Hoophouse Squash Variety Trial, Garlic Recap, Flowers for Organic IPM

Golden Glory Squash in our hoophouse in mid-June.
Photo Pam Dawling

Hoophouse Squash Variety Trial

A month ago I wrote about our hoophouse squash variety trials for pollination issues and blossom end rot. I think our problem was mostly unpollinated squash, rather than blossom end rot. Go to last month’s post for valuable links to distinguish the two conditions.

We planted 15 Golden Glory zucchini (good at setting fruit without pollinators) along with 25 Gentry yellow squash (a favorite variety, except that we had pollination troubles with it in our hoophouse for several years). The trial is almost over, we’re about to pull those plants, and we have plenty of squash coming in from our outdoor plantings now. The first outdoor planting includes some Golden Glory too, so if I have more news I write about it when it happens.

Gentry yellow squash in our hoophouse in mid-June
photo Pam Dawling

As I said last time, I recorded the number of small rotting squash we removed. The Golden Glory produced far fewer rotten unpollinated fruit.

Date 15 Golden Glory plants: rotted fruit Golden Glory: rotted fruit per plant 25 Gentry plants:

rotted fruit

Gentry:

rotted fruit per plant

5/13 2 0.13 12 0.48
5/14 2 0.13 5 0.2
5/17 0 0 32 1.28
5/21 15 1 54 2.16
5/27 9 0.6 39 1.56
6/4 13 0.9 29 1.2
6/10 2 0.13 11 0.46
6/14 2 0.13 9 0.43
Average per plant   0.38   0.97

 But low numbers of rotted fruits is not the only goal! Yield is important too, and the healthiness of the plants (which relates to yield).

We noticed that the plants were starting to die, and we thought of bacterial wilt. But when I tried the test for that disease, the results were negative. The test is to cut through the plant stem, rub the cut ends together, then slowly separate them. If the plant has bacterial wilt, there will be bacterial slime in strings between the stem ends when you slowly draw them apart. We got nothing like that. More research needed!

We pulled the dying squash, put them in a black trash bag and set that in the sun to cook.

Diseased squash, mid-June.
Photo Pam Dawling

Here’s what we found:

Date 15 Golden Glory plants: Number of healthy plants Golden Glory: Percentage of plants healthy 25 Gentry plants:

Number of healthy plants

Gentry:

Percentage of plants healthy

6/4 15 100% 25 100%
6/10 15 100% 24 96%
6/14 15 100% 21 84%
6/18 10 67% 20 80%
6/24 6 40% 18 72%

Initially, the Gentry started to keel over, then suddenly the Golden Glorys weren’t so glorious!

As far as yield, we did not measure it much. We only have notes from one day, 6/10. We harvested 7 squash from 15 Golden Glory plants (47%) and 14 Gentry from 24 plants (60%). Different people harvested on different days, meaning sometimes they were picked bigger than on other days. My sense is that the Golden Glory were not as productive throughout their harvest period. They are beautiful, the plants are open, easier to harvest from, and we had fewer rotten squash, and initially fewer dying plants. Is this enough to recommend them for an early hoophouse crop in future years?

My inclination is to also try another variety that is rated well for setting fruit without pollinators (hence fewer tiny rotting squash) and try harder to also record yield as well as problems next year!

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Garlic Recap

Our garlic is at the “Trim and Sort” stage, but depending where you garden, yours may be at a completely different stage. See my blogposts from the previous year, when I posted my Alliums for the Month Series.

Trimming garlic stems.
Photo by Brittany Lewis

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For people in colder climates than Virginia, you may be just starting to harvest your garlic. Learn from Margaret Roach (who grows in Massachusetts) in A Way to Garden

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Here are a couple of allium resources that didn’t make it into the Alliums for the Month Series

Mulching alliums

The Nordells on mulching alliums

RAMPS

Barry Glick sells ramps

“The Cat Is Out Of The Bag”!!!
Sunshine Farm & Gardens
696 Glicks Road
Renick WV 24966 USA

Ramps plants.
Photo Sunshine Farm and Gardens

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Flowers for Organic IPM

This is my post on the Mother Earth News Organic Gardening Blog

Organic Integrated Pest Management involves tackling pest problems one step at a time with ecologically-based practices, starting with reducing the chances of the pest ever getting a grip on your crops. Follow prevention with avoidance, and finish with pest-killing if needed. I recommend the ATTRA online publication Organic Integrated Pest Management. Each  page is a poster, complete with good photos and concise clear info.

In May we transplant flowers in our vegetable garden to attract pollinators and pest predators. We like a combination of sunflowers, dill, borage, cosmos, calendula, tithonia (Mexican sunflowers), zinnias. See my earlier Mother Earth News post Insectaries: Grow Flowers to Attract Beneficial Insects

We sow sunflowers about every 10ft (3 m) in each of our bean beds. We are growing sesame surrounded by French marigolds in our hoophouse to deter nematodes, which we have in parts of our hoophouse soil. Sesame is apparently particularly good in deterring root knot nematodes, the type we have.

French marigolds and sesame to deter Root Knot nematodes in our hoophouse.
Photo Pam Dawling

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