My Wartham butternut squash are dying!

[Grandma99]

They have plenty of water. I water slowly - starting and stopping and starting again so it all gets wet and water comes out the bottom. But the temperature hit 91F today and please see picture. Oh dear.

Also, the leaves are rimmed in gold and their veins are turning gold. They've been doing that for a week or so now. I find no bugs. I released lady bugs and I had root watered with MultiCrop (only one teaspoon in gallon of water). They also have organic fertilizer granules fed to them two weeks ago. They have several large squash on them but they are still green - I don't want to lose them!

Should I begin watering twice a day when temps are over 90? Should I amend the soil with something else? Should I add shade cloth? My cherry tomatoes drooped today also but not nearly as bad as the squash. Is it normal for them to wilt that badly?

On the gold rims, only the leaves on the first half of the plant are turning yellow. The newest leaves are dark green (although they are wilting). All the older leaves are turning completely yellow so I remove them. The plants have almost no leaves except on the newer half of the plants. Is that normal?

ADDED: The bugs you see on that last picture are lady bugs - I released them and they stayed although it's only been 24 hours!

[applestar]

While slight drooping is normal in hot sun, Sagging leaves like that is extreme. Since Waltham is a full size vining squash, I suspect the container you are using is too small, and it has become root bound/it is not getting enough space for all the roots and the roots are becoming compressed.

All squash are stressed by root disturbance (unlike some other crops) and yellowing dried edges is a symptom when seedlings to be transplanted have become overgrown in the container — its one of the reasons it’s better to directly sow in the ground if there is sufficient days in the growing season. Squash seedlings will suffer MORE from transplant shock and can often become stunted or die even after being planted in the ground or larger container.

Usual recommendation for one typical full size vining squash plant is a 1/2 barrel or a 24 inch diameter container. There are modern hybrids and “Bush” type or personal size fruit type that are better suited to container culture.

...another possible factor is C.moschata like butternut tends to need a longer growing season to mature than some other varieties of squash. So the vines grow for longer and probably need more root space.

This is an older reference but I like it because it provides an idea of how much root space vegetables could potentially need — they don’t have C.moschata like butternut, but do have C.maxima and C.pepo

Root Development of Vegetable Crops: Chapter XXXII
Squash (C.maxima)
https://soilandhealth.org/wp-content/up ... 7ch32.html

Root Development of Vegetable Crops: Chapter XXXIII
Pumpkin (C.pepo)
https://soilandhealth.org/wp-content/up ... 7ch33.html


One way to offset insufficient main container size for vining squash is to place satellite containers and train the vines to set down roots in them — but I’m not sure if that remedy might be too late if your is already yellowing.... sorry for the negative diagnosis.

[dveg]

As noted, squash normally wilt in the heat, and SVBs might ordinarily be an issue. But there are no SVBs in the west, so I think that's not your problem. The issue is whether or not the leaves spring back in the evening. But be careful. If you overwater to counter the wilting, you'll probably end up with root rot, and then the wilt won't go away. My squash wilts routinely in the 90-100F heat of the afternoon, and they bounce back when the sun gets low. The way to deal with it, I have found, is just to look the other way. I water a half inch every three days under these conditions, and I have a few inches of mulch.

[Grandma99]

What are SVBs ... all Google shows is Silicon Valley Banks.

[SQWIB]

What are SVBs ... all Google shows is Silicon Valley Banks.

Squash Vine Borers

[dveg]

Consider yourself awesomely lucky that you don't know about squash vine borers. Most of the right side of the nation is infested with them, and we grow squash here only with difficulty. I've gardened in the west, and in Texas (as well as a few other places), and while growing squash used to be drop-dead easy in the west, it's now for me more about squash dropping dead, unless you are very very careful. I regard SVBs as being BY FAR the worst garden pest.

[Grandma99]

I'm new to gardening and I've been pushing on the bases of my squash trying to check for vine borers, haha. Good to know they're not in Oregon! My squash was due to be watered that evening when, in the heat of that day, they collapsed as shown. With this heat, I think I'll begin to water in the mornings. Why don't I water mornings now? My dog, Ginger, likes to lay on that patio when the sun first comes up and watering gets it wet (which she hates). I carefully only water the soil - never leaves. I might give my squash an added drink mid day when temperatures are so high. And next year, I'll grow them (one each) in my larger 2'x4' planters.

So the gold rimming the leaves isn't a sign of an issue, that anyone can tell? I had the beginning of aphids (very tiny black specs) and within one day the ladybugs eliminated them! I see no other indications of squash bugs, fruit flies or eggs. Also, might it help if I cut off the tips of the vines to stop it's new growth? Might that force it to focus on maturing what's there?

I can't thank you all enough for helping me. I'm willing to put in the work and study very hard but this first year is difficult. Experience is a tough teacher. First it gives you the test and THEN it gives you the lesson.

[dveg]

But the question is, do your leaves stop drooping in the evening? If not, your plants are dying, perhaps from overwatering. Seriously - don't overwater! Stick your finger in the soil. If it is moist, it doesn't need watering.

[Grandma99]

They bounced back in the evening. They look good again. All the new growth is dark green. But the leaves from the base up about 30" are dying off. They turn solid yellow so I cut them off. And the leaves above that 30" and before the new growth are rimmed in gold and the veins are turning gold, unlike the new growth.

I should mention that I had noticed the leaves droop in the heat. That happens whenever the temps get above 85 which we've had for a few weeks now. And they spring back when it cools down. But this wilt pictured above seemed VERY drastic. I thought it was a serious sign of stress on the plant. For now, I'll water as I've been doing and if they droop again like this, I'll just check them after it cools off.

[Grandma99]

When reviewing Applestars links, the roots are VERY shallow so using my finger should work fine to indicate whether they're getting enough water ... unlike tomatoes which can have their roots in the bottom of the pot. My indeterminate cherry tomatoes collapsed when there was still moisture in the top 6" of the soil but were obviously dry deeper (those pots are 24" deep).

So squash have very shallow roots - and a finger is good indicator! Thank you!

[dveg]

As noted, that's pretty serious drooping, but if they come back in the evening, I don't think you have a major problem. They should come back in the evening WITHOUT adding more water, if the soil is already moist. In my experience, similarly stressed plants do have the lower (first) leaves turn yellow, and maybe fall off. Not sure what to make of the gold rims, though that may just be a more lasting indicator of heat stress.

I should add that if these plants are in containers, especially black containers, best not to have the full sun shining on the side of the container. You could wrap a few sheets of newsprint around the container to help insulate it from the sunlight.