Modern Homesteading Interview, Things I’ve Changed My Mind On

Hoophouse squash, tomatoes, and cucumbers.
Photo Alexis Yamashito

In April I did a pleasant phone interview with Harold Thornbro of the Modern Homesteading Podcast  about how year round gardening in a hoophouse can increase yields and the quality of vegetables and extend the growing season.

You can listen to it here:

https://www.stitcher.com/podcast/modern-homesteading-podcast/e/60326060?autoplay=true

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The rest of this post is about the agricultural things I’ve changed my mind on in recent years.

Sowing Leeks
Leek seedlings growing in an outdoor nursery bed.
Photo Kathryn Simmons

The first one that comes to mind is where and how to sow leeks. In Sustainable Market Farming I describe sowing leeks in outdoor nursery seedbeds. We grow leeks for eating from October to March, so even though leeks grow very slowly and need 12 weeks to transplant size, we don’t need to sow them super early in the year. Also because they are so cold-hardy, they don’t need greenhouse conditions. To save greenhouse space, and the bother of watering so many flats, we took to sowing them outdoors. To make this work, you do need weed-free beds. Leeks compete poorly with weeds. Sometimes things went wrong. One year someone decided to “seed-bomb” the fresh bed with poppy seeds. Weeding those tiny leek seedlings was torture! Another time, an overenthusiastic worker ran our new exciting wheel hoe too far onto the bed and eradicated part of a row.

Leek seedlings in flats in April.
Photo Pam Dawling

One year the leek seedling bed wasn’t ready in time to sow, and we sowed rows of seeds in a coldframe, after removing the winter spinach (or maybe we were still growing lettuce in the coldframes then.) This worked well. The next year we tried sowing the seeds in 4” (10cm) deep flats, and putting the flats into the coldframes right away (rather than germinating them in the greenhouse). Still no wasted greenhouse space! On very cold nights, we cover the coldframes, so it was a bit warmer than if we’d just sowed directly into an outdoor bed. The plants grew a bit quicker and we realized we didn’t need to start so early. They were easier to take to the field in the flats, compared to digging up the starts and carrying them in little buckets with water. We had reduced losses of seedlings, so we reduced the amount of seed sown in future years. It’s an easier system, with a more satisfying success rate.

Sunnhemp as a Cover Crop
Sunnhemp cover crop at Nourishing Acres Farm, NC.
Photo Pam Dawling

 Sunnhemp (Crotalaria juncea) is a warm weather leguminous cover crop that I’ve been admiring at various farms in the Southeast in recent years. I’ve been thinking it would be valuable ion our hoophouse and in our gardens. It fights root knot nematodes! I mentioned it recently at a crew meeting, only to be reminded that I previously spoke against growing it as the seed is poisonous! I’d completely forgotten my earlier opinion!

This summer cover crop can grow to 6’ (2m) in 60 days. It thrives in heat, tolerates drought, fixes nitrogen, suppresses nematodes, makes deep roots that pull nutrients from deep in the soil, and it dies with frost. It sounds fantastic, I really want to try it!  It looks a bit like small sunflowers, and according to Southern Exposure Seed Exchange  it  won’t make mature seed above 28 degrees N latitude , so won’t become a self-sowing invasive  in Virginia. Sow in rows 2’-3’ (0.6-1m) apart. If it gets too big, mow when plants reach 5’-8’ (1.5-2.5m) to prevent the stalks from becoming tough and hard to deal with. ¼ lb sows 250 sq ft. (¼ lb = 114 g, 250 sq ft = 23.2m2)

Sowing Sweet Corn
Young sweet corn with a sprinkler for overhead watering.
Photo Bridget Aleshire

I mentioned earlier here, that I’ve changed my mind about the necessity to put up ropes over corn seed rows to keep the crows off. I suppose there are fewer crows these days, sigh. Not needing the ropes makes the benefits of sowing with the seeder greater than the benefits of sowing by hand, so long as we can irrigate sufficiently to get the seed germinated. When we sowed by hand we watered the furrows generously, which meant we did not need to water again until after the seedlings emerged. If we hit a serious drought, the old method could still be best. Overhead watering does germinate lots of weeds, including in the wide spaces between the corn rows, so we need to factor in the extra hoeing or tilling when we weigh up the pros and cons. So, I’m a “situational convert” on this question!

How to Kill Striped Cucumber Beetles
Striped cucumber beetle in squash flower.
Photo Pam Dawling

I wrote about these beasties here. We handpick the beetles in the hoophouse squash flowers, hoping to deal with the early generation and reduce future numbers. One year we had our first outdoor squash bed very close to the hoophouse and the beetles moved there. In desperation I used Spinosad, an organically approved pesticide. It is a rather general pesticide, and harms bees, so I carefully sprayed late in the day and covered the row with netting to keep bees off. It worked brilliantly, taking a fraction of the time that daily handpicking takes. I became a convert to that method, but no one else on the crew did, so we went back to hand-picking.

