·On October 23 we start sowing lettuce mix in the hoophouse. We sow successions of baby lettuce mix directly in the soil 10/24, 12/31, 2/1, 2/15. The last one, on 15 February, will be for harvest starting mid-March, and ending in May when it gets too hot. By then we should be happily harvesting juicy lettuce heads outdoors and will have lost interest in the lettuce mix.We like Fedco’s 2981LO Lettuce Mix OG or Johnny’s Allstar Gourmet Lettuce Mix #2301. For those with challenging growing conditions, both companies offer other specialized selected mixes. 1 oz (28gm) of seed sows about 600 ft, (200m)
Baby lettuce mix in our hoophouse in winter. Photo Twin Oaks Community
·We sow “filler leaf lettuces” in our hoophouse 10/23, and 11/9, to use for gap filling (replacing casualties). 1/25 is our last date for filling any gaps in the hoophouse beds with lettuce plants. After that, we fill all gaps with spinach plants.
Short rows of filler greens in the north edge bed of our hoophouse in December. Photo Kathleen Slattery
·So, we have different “stop-dates” for the different types and locations, but no complete Lettuce Stop-date.
o8/29 Last date for sowing for outdoor row-covered lettuce
o9/9 last date for sowing to transplant in coldframes
o9/21 last date for sowing for planting in an unheated greenhouse.
o9/24 last date for sowing for planting into a double-layered hoophouse
o11/9 last date for sowing “filler leaf lettuces”
o2/15 last date for sowing baby lettuce mix in the hoophouse.
How should people not in central Virginia calculate their own stop dates? Using the same numbers as above for the various types and locations:
Figure out how late in the year it’s worth having lettuces outdoors. When does the temperature drop to 20°F (-7°C)? Stop sowing for outdoors 3-4 months before then. (Our 8/29 sowing is harvested by 12/31, but our 8/20 sowing is harvested by 11/25). It’s worth experimenting to find which date works best. Outdoors, I have found that lettuce may survive an occasional dip to 10°F (-12°C) with good rowcover. Consult your Extension Service and the website WeatherSpark.com. Fill in your location and look at pages of useful info about the weather where you are.
Figure when yourcoldframes get down to say 15°F (-9°C). This might be when the outdoor night-time low is 10°F (-12°C), lower if you have a well-insulated coldframe. We have some old quilts to roll on top of our coldframe on nights below 15°F (-9°C). Perhaps lettuce won’t make it all the way through winter in a coldframe in your climate. If so, be prepared to clear the plants when it gets too cold. Calculate back to figure when to sow – allow 4 months to get full sized lettuces.
Figure when your solar double-paned-glass and masonry wall greenhouse gets down to ° (-9°C), or add a small heater with a thermostat to keep it warmer than that. Calculate back to the sowing date, allowing for the fact that plants grow quicker in a greenhouse than outdoors or in coldframes. Maybe allow 3 months.
Our greenhouse with young lettuce transplants in early October. Photo Bridget Aleshire
As far as daylight goes, on 9/24 everyone everywhere is pretty much getting the same amount wherever we live. With a hoophouse, the goal is to grow plants to harvestable size by the time you no longer have lettuce from outdoors (refer to #1). It probably only takes 2 months to grow a lettuce big enough for leaf harvest in a double layer hoophouse. Just be sure not to over-harvest in the winter. We have had lettuce survive a double layer hoophouse temperature of 10.4°F (-12°C) without any rowcover (sometimes called an inner tunnel), and -2.2°F (-19°C) with.
At this point calculations switch to what happens after the Winter Solstice. When do you plan to start harvesting your first outdoor lettuce again? Aim for a two-week overlap with both hoophouse and outdoor lettuce available in the spring. Work back from your hoophouse harvest end date to find the last worthwhile sowing date for filler lettuces. Because lettuce bolts easily when it gets warm in spring, play it cautious. We plan to start outdoors 4/15. We stop transplanting lettuce in the hoophouse 1/25, 2 1/2 months before then. Sowing filler lettuce too late is not really a problem – you can cut it as baby lettuce. But avoid transplanting it just to have it bolt.
If your climate is cold, or you don’t mind only getting one or two cuts from baby lettuce mix, you can carry on sowing it until the soil temperature reaches 86°F/30°C (max temp for lettuce germination). If it is warm, do be sure to water often, so the lettuce doesn’t turn bitter. Otherwise look to you first outdoor lettuce and clear the baby mix when the outdoor crop is ready.
Beautiful baby lettuce mix in our hoophouse in February. Photo Wren Vile
See my post Lettuce All Year in a Changing Climate 8/31/21. It includes links to all my Lettuce of the Month series, and includes my slideshow Lettuce Year Round and our 2022 Lettuce Varieties List, to help you choose varieties we recommend for different times of year.
For ideas on mixing various crops in winter salads, see Making Salad Mix 10/31/17 and Fast Growing Vegetables3/24/20. Winter salad mix is also known as mesclun or spring mix (even though we are growing it in the winter). Spinach and many brassicas grow faster than lettuce in cold weather, and make delicious salads.
Bulls Blood Beet leaves Photo Bridget Aleshire
Also, check my Asian Greens of the Month posts. This post from April 2018, includes at the end links to each of the series. Many Asian Greens make great salad crops. The frilly mustards featured in this post are a good example.
For information on the temperatures that many crops will die at from cold, see Winter Kill Temperatures2021. I was updating this list each spring. 2022 seems to have slipped by. I don’t think I had any new information, as the winter wasn’t extreme (although we had a long and memorable power outage!).
