Edamame/Soybean shade crop?

[flowerweaver]

This is the first year I've grown edamame/soybeans and I have 12 types in the ground, rows spaced at 15", about 300 square feet. They are 53 days old and look fine in the morning and evening when it's still cool, but are beginning to show a little distress midday as the temperatures climb into the 90's. I know they don't like hot weather (and it's only going to get hotter), so this is entirely an experiment on my part.

I am thinking about either putting up 50% shade cloth (which I have plenty of) or perhaps interplanting something taller that can provide partial shade. Candidates at this time would be sunflowers, sorghum, or amaranth. What do you think? Would you use any of them (or something else?) and at what spacing?

[zeedman]

Wish I could be more help... I grow a lot of soybeans, but in a climate very different from yours. My first reaction is that if the plants only wilt in mid day, but perk up again toward evening, there should be no cause for concern. Even mine do that on hot days. The issue is probably water stress, from low humidity in the air as well as soil moisture. In my experience, soybeans really thrive on high soil moisture - to the point where they had record growth here, after flooding rains that drowned almost everything else (yardlong beans share that trait). I'm assuming that you irrigate? If you mulch heavily, that might help... mulch would preserve soil moisture, and if the mulch is moist, could raise the local humidity around the plants. The mulch would also help to lower the soil temperature in mid day, and there's something to be said about keeping cool feet in a hot climate.

I didn't grow soybeans when I lived in San Diego, so I have no direct experience in that regard... but it was a little too hot to grow tomatoes unprotected. Shade on the West side - to protect from the afternoon sun - was highly effective. A trellis of pole limas worked well for that purpose. If you are looking for something to interplant now, though, I'm not sure what to recommend. It would have to be something that can itself take the heat, and grow rapidly enough to quickly provide shade - without overwhelming the soybeans. Of the candidates you mention, a light interplanting of sorghum would probably be the best choice. Amaranth grows quickly, but at the spacing you are using, it would probably smother any soybeans nearby.

Most edamame soybeans get about 24" tall here, with rows spaced that far apart. I've tried spacing them more closely in the past (rows 18" apart), which only crowded them & drove them to reach even higher. If soybeans grow the same way for you, then at your spacing, they will probably form a dense mat as the plants approach maturity - which could be a good thing, in terms of preserving soil moisture. The "if" in that statement is the impact that your latitude might have on the soybeans, since most edamame soybeans sold commercially are bred for Northern latitudes. As a soybean collector, I will be very interested in hearing your observations.

[flowerweaver]

I think you've hit the nail on the head zeedman I'll start by mulching with some oak leaves until I can find straw. Unfortunately straw is very expensive and difficult to come by, and the hay is coastal Bermuda which is one of the worst weeds a garden can have. It's now growing where we feed our animals so I know those rhizomes can spring back to life. We've also tried alfalfa as mulch and it tends to smother the crops.

Would be surprised if my soybeans even reach 12", as everything grows shorter than expected in the desert. Right now they are about 7 inches tall and top watered by a sprinkler for 4 hours each night but will probably get switched to a drip line before the heat of summer. We aren't able to use commercial drip line because the holes are so small it clogs within a few weeks. We have a sediment filter on our well, so it must be from mineral deposits. We used to soak everything in buckets of vinegar weekly; it was like doing laundry and a PITA. Instead we now use half-inch black tubing that we laboriously drill larger holes into. So, it's not exactly a drip line but it delivers precise water where it's needed.

I don't know if it's the poor soil, alkaline water, intense sun and heat, or a combination of all of them. Last year we experimented with shade cloth in our main garden and things seemed to thrive (plus it was pleasant for us humans to work the beds).

When did you plant your soybeans? I have the feeling I should have sowed them before March but planting them was a late decision and I didn't know how cold hardy they were. This is the first year my fava beans have reached maturity and they were fall planted. The ones I've planted in the spring for several years always succumbed to something. So, I'm wondering if soybeans could also be fall planted and just covered when the freezes were severe or extended?

That's so great you are a collector of soybeans! Maybe you know more about these varieties, which came with little information. In my little experiment I am growing all non-GMO:
Agate
An Dunscaja
Belekaya
Hakucho
Jewel
Krasnoarmejscaja
Sapporo Midori
Shirofumi
Wielnaska Brunatna
Organic Soybean from my store that I use to make soymilk

Interestingly, the Shirofumi are the largest and prettiest plants and seem less affected. They are very uniform, and as I recall, so were the seeds. You can see them in the middle of the third row in from the right side.

[zeedman]

An interesting list... I wonder if you got those from me somehow, or from someone I trade with. Possibly someone in Colorado, to whom I've sent most of my collection? I grow all of those except for Shirofumi. I can give you more info on all of them in another post, but it's too late for me to do it justice tonight.

[steev]

I think soybeans really don't like my farm: too hot, too dry; too un-custodianed.

[flowerweaver]

zeedman I bought them from Victory Seeds and Sage Thymes Seeds, the latter of which is in Lakewood, CO--is this your connection? Would love to hear more about them when you have time.

steev I've got two out of your three!

Gave the soybeans extra water midday, and we've dug up some mulchy stuff from down along the creek to put around their feet. The feed store says it will be at least a month before wheat straw shows up.

[philagardener]

Wow - Sage Thymes has a neat listing - how can you not love a soybean named "Aan tu bai hua lu da dou"?

[flowerweaver]

OK, I planted my soybeans in early March and someone in North Carolina said theirs were in the ground a month before mine, so I assumed I got them in a bit late. I was just reading a Texas Agri-life article on planting soybeans in central Texas and it said May through early June was the optimal time to plant because of the timing with our rains. (What rain, says I?)

So, I'm wondering if I should try some now to compare how they fare with the ones I started earlier? I'll have a few free beds now that spent kale is coming out.

[flowerweaver]

Almost all of my soybeans have pods! I think the mulching and extra midday watering helped--thanks again for the suggestions. The flowers were minuscule, I kept waiting for them to get bigger. Don't laugh, but my plants are probably only six to eight inches tall.

[steev]

I planted some black soy from a store last year which did well, but I left them a week too long, so they all shattered; I didn't feel like picking them from the soil one at a time. I'm watching for them to sprout and will be more diligent, if they do.

Went by the store to see if they had seed, but they only had canned soybeans, not my preferred sort for sowing.

[flowerweaver]

How will I know it's time to pick them? Mostly they are for dry beans so I was planning to leave them on the plants as long as possible. I wouldn't want to pick them from the soil either.