Pruning Tomatoes
Hoophouse tomatoes in early May
Photo Bridget Aleshire

I used to maintain that life is too short to prune tomatoes, which grow at a rapid rate in our climate, and get fungal diseases, necessitating sowing succession crops. The past couple of years I have removed lower leaves touching the soil, and this year I reduced the sideshoots on our hoophouse tomatoes, which are grown as an early crop here.(We’re about to pull them up in early August, as the outdoor ones are now providing enough). I do think we got fewer fungal diseases, and the diseases started later compared to other years, so I am now convinced that removing the lower leaves is very worthwhile. We also got bigger fruit this year, which logically fits with reducing the foliage some amount.

Is There Such a Thing as Too Much Compost?
Too much compost?? A commercial compost windrow turner.
Photo by Pam Dawling

I used to think the more compost the better. Now I am more aware that compost adds to the phosphorus level in the soil. I wrote about that here. I am not as alarmist as some people about high P in our situation, but I do now think it is worth paying attention and not letting the levels build too fast. I have got more enthusiastic about growing cover crops at every opportunity, and finding legumes to include in cover crop mixtures at every time of year (see above about sunnhemp). I was already a cover crop enthusiast, but as my experience increased, I got my mind round more possibilities.

Using Plastics
Rolling biodegradable plastic mulch by hand
Photo Wren Vile

In my youth I was anti-plastic, If I were growing food just to feed myself, I’d probably still find ways to avoid almost all plastics, but growing on a commercial/professional scale (and getting older) has led me to appreciate plastics. I still don’t want to do plastic mulch, except the biodegradable kind, but I’ve come to accept durable light weight plastics for their benefits. Drip tape saves do much water, reduces weed growth. Plastic pots and flats are so much easier to lift! I do still pay attention and try to make plastics last a long time, and frequently salvage plastic containers others discard. I’m awed by the possibilities of silage tarps or old advertising banners, to keep down weeds without tilling and pre-germinate weed seeds so that when the covers are removed, few weeds grow. This was called by the awkward name of “occultation”, but is now more often referred to in English as tarping.

Hornworms

Lastly, I have a post on Mother Earth News Organic Gardening about hornworms, but you read it here first!

Challenges with hoophouse squash

 

Gentry yellow squash.
Photo Pam Dawling

We grow one bed (90 ft or so) of yellow squash in our hoophouse, to extend the season earlier. This year it is a dismal failure. We have had splendid success some years, with good harvests for several weeks before our outdoor squash are ready. What has changed?

One aspect is climate change including more variable temperatures in spring. This makes it harder to get frost-tender crops started in our greenhouse, and causes us to delay transplanting into our hoophouse, to avoid a wipe-out. We do have good thick rowcover to put over the hoophouse crops, but rowcover can only do so much. Also, it’s not simply a matter of life or death. Extended cold can permanently stunt tender plants.

Striped cucumber beetle in squash flower.
Photo Pam Dawling

Striped Cucumber Beetles

Our second biggest problem is striped cucumber beetles. We reckon if we can deal with the cucumber beetles in the hoophouse, we’ll be dealing with the mothers of that year’s population, and things won’t get so bad outdoors. Or, rather, if we don’t deal with them in the hoophouse, they’ll get really bad outdoors (we’ve seen that happen on nearby watermelons and squash).

Our approach is to nip the beetles in the squash flowers first thing each morning, with tweezers. It’s important to tackle them early in the morning, because as the day warms, so do they, and they take off flying around, making them hard to catch. We ignore the more numerous, smaller, cucumber flowers, because the beetles prefer squash flowers, and we’re only prepared to spend a limited amount of time on this task.

The hunting season for cucumber beetles here is on average about a month long. In 2017 it was early and only 8 days 4/25 to 5/3. This year we didn’t start till 5/4 and we’re still finding some 6/5.

One year we tried trapping the beetles using pheromone lures from Johnny’s. We hung the pheromone with a yellow sticky card from the wire hoops that previously held up the rowcover. I thought they were successful, but others on the crew didn’t want to use that method again.

One year we sprayed with Spinosad, which is organic and was very effective, but we try to avoid any spraying if we can. Recently we revisited the decision, and re-committed to hand picking.