I missed Giving Tuesday, but I do have a donation button for anyone who is able to support my work! I appreciate the help, as blogposts don’t exactly pay for themselves.
September-sown Borage flowering in our hoophouse in January. Photo Pam Dawling
It’s late November as I write this. Starting last fall (2021) we sowed a range of flowers to attract beneficial insects, to plant in our hoophouse in hopes of reducing the early spring aphids. 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. In January we get bad aphids on the lettuce and, of the flowers we planted 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. We also 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.
Young eggplant struggling against lots of aphids. Photo Pam Dawling
Most flowers in our trials were annuals, and they flowered and died. We still have four yarrow plants and one bushy shungiku. Shungiku is Glebionis coronaria, (formerly called Chrysanthemum coronarium, Ismelia coronaria, Xanmthophthalmum coronarium, or Pinardia coronaria), and commonly called Crown Daisy. Most chrysanthemums are perennial with poisonous leaves, but shungiku is an annual. Our plant seems not to know this.
September-sown shungiku (chrysanthemum greens) in January. Photo Pam Dawling
Shungiku is the eastern Japanese name for the edible chrysanthemum, also known as “garland chrysanthemum” or “chop suey greens” in English. It is known as “Kikuna” in western Japan, “tong hao” in Chinese, ssukgat in Korean and cải cúc or tần ô in Vietnamese. There are various colors of flowers. Ours are yellow, not banded with other colors. We bought seed from Small House Farm. Bevin Cohen says it does attract bees, butterflies and predatory insects, and would probably do well in the winter hoophouse, and could be provoked into bolting early in the spring.
After our research and trials, we decided it isn’t worthwhile growing the annuals, as they didn’t flower when we needed them (except this shungiku!). We might try borage again, as it was quick to flower last year, and other people have done well with borage. Ours died. We also decided (as recommended by a reader) to leave some overwintered brassicas to flower. We are starting to find bolting mizuna, so that may be perfect.
Bolting mizuna in our hoophouse Photo Pam Dawling
Two of the four yarrow plants have flowers (in November) and we will keep them. Having perennials seems a good way to get flowers in early spring. These plants were too young to flower last spring. We still have some seeds of the perennial phacelia, so we could try that again, although perhaps it isn’t cold-hardy enough.
Anti-aphid yarrow flowering in our hoophouse in late November, 13 months after sowing. Photo Pam Dawling
If you want to read the trials and research that led us to this point, see two posts from February 2022: More on Insectary Flowers. It was too cold for predators in early February, even with enticing flowers. Ladybugs showed up in late February and we had borage flowers for them, but no other flowers. We had sowed at the very beginning of September and the very end of October. After that, we started more flowers in our greenhouse on February 1. We noticed that plants in pots dry out very fast in the hoophouse, and they have to be hand-watered, as the drip tape doesn’t do it. It’s probably better to get the flowers in the ground in the hoophouse and greenhouse as soon as they are big enough.
I listed aphid predatory insects such as ladybugs, lacewings, aphid parasites, damsel bugs, braconid wasps, rove beetles, syrphid flies, and spined soldier beetles, as are attracted to plants with small flat open flowers, like alyssum, dill, yarrow, buckwheat, sunflowers, and cosmos.
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.
A ladybug on the leaf stem of a sunflower planted to attract beneficials. Photo Pam Dawling
Organic Integrated Pest Management involves tackling pest problems one step at a time with ecologically-based practices, starting with actions chosen to reduce the chances of the pest ever getting a grip on your crops. You can find various listings of steps online and in print. They are all in basic agreement – start with prevention, follow with avoidance, and finish with pest-killing if needed. I recommend the ATTRA Organic IPM Field Guide. Each of the 22 pages is a poster, complete with good photos and concise clear info.
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.
A pepper leaf with tiny aphids. photo Pam Dawling
That post describes the lifecycle of aphids, starting 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.
There is a chart in the post, giving details of the flowers we chose, where we found the seed, and which months we decided to plant them in.
Our first sowing, in September, was of borage and shungiku (Chrysanthemum greens) only. We thought having some flowering plants in large pots would enable us to move them to the trouble spots, but plants in pots dry out too fast. The borage flowered with pompom-like clusters, much more compact than spring outdoor borage does.
Anti-aphid flowers yarrow in pots in January (October sown) Photo Pam Dawling
The second sowing, in late October, included Meadowfoam, Tidy Tips, Phacelia and Yarrow. Those plants were still small at the beginning of February. No flowers, no help against January lettuce aphids.
The third sowing was February 1, and included borage, shungiku, Meadowfoam, Phacelia, Tidy Tips and yarrow.
The September-sown borage and shungiku both had trouble with cold temperatures during January – three non-consecutive nights at 10F (-12C). Some of each got cold-damaged.
By February, no beneficial insects had been seen on the borage flowers, and no aphids had been killed as a result.
Shungiku in November with a bee. Pam DawlingShungiku with spider, in November. Pam DawlingShungiku with a fly in November. Pam DawlingThis looks like a leaf-footed bug on the shungiku in November. Not good news to have this pest around! Pam Dawling
Climate change is making the problem worse: for every 1degree Celsius rise in average temperature (about 2 F degrees), aphids become active two weeks earlier.
Organic Integrated Pest Management
I have a blog post about our organic integrated pest management, a 7 step method of pest management which starts with actions least harmful to the ecosystem, only employing biological controls such as botanical sprays and selective pesticides if necessary after all other steps have been insufficient.
Pepper plant with aphids and ants farming them. Photo Pam Dawling
Applying these principles to dealing with early spring aphids
Prevent infestation Control ants (which farm aphids for their sweet excretions). Try repellents, or trap crops of nasturtiums.
Cover or protect physically with fine mesh netting.
Provide habitat for natural enemies. Plant for a continuous supply of insect-attracting blooms, that flower early in the year and attract predators such as ladybugs, lacewings, syrphid flies (hoverflies), damsel bugs, big-eyed bugs, and spiders. Grow early flowers with pollen and nectar they can use as alternative foods. Sow seed in fall for earliest bloom.
Monitor crops at least once a week
Introduce natural enemies: We do have an aphid parasite in the hoophouse as we do find mummies, but not enough to control an aphid outbreak in spring. Parasitic wasps for aphids include Aphidus colemani from Arbico Organics; Aphidus ervi from Arbico; a predatory gall-midge, Aphidoletes aphidomyza, (cost $125 including shipping per week, perhaps $375 total); Green Lacewings (more affordable); Ladybugs, notorious for flying away.
Hand pick and kill. Handpicking aphids is likely impossible, so blast them off the plants with a water jet from a hose.
Use biological controls. Failing success with the methods above, a soap spray can be effective, although aphid predators will also be harmed. We use 3 Tablespoons (15 ml) per gallon (3.8 l) of biodegradable Murphy’s Oil Soap, in a sequence of 3 sprayings 5 days apart.
Also see that post for details about Tidy Tips (Layia platyglossa), a spring flowering wild annual in the aster (sunflower) family; Meadowfoam (Limnanthes douglasii), a fast-growing bushy annual commonly known as poached egg plant and Douglas’ Meadowfoam; Baby blue eyes (Nemophila menziesii), a low spreading, shrub-like annual; Borage, a warm-season annual, taking only about 8 weeks to flower from sowing; Sweet Alyssum, a small annual; Shungiku, described above. We considered, but did not plant two biennials: Dill and Angelica, as they sound quite large. The perennials we chose, are also large (30” tall, or much more, and might need staking), but the advantages of having permanent working plants won us over. Yarrow is hardy to zone 5. Common Yarrow (with flowers that range from white to red) is hardy down to zone 3. It attracts an array of beneficial insects. Phacelia is particularly useful in early spring if it has overwintered as it is an early pollen source for bees coming out of hibernation. Sow in the fall for early spring blooms But it winter-kills at approximately 18˚F (-8˚C), and I think that’s what happened to ours. We also considered Fennel,Foeniculum vulgare (common fennel) but it blooms from mid-summer to frost. Too late and too tall for our goal of attracting spring aphid predators in the hoophouse. Coyote bush, (Baccharis pilularis), also called chaparral broom, is a native shrub related to sunflowers, that sounds way too much of a space hog. And Dandelions – I just couldn’t bring myself to risk planted this sturdy weed in the hoophouse!
That post also includes details of natural enemies you can buy, and how to make a soap spray if none of those efforts work. Also there you will find the approach we decided on as the Best Options for our Hoophouse and Greenhouse in April and May
November photo of shungiku flowering in our hoophouse alongside Yukina Savoy, senposai and Hakurei turnips. Pam Dawling
This post covers insectary flowers 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.
flowers in our outdoor Insectary Circles in the vegetable garden to attract pollinators and pest predators. We use circles cut from plastic buckets to surround these clusters of flowers so that inexperienced helpers don’t pull them out as weeds. We use a combination of sunflowers, dill, borage, cosmos, calendula, tithonia (Mexican sunflowers), zinnias.
Cindy Conner suggested leaving parsley and celery plants to overwinter and flower early.
A willow tree behind out herb garden. Photo Bridget Aleshire
“The willow which bends to the tempest, often escapes better than the oak which resists it.” Sir Walter Scott
I’m reading Laura Lengnick’s book Resilient Agriculture, (review coming soon) and thinking about how growers thrive under varying situations, some of which we have no control over. To adjust to changing weather conditions, to continue after challenges and get the best possible outcome whatever happens, we need to be alert, adaptable and quick on our feet, a bit like a Ju-Jitsu practitioner.
Being ready to tackle whatever happens includes recognizing and building in many options, keeping all options open until the future is clearer, and knowing when and which way to jump. It involves being prepared with needed equipment (or at least phone numbers), and having our filing systems be accessible all year, not in a big heap!
It includes getting good at understanding current conditions and predicting the future, getting to grips with radar maps and how to use Growing Degree Days. It involves keeping records of when certain flowers bloom (phenology), and soil temperatures. This information helps us figure out when to plant according to actual conditions, rather than simply by the calendar, a method which is not useful as climate change takes hold.
A honeybee on deadnettle weeds. Fall deadnettle germination shows that conditions are cool enough to sow spinach. Photo Kathryn Simmons
Making good assessments of conditions is the first step in cultivating adaptability. The second necessary skill-set is the ability to know how to make a swift and effective decision and locate the resources to put that decision into practice. This includes information about soil temperatures and how long various crops take to emerge. Also, knowing how summer crops will respond to extra high temperatures. And how winter crops will respond to horrifying low temperatures. When is it time to cut your losses on a struggling crop and till it in? I do a weekly tour of the gardens and re-prioritize tasks. Growing food is an organic process, non-linear!
These two skills are followed by a review process, so we can learn from what went wrong, as well as what went right! Usually this involves record-keeping, (dates, actions and results) to inform next season. You can list other possible responses to fine-tune your choices next time. Record-keeping can include photos, audio recording, video clips. Whatever works. You may only need to tweak your response in future, or you may want a completely different approach. One of our garden mantras is “Never repeat the same mistake two years running.”