Yarn-wrapped tweezers intended to kill cucumber beetles and pollinate squash at the same time (with prey).
Photo Pam Dawling

To attempt to deal with our third problem while addressing the second, I just tried wrapping yarn round the tweezer arms, thinking they might do some pollinating for no extra effort, while I hunted beetles. It wasn’t very successful. The tweezers we’re using are very pointed and the yarn slides off. Too much yarn prevents the tweezers closing aggressively enough.

Unpollinated squash
Photo Pam Dawling

Unpollinated squash

Our third problem is unpollinated squash. The baby squash are hollow, and sometimes rot at the ends. We spend too much time removing the unpollinated ones to encourage the plants to try harder producing new squash, and to prevent the spread of molds which sometimes grow on the hopeless squash.

We look for bush varieties, as we don’t want sprawling vines in the hoophouse. In order to get harvests as early as possible we choose varieties that are fast-maturing. Since 2008 we have usually grown Gentry, a hybrid yellow crookneck squash with a bush habit, that mature in just 43 days from sowing in normal temperatures.

Early in the season some varieties of squash produce a lot of female flowers, which can’t get pollinated until some male flowers appear. Low temperatures and high light intensity promote this female sex expression, ie female flowers rather than male flowers. But our problems went on beyond the arrival of male flowers.

In 2006 we grew Zephyr, a beautiful bi-color hybrid yellow squash with green ends, which is our favorite for outdoor crops. It takes 54 days to maturity. In 2007 we grew Zephyr and a few Supersett, a 50-day hybrid crookneck yellow squash. We didn’t choose Supersett again, so I suppose we didn’t prefer it. What did we grow in the first few years 2004-2005? We didn’t keep good records.

In 2015 we tried Slick Pik YS 26, a 49 day hybrid, attracted by the claim to spinelessness. It didn’t do well for us, and we came to call it Slim Pickins. Some of the plants were weird. About 4 out of about 45 plants had darker green leaves and no female flowers. The male flowers were abnormal, halfway to being leaves. The petals were thick and greenish, and the flowers were small. Then the flowers dropped off, producing no fruit, so we didn’t grow that variety again.

Rotting unpollinated squash.
Photo Pam Dawling

Another option we once tried is a parthenocarpic variety. Parthenocarpic crops can set fruit without pollination. Some squash varieties, like Sure Thing (48d), Partenon (48d), Cavili (48d), and Easypick Gold (50d), are sold on the strength of being very good at setting fruit without any pollinators. See this article for all the details.

It’s not an all-or-nothing attribute – a number of squash varieties have some level of parthenocarpic capability.

In one study of zucchini (see the article link above), fruit set without pollination varied from zero to 42%, depending on the variety. In the 1992 study, 33 varieties of yellow summer squash were compared. Follow-up studies in the next few years. Chefini (51d  Breeder: Petoseed Co (SQ 28) Seems not to be commercially available any more), Gold Strike (a yellow straight-neck squash, likewise seems unavailable), Black Beauty (50d) and Black Magic (50d)  all did well. In a study including yellow squash and zucchini, most of the high-parthenocarpic producers were zucchini rather than yellow squash. Of yellow squash, Gold Strike seems unavailable, but Gold Rush (52d), Golden Glory (50d) look promising

See also Steve Reiners’ paper Producing summer squash without pollination – Ranking varieties

In that study Golden Glory (50d) is the big winner. Runners up are mostly zucchini: Dunja (47d), Noche (48d), Partenon (48d), Costata Romanesco (52d semi- bush variety), Safari (50d), Multipik (50d yellow squash). After that there are several that scored 29% down to 6% in the trial, and then a bunch of zeroes. Our much-beloved Zephyr scores zero in that trial!  I read that the retail demand for yellow squash is less than for zucchini, so most of the research goes into zucchini.

Next year, I’ll propose we try Golden Glory and Noche (a zucchini that does well for us in hot weather). Or perhaps Dunja, which scores higher.

A bee pollinating squash.
Photo Pam Dawling

Encourage pollinators

This is something else we could pay more attention to next year. We have now got honeybees again, after several years without. We could also plant a succession of flowers that attract pollinators, timed to flower the same time as the squashes. If we plant them in big pots we can cycle them in and out of the hoophouse for their “work shifts” and retire them when they stop flowering. See this blog post from Southern Exposure Seed Exchange: 10 tips for Attracting Bees and other Pollinators and Harvesting Great Cucumbers, Squash and Melons. Carolina Farm Stewardship Association also has some useful info about native squash bees. I’ll need to study up before next spring!

Import pollinators

We could buy boxes of bumblebees from Koppert. But that gets pricey. I prefer attracting existing pollinators.

Squash bugs making more squash bugs.
Photo Pam Dawling

Minor Problems; Squash bugs

We also have squash bugs, but they aren’t such a big problem for us.

Squash bug eggs.
Photo Pam Dawling