Get Ready for Farming After Anything
Carol Deppe in The Resilient Gardener: Food Production and Self-Reliance in Uncertain Times recommends building in slack, rather than planning to work flat out every day. When something unexpected happens, you’ll have a bit of extra time available to tackle the problem. Personal troubles like injury, health challenges, or family emergencies; or household events like financial problems can require time focused elsewhere; or disastrous weather that affects everyone around you. On her website, Carol has an interview called Food in Uncertain Times: How to Grow and Store the Five Crops You Need to Survive.She says: “The resilient garden is designed and managed so that when things go wrong, they have less impact.” Grow food requiring minimal external inputs, know how to grow staple crops and save seeds. Some years you won’t need to employ these skills, but you’ll be ready when you do.
Being Flexible About Growing Food
Our kale beds after heavy rain. Photo Wren Vile
We have a Garden Shift Honchos Guide to help whoever is leading the crew. It includes general guidelines: “Try to at least get the harvesting done, whatever the weather, (unless torrential rain, tornado, ice storm, thunder and lightning).” It suggests how to choose jobs from our posted task list. My priority sequence is harvest, plant, mulch, prepare beds for planting, hoe, hand weed. The Honchos Guide has hints for contingencies:
If the day is likely to be very hot, get the physically taxing tasks done first (especially anything involving shovels).
If the morning starts out with a heavy dew, postpone harvesting cucurbits, nightshades, strawberries and legumes until the leaves dry, to reduce the spread of disease.
After heavy rain: mulched perennials (fruit and asparagus) are the easiest places to work. Don’t work in sinking mud, it compacts the soil, which means the plants go short on air, and the soil will be slower to drain after future rains. Standing on long boards is an option for harvesting or planting.
If heavy rain is expected and you might have to stop in a hurry, do weeding, not planting. It’s a waste of time to hoe if it’s about to rain, or that crop is due for overhead irrigation. Don’t leave pulled weeds on the beds before rain or irrigation. They’ll re-root.
If you feel frazzled: choose a big simple task lots of people can do, like weeding strawberries, or hoeing corn. Or choose two tasks geographically close, so it’s easy to keep an eye on everything happening.
Choreographing the crew can be hard. It’s handy if everyone finishes harvesting around the same time. Perhaps spread out at first for miscellaneous harvesting, and then end up together on the crop that takes a long time.
Building in Options on the Farm
Stewart Brand in How Buildings Learn: What Happens After They’re Built, advocates for constructing buildings that are easy to modify later, in gradual or drastic ways to meet the changing needs of the people inside. Farms can be looked at similarly. Keep as many options as possible (for crops, cover crops, crop layout) open for as long as possible.
It can be helpful to do some scenario planning, which I learned about in The Art of the Long View, by Peter Schwartz. Scenario Planning is a method of making flexible long-term plans, using stories (scenarios) to help us visualize different possible futures that include not only factors we don’t control, like the weather or the market’s enthusiasm for bulb fennel, but also intangibles such as our hopes and fears, beliefs and dreams. Different combinations of uncertainties and possibilities, including interactions of some major variables in plausible but uncomfortable as well as hoped-for combinations are used to create each scenario.
Sometimes the easiest way to compare scenarios is to set options out in a grid. For instance, in choosing which cover crop to sow following a spring crop that we clear in August-October in zone 7, we can say that the main variables are whether the season is dry or wet, and whether we are early or late planting. We can sow oats from mid-August to early September, to winter-kill, or winter rye once we reach September 1 (before that we risk the rye heading up before winter and self-seeding).
Dry and Early: Sow cowpeas or soybeans with oats, for a winter-killed cover crop.
Dry and Late: Sow winter rye or wheat alone.
Wet and Early: Sow a clover mix in August, or hairy vetch with winter rye, 9/1-10/10
Wet and Late: Sow Austrian winter peas with winter rye
Often there are more variables, such as weediness. We might undersow our fall broccoli with a clover mix in August, intending the clovers to become a Green Fallow plot for the following season. The next summer, we assess the situation. If the weeds are bad in July, we disk in the clovers and sow sorghum-sudan hybrid mixed with soy, as a winter-killed cover crop. If all looks well in July, but the weeds are gaining the upper hand in August, we have the option of tilling it in, and sowing oats mixed with soy. If the clover is growing well, and the weeds are not bad, we over-winter the patch, and disk it in February.
Broccoli undersown with clover. Photo Nina Gentle
Vegetable Crop Options
We have a few options recorded in our calendar:
If spring is cold and wet, grow transplants for the second planting of cucumbers and summer squash.
If the winter squash patch is too wet to disk, grow transplants, but don’t sow later-maturing varieties.
If the soil is to wet to hill the spring potatoes, flame weed instead.
Abundance Options
What to do if your yields are higher than planned: increase sales by giving out samples and recipes, and feature the item on your website. Find sales to new customers (restaurants), process the crop for future out-of-season sale (if you have time), or donate it to a local food bank.
Shortage Options
With a CSA you can keep a list of who gets Sun Gold tomatoes each week, until everyone has had some. This method has the advantage of keeping the time spent picking cherry tomatoes down to a reasonable level. The sharers get some as a treat a few times in the summer, but not every week.
You can mix leaves of several greens in an attractive bunch and call it braising mix, or add unusual crops to bagged salad mix, or make up stir-fry or ratatouille packages. If a crop is really poor, it is often best to till it in and plant something else. For me, this eases the soul and lets me move on. We keep a running list of crops looking for a home, so we can replace failures with fast-growing crops such as radishes, arugula, mizuna, Tokyo bekana, or salad mix. One year when our fall cabbage didn’t fill the area intended, we used senposai, a tasty, fast-growing leaf green. If rutabagas don’t come up, sow turnips – there are very fast-growing turnips, and a small turnip is a delicacy, but a small rutabaga is a sad thing.
Hakurei turnips harvested late January. Photo Pam Dawling
It helps to have a clear and simple rotation. Our raised bed plan is ad-hoc. We make use of the flexibility: one August we were a bit late getting some tilling done, and we sowed the last cucumbers in the bed which was to have been squash. Cucumbers take a bit longer than squash to reach maturity, and I wanted to get them in the ground as soon as possible. The squash had to wait two more days. Two days can make a lot of difference when planting for fall.
Finding Resilient Crop Varieties
We always read the information about disease resistance when choosing varieties, because mid-Atlantic humidity is so conducive to fungal diseases. Depending on your climate you might pay more attention to the cold-tolerance, or the number of days to maturity. Every year we trial small quantities of one or two new varieties of important crops alongside our workhorses.
I’m always on the lookout for ways to pack more crops in, get higher yields, reduce or at least spread the workload. All while nurturing healthy soil and organic food that people enjoy.
Tweaking the Salt Wash-Down Dates
Using a lawn sprinkler to wash down the salt build up in our hoophouse. Photo Pam Dawling
I wrote about Preparing your Hoophouse for Fall and Winter on September 28. I belatedly realized that in my hurry to publish the post I let some out-of-date info slip in. We don’t do our fall salt wash-down in November any more – we prefer early October, while it is still warm enough for the plants to be improved by extra water, rather than drowned and miserable. We have switched from two days in the spring to three, as we think two days wasn’t quite enough water to get all the salt back deep in the soil profile. We had ambitions of doing three days in the fall as well, but I can tell you now, from experience, that we can fit in two days but no more.
I’ve described how we broadfork and rake all the beds in the fall, and the amount I can do in one day (along with all the other tasks) is 1/3 of a 96ft x 4ft (29m x1.2m) bed. That human limitation, and the logistics of crop rotation and planting dates, leaves a small window between preparing the first three beds to get planted (9/6-10/6), and the remaining four (10/10-10/24). It really doesn’t work well to broadfork and rake saturated soil! It’s better to have a few days for the water to soak in. So, we are satisfied with two days of salt wash-down in fall, for the time being.
Catch Crops
Mid-October photo of September-sown tatsoi and August-sown Tokyo bekana. Fast-growing crops make good use of small windows of time. Photo Pam Dawling
Last fall I noticed that some areas of some of our beds were idle between being prepped and planting dates in November and December. I hate to waste prime real estate like hoophouse bed space, So this year when we planned our bed layout, we herded all the little late sowings into one bed with the intention of finding some fast-growing crops to put in that space first. We also managed a more rational layout in each bed, planting the various crops in chronological order from the east end to the west.
Next, I researched what we might grow ahead of the main crop. There are some unknowns here. We have numbers of days to maturity for crops in ideal conditions (nice warm spring temperatures), but we are heading into colder temperatures and shorter days. So it might not work out as we hope. However, given our fondness for salad mixes, anything we have to pull up immature will still be eaten and enjoyed!
Salad Mix freshly harvested. Photo Pam Dawling
The bed in question was all ready to plant on September 30. The areas I could see for catch crops included 11/9 “filler” spinach and filler lettuce, 11/15 tatsoi #2, 12/7 lettuce mix #2, 12/18 mustard salad mix, and 12/20 radish #5.
I decided to put the 16ft (5m) of areas for November 9-15 sowings (39-45 days to go) into 45day Tokyo bekana and the 18ft (5.5m) of areas for sowings after December 7 (79 days available at that point) into 60day Cylindra beets. The Tokyo bekana came up very quickly, and I expect it will be destined for salad greens, which will be very useful as our outdoor lettuce is waning and we’ve just had a patchy frost (early for here) – the colder weather will slow crops down.
Young Cylindra beets. Photo Wren VIle
The beets have still not come up 9 days later, and the soil is 60F (15.5C). I’ll check again tomorrow. 10 days should be long enough with soil at that temperature. My niggling worry is that the salt wash-down has drowned the seeds. See Root Crops in August. If they are not up at 10 days, I think I will hoe the area and resow with something quicker – perhaps tatsoi(45 days). I was disregarding tatsoi because it will bolt in January. Umm, but this is a catch crop, that we’ll need to pull up in early December – January isn’t even on its calendar!
Carrots out! Cress in!
Belle Isle Upland Cress from Southern Exposure Seed Exchange
Last winter we grew a small patch of carrots because one of the crew really wanted to try them in the hoophouse. I wasn’t a fan because carrots are so slow-growing and provide only one harvest (usually). But I am a fan of democracy and participation, so we grew carrots. We could have harvested them sooner than we did and planted something else (in my opinion), but there they sat all winter.
Oh yes, about that “usually”: you can eat carrot tops and I have used finely chopped carrot leaves as a garnish. A major brand of crackers has carrot tops as one the herbs in their Herb Crackers. Read the small print!
This fall, as we planned our crops, I said I’d prefer not to grow carrots again, but I was out-voted, and hence we sowed carrots. Now those crew members have left, and I gave the evil eye to the carrots. I’d just read an interesting article about nutrient-dense vegetables, and learned that The 5 Most Nutrient-Dense Vegetables Based on Science are watercress, Chinese (Napa) cabbage, Swiss chard, beet greens, and spinach. We’re growing all the others, but no watercress. For the next-best thing, I wanted to try land cress/Upland Cress in our winter hoophouse. So I hoed off the little carrots and sowed Creasy Greens Upland Cress and Belle Isle Upland Cress from Southern Exposure. They take 50 days to maturity (in spring) and I note:
“The yellow blossoms help nourish ladybugs, syrphids, and other beneficial insects”
So I plan to let some flower in spring for the beneficial insects.
Creasy Greens Upland Cress from Southern Exposure Seed Exchange
Flowers for beneficial insects
September-sown shungiku (chrysanthemum greens) in January. Photo Pam Dawling
Last year, one of our trials was a collection of annual flowers to attract more pollinators into the hoophouse. None of the ones we tried seemed to do much, except for one shingiku (chrysanthemum greens) which is still flowering! Readers suggested I’d do better to just let some winter brassicas flower instead of growing special flowers. So upland cress might become part of our solution for that! We’re also growing a perennial, yarrow, to attract beneficials.
Shungiku chrysanthemum greens. Photo Small House Farm
The other hoophouse tweaks on my list are more for spring and summer, so I’ll leave those for another post.
Golden Frills and Scarlet Frills, two Juncea mustards that resist nematodes. Photo Pam Dawling
A few weeks ago I wrote about clearing tomato plants, and mentioned our hoophouse troubles with nematodes. Nematodes are tiny soil-dwelling worms that have a wide host range and are hard to control. They move only 3’–4′ (1–1.2 m) per year on their own, but people move them on shoes, tools, etc. We have had peanut root-knot nematodes (Meloidogyne arenaria) since 2011 when we found them in spinach transplants we were growing for outdoors in early spring.
White Russian kale in our hoophouse. Photo Pam Dawling
In my August 2014 post Good news – great hoeing weather! Bad news – more nematodes in the hoophouse I wrote about solarization to fight nematodes in our hoophouse (scroll down to the end of the post). The post includes a photo of our first attempt at solarizing – a bit of a How Not To! Be sure to use UV-inhibited polyethylene. This year we somehow got some construction plastic mixed in. It doesn’t work! It goes cloudy (thus not heating up the soil) and it shatters into little pieces.
There is info on dealing with nematodes from Garry Ross in Hawaii, where nematodes are a fact of daily life, in my post Cold weather, snow, thinking about nematodes from February 2015.
My most thorough blogpost about nematodes was in 2018 for Mother Earth News: Managing Nematodes in the Hoophouse.
Solarizing with clear plastic. Photo Pam Dawling
My postSolarization and crop choices to fight nematodes in August 2019 includes a photo of a much better way to solarize an individual bed. In that post I gave a list of nematode-resistant food crops, and also talked about cover crops. There is a photo of nematodes on cucumber roots there too).
Food crop choices to fight nematodes
Most resistant and most helpful are the Juncea group of mustards. I did some research into more Juncea options in Solarization and crop choices to fight nematodes. We don’t like very pungent greens, so we have not yet taken the route of planting a whole bed of Juncea types. Instead we have mapped and flagged the nematode-infested areas of our beds, and try to be mindful of what we plant in those spots. Three of our seven beds have no nematodes so far.
Open-pollinated Yukina Savoy. Photo Ethan Hirsh
This year we looked at the nematode map we had made and decided to focus our attention on the bed with the highest number of nematode patches, and grow the most resistant winter crops (of the ones we like to grow) there. That’s the frilly mustards (Ruby Streaks, Scarlet Frills, Golden Frills, all Juncea mustards, and Mizuna, a Japonica mustard), Yukina Savoy (variously reported to be Brassica juncea, Brassica rapa pekinensis, and Brassica rapa), and Russian kales (Brassica rapa).
Mapping nematode areas
See the post with info from Gerry Ross I mentioned above. We have previously tried for a “Two years good, One year bad” strategy. This was to grow nematode-resistant crops in the infected areas for two years, then try risking one year of susceptible crops. That was a bit demanding on careful management, and we haven’t kept that up.
French marigolds and sesame to deter Root Knot nematodes in our hoophouse. Photo Pam Dawling
A reader asked about cover crop choices to fight nematodes. In June 2019 I wrote about using marigolds, sesame, Iron and Clay cowpeas as warm-weather nematode resistant cover crops. We’ve also used winter wheat (in winter!), and white lupins (not worthwhile, in my experience). See that post for a few other ideas on nematode-fighting cover crops, and why we decided against some options. At that time, we decided not to grow sunnhemp (Crotolaria) because it is poisonous, although newer varieties of Crotolaria have lower toxin levels. More recently we have been growing sunnhemp, after I saw it growing so well in North Carolina. It is a warm-weather legume, so it is feeding the soil while tackling the nematodes. It does grow tall in the hoophouse, and we have taken to chopping it down with hedge shears to an ergonomic elbow-height every few weeks whenever it gets too tall. The cut tops create a nice “forest-floor” mulch effect. You can almost feel the extra organic matter nurturing the soil! (High OM levels deter nematodes.) 60-90 days to maturity.
We previously used soybeans as a short-term leguminous summer cover crop, but they do not offer the nematode resistance. Iron and Clay, Mississippi Silver and Carolina Crowder cowpeas are all nematode-resistant and can be grown in summer instead of soybeans. Sesame is a legume that is particularly good against peanut root-knot nematodes.
Iron and Clay southern peas flowering in September. Photo Pam Dawling
A Florida reader gave me information about partridge peas, which I have not yet tried: After terminating cool-season brassicas and celery between April and June, their late spring sowing of partridge peas were too late this year to be productive, because the hard seed was very slow to germinate. Partridge pea could be a good cover crop for mid- to late-summer, if you scarify those hard seeds to speed germination.
Some cover crops can be alternate hosts for pathogens like cercospora, rust, or bacterial leaf spot, so be on the lookout for new problems while solving old problems. In the deep south, beans, yard-long (asparagus) beans, and cowpeas can succumb to heat, nematodes, rust, bacterial spots, and other pathogens and pests. Senna (tall) and Partridge pea can provide “chop-and-drop” organic matter as sunnhemp does. Sunn Hemp can host foliar pathogens (some possibly seed-borne), in Florida, and does not reliably form nitrogen-fixing nodules on the roots, even when inoculated. Even so, it is useful as a fast warm season green manure cover.
The flower Gaillardia (blanket flower) is a quick-to-compost, chop and drop option for late winter to late spring, It decomposes quickly, and can provide a quick green manure. Gaillardia is nematode-resistant, great for beneficials and pollinators, but is susceptible to some foliar pathogens later in the season. You can sow Gaillardia in August, or even later in fall for early spring flowering.
Due to climate change, and the more year-round activity of nematodes, pathogens, and pests in Florida, they’ve been including more nematode-resistant grasses into their rotations. We all need to be thinking more about warmer-climate options, as climate change continues to push pathogens and pests farther north, earlier each year.
If you have a hoophouse, you may now be planning or planting crops for fall, winter and spring. If you don’t have a hoophouse, this is a good time of year to consider getting one. See Twenty Benefits of Having a Hoophouse at the end of that post. There are grants available from NRCS, including reparation levels of funding from traditionally underserved groups of people. There are now companies that will construct your hoophouse for you, if you don’t want to do it yourself, or can’t. If you do want to build your own, there are detailed instructions in my book The Year-Round Hoophouse. You can buy the book here on my Books page direct from me, or from my publisher New Society, or you can buy it wherever books are sold.
The Year-Round Hoophouse cover
I have many posts about winter hoophouse vegetables, so rather than try to write something completely new on the topic, I am going to give you a guide to find your way around the information already here.
Hoophouse bed broadforked to loosen up slumped soil. I’m happy to say our soil structure has improved in the 18 years since this photo was taken! Photo Pam Dawling
Choosing Hoophouse Winter Crops
(see also my post categories on the right side of the computer screen, for special posts on Asian Greens, Cooking greens, lettuce and root crops)
See my recent post for info about fall broccoli and cabbage. Here I provide some more information and discuss other brassicas you could grow in the fall.
Temperature and Timing for Fall Brassicas
Germination: Brassica seeds will germinate at soil temperatures from 41°F (5°C) to 95°F (35°C). 41°F (5°C) can take 45 days for some brassicas, but in summer and fall, this isn’t the end of the thermometer we worry about! In summer and fall, soil temperatures are enough to germinate brassicas in 3-10 days. Optimum soil temperatures for germination are
77°F (25°C) for most Asian greens, broccoli, Brussels sprouts, cauliflower, collards, kohlrabi, pak choy;
86°F (30°C) for cabbage, including Napa cabbage, kale, turnips and rutabagas;
68°F (20°C) for mustard greens, and perhaps arugula (which might do better even cooler)
Vates kale seedlings for bare-root transplanting outdoors. Photo Pam Dawling
Cold-Hardiness: Consult this list of winter kill (air) temperatures for brassicas, for the crops you are growing.
32°F (0°C): some cauliflower curds, some pak choy
27°F (-3°C): many cabbage varieties
22°F (-6°C): some varieties of arugula
20°F (-7°C): broccoli heads (maybe OK to 15°F (-9.5°C)), some Brussels sprouts, some cabbages (the insides may still be good even if the outer leaves are damaged), some cauliflower varieties, some collards (Georgia Cabbage Collards, variegated collards), some mustards/Asian greens (Tendergreen), radishes (Cherry Belle), most turnips (Noir d’Hiver is the most cold-tolerant variety).
15°F (-9.5°C): some broccoli and cauliflower leaves, some cabbage (Kaitlin, Tribute), Red Russian and White Russian kales, kohlrabi, rutabagas (American Purple Top Yellow, Laurentian), most covered turnips, winter cress.
12°F (-11°C): some broccoli perhaps, some Brussels sprouts, some cabbage (January King, Savoy types), most collards, Koji greens, covered rutabagas
10°F (-12°C): Purple Sprouting broccoli for spring harvest, a few cabbages (Deadon), some collards (Morris Heading can survive at least one night), Belle Isle upland cress, probably Komatsuna, Chinese Thick-Stem Mustard may survive down to 6°F (-14°C), covered winter radish (Daikon, China Rose, Shunkyo Semi-Long survive), Senposai leaves (the core of the plant may survive 8°F/-13°C), Tatsoi, Yukina Savoy.
5°F (-15°C): some kale (Winterbor, Westland Winter), many of the Even’ Star Ice Bred greens varieties and the Ice-Bred White Egg turnip are hardy down to 6°F (-14°C)
0°F (-18°C): some collards (Blue Max, Winner, McCormack’s Green Glaze), Even’ Star Ice-Bred Smooth Leaf kale
-5°F (-19°C): Leaves of overwintering varieties of cauliflower, Vates kale survives although some leaves may be too damaged to use. Lacinato Rainbow Mix kale may survive this temperature.
Frosty daikon leaves. Photo Bridget Aleshire
Your Climate: Consult WeatherSpark. com to see when it begins to get too cold in your area. At our farm, the average daily low temperature on November 30 is 36°F (2°C). Decide your ideal harvest date for each crop. Although kohlrabi can take 15°F (-9.5°C), I’d want to get it all harvested by November 30.
Days to Maturity: Next factor in the number of days a crop takes to reach maturity. Work back from your desired harvest date, subtracting the number of days from sowing to maturity (or from sowing to transplant, plus from transplant to maturity). Work back another two weeks for the slowing rate of growth in fall. And perhaps work back another two weeks in case in gets colder earlier than usual. This provides your sowing date.
Mid-Winter Harvests: For crops that survive your winter, are you sowing to harvest in the fall, during the winter, or only in early spring? Brassicas for early spring harvest only can be sown in September or October in our climate. For those to be harvested during the winter, you need to have big enough plants going into the winter, to provide sustainable harvests (once a week in November and February and more in spring, plus maybe once a month in December and January)
Overwintered Vates kale. Photo credit Twin Oaks Community
Various Fall Brassica Crops
In the summer we try to have a No Visible Brassicas Month to break the lifecycle of the harlequin bugs. Once our spring kale is finished, the spring cabbage gathered in, and the spring broccoli mowed down, the only brassicas are seedlings hidden under insect netting. Our hope is to starve out the harlequin bugs or at least deter them from making too many more.
We sow other fall outdoor brassicas a bit later than cabbage and broccoli. These get transplanted from our netting-covered nursery seedbeds, to our raised bed area which is more accessible for winter harvesting and more suited to small quantities.
Asian Greens
Outdoors we grow Senposai, Napa Chinese cabbage and Yukina Savoy. We have also sometimes grown tatsoi and komatsuna. Note that senposai grows quite large – give it similar spacing to collards.
We sow Asian greens for outdoors in the last week of June and first week of July, aiming to eat them before we start harvesting the ones in the hoophouse, which feed us all winter. We use Asian greens outdoors as quick-growing greens to fill the gap before our main fall greens (spinach, kale, collards, cabbage, broccoli) are ready to harvest. We don’t grow a lot outdoors.
If you don’t have a hoophouse, you can sow for outdoors later into the fall than we do, to get a longer harvest season than you otherwise would. And you certainly can direct seed them.
Yukina Savoy outdoors in December, after several nights at 16-17°F (-8 to -9°C) Photo Kathryn Simmons
Collards
We sow collards in the first two weeks of July and transplant the bare-root transplants from the nursery bed when they are 3-4 weeks old. We plant at 18” (46 cm) in the row, with rows 12” (30 cm) apart. (if you grow a large kale, you might want similar spacing. Our Vates kale is small)
Morris Heading collards. Photo Kathryn Simmons
Brussels sprouts
are rather a challenge in our climate, and not worthwhile. We have worked on finding the best variety (Oliver) and timing for our situation. Harvest timing is critical, as Brussels sprouts will not overwinter here.
Cauliflowers
are a tricky crop for us too. Be sure to check the “days to harvest” for each variety (they vary widely) and sow at a realistic date to get a crop before too many frosts endanger the curds. The number of days quoted for fall varieties of cauliflower already allows for the expected rate of growth at that time of year, so the 14 days for slower growth isn’t a factor. However, cauliflower is more tender, so allow for the possibility of a fall frost earlier than average.
Harvested kohlrabi, Early White Vienna and Early Purple Vienna. Photo McCune Porter
Kohlrabi
We sow Vienna kohlrabi mid-July and transplant early August at 8” (20 cm) apart in the row, with 9-10” (23-25 cm) between rows. Later sowings (up till early September) would also work for the fast maturing varieties. Superschmelz Kohlrabi (60 days from transplanting) can also be summer sown for fall harvest. It produces 8-10” (20-25 cm) bulbs, which remain tender and an attractive globe shape.
Kale
We direct-sow two neighboring beds of kale on each of 8/4, 8/10, 8/16 and then carefully thin them, leaving one plant every 12” (30 cm). These plants grow quicker than transplants, as they have no transplant shock. Meanwhile, if we have gaps, we use the carefully dug thinnings from those beds to fill them. We want a lot of kale, and there isn’t time to transplant it all. Dividing up the sowings lets us focus on watering just one pair of beds at a time. Vates kale is the hardiest variety we have found, although I’d love to find a taller Scotch curled variety that could survive our winters (Winterbor does not survive as well as Vates).
An outdoor bed of young Vates kale Photo Kathryn Simmons
Rooty Brassicas
Radishes, rutabagas and turnips are also brassicas, but I won’t say more here. look in the further resources.
Brassica Aftercare
Brassicas started in hot conditions do not usually bolt if they have enough water.
Brassica seedlings under ProtekNet in August. Photo Pam Dawling
Protect seedlings and the new transplants with insect netting if you have brassica leaf pests (most of do!) You can remove the netting when the transplants are well established, or leave it on.
Use shadecloth to keep greens cool in hot weather, or plant them in the shade of other plants.
To keep crops in good condition later into the winter, use rowcover. I recommend thick Typar 1.25oz rowcover, which provides 6F degrees of cold protection. I wouldn’t spend the money on anything thinner, it’s too frustrating! We do not normally use rowcover in the winter for kale and collards, as they will survive without. In harsh winters we lose the collards.
Cultivation is a simple matter of hoeing, weeding, watering as needed, and watching for pests.
We grow some winter brassicas in our hoophouse: Russian kales, turnips, and Asian greens – more about those in my winter hoophouse posts (includes slideshow).
