Aljonezn
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Squash all shriveling up before female flower opens

I started all my squash indoors in April. Zucchini. Yellow squash. Acorn squash and pumpkins. I’ve had issues with all of them doing the same thing. Tons of male flowers. Females and fruit shrivel up and turn yellow before the flower has even had a chance to open. I tried adding milk for calcium but it hasn’t done much. I’ve been hand pollinating when a female does happen to open and almost all of them have still died. What am I doing wrong. My pumpkin plant is huge. Like 12 feet long or more.

pepperhead212
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Welcome to the forum!
Sorry to hear about this. Sounds like the hand pollinating should be taking care of a lack of pollinators, if that was the problem, but if the flowers are not even opening, then there must be something stressing the plants. I can't grow any of the plants you list, due to squash vine borer (a.k.a. SVB). Way back, when I was still trying, before I learned what the problem was, I would get similar results, before I would start seeing the other symptoms, like wilting, and eventually, the SVBs would be obvious from the outside of the vines. I hope this isn't your problem. I would maybe get one or two zucchini, before all the rest would be just shriveled up, then the plants would wilt, even though well watered, then some of the vines would lose the green color, and appear shredded, in areas where the SVB have gotten to the surface. It's a slow death, but it starts out like you describe, since the larvae are small, at first.
Here's one article, describing them, with a photo of the moth.
https://www.almanac.com/pest/squash-vine-borer

All I can grow is butternut, or other moschata squash, because of these.

Aljonezn
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Thank you pepperhead. Sadly I have found evidence of the pest you describedin my pumpkin. Killed an adult and found a very small grub in the stem of a leaf. I’m really hoping it hasn’t gotten to my other squash. ☹️

pepperhead212
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Oh no... I was hoping that wasn't the problem, even though it sounded like it could be. If those other squash are showing some of the other symptoms, they probably have them.

There is a method for treating these things, that some gardeners do, but I only got mediocre results, at best - injecting Bt into the vines. Here's the top link that came up for that:
https://homeguides.sfgate.com/inject-sq ... 56110.html

Problem with this is there is always some new growth, esp. with winter squash, and it's hard to keep all of those things treated! Some swear by it, however.

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rainbowgardener
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If your problem is the squash vine borer, there are things you can try to prevent it. The SVB pupa looks like this

Image

The eggs are laid in ones or twos at the base of the vine stem. As soon as the larva hatches it burrows into the stem and begins eating its way around. When it is big enough it emerges, goes into the soil and pupates. Those pupae are buried an inch or so down in the soil and over winter there. When planting you can dig all around in the area and see if you can find any.

You can try applying Tanglefoot to the base of the stem. It is sticky stuff that the moth sticks to so hopefully can't lay her eggs (or maybe just can't leave after she does it?). Of course the stem keeps growing and if it roots into the ground further out, sometimes the SVB can bore in at those spots too. So you have to keep applying. You can keep wiping the stems down to get rid of any eggs. You can just keep hilling up and burying all those stem bases. You can inject BT into the stems. Once you spot signs that the stem has been invaded, you can make a little slit and extract the larvae (but there is often more than one and they are very small at the beginning).

As you can see, many of these solutions are labor intensive and really only work if you check almost every day. I have tried most of these options (but not the BT). I have managed to slow the process down, so that I get a couple more fruits before the vine dies, but I have never managed to save the plant. Mostly I have given up growing summer squash.

If you do pull a squash plant that the borers got to, be sure you kill the larvae in it, before you compost it, so that at least you prevent another generation.

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applestar
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Agree to all of the above. I have tried the BT injection and I think it just slows them down, not manage to save the plant. If you treat early enough at first sign of burrowing, maybe they would be more susceptible to treatment while they are small?

I excerpted a couple of posts from my 2016 garden thread that dealt a lot with SVB infestation —

Subject: Applestar's 2016 Garden
Jul 30, 2016
applestar wrote:This morning, one of the three Butta zucchini plant is doing this: BER on the medium sized fruit and female blossoms not developing and browning

Image
This is the 2nd plant of the three to be doing this and the first one has dramatically stopped growing and is failing to develop fruits even though it was loaded with female flower buds just a little while ago. I think these are likely to be more signs of the SVB induced decline. The other two that I took out were doing this a week ago.

I might just harvest the femal flower buds as baby zukes tomorrow and take out all three lush green-looking living dead plants. At least I could then use majority of the plant matter as compost ingredients -- I just have to inspect, extract the SVB's, bag and discard damaged parts just in case I missed any.
Subject: Applestar's 2016 Garden
August 4, 2016
applestar wrote:Well, Butta zucchini plants are still trying to produce --

Image

But the volunteer squash outside the garden fence wilted overnight, so I decided to pull it. It didn't get a chance to grow a female blossom -- not even a bud, so I never found out what it was. Oh well.

I hunkered down in the hot sun and dissected the basal stems so I could take pictures and post.

Image

After finding 5, I began to wonder what the heck I was doing -- it was nearly noon and miserably hot, :roll: ...so I called it quits, fed those to the goldfish :twisted: , and bagged all the suspect parts and composted the upper good portions -- not even one diseased leaf. What a waste. :evil:

-- you can see near center of the bottom photo where I cut the vine and found evidence of burrowing further up the vine (to the right) so I cut a little further up to where the cut was clean. There were TWO SVB's in that little segment. Also notice in the left middle photo there is a leaf with brown evidence of burrowing in the leaf stem. You need to watch out for those, too.

imafan26
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I don't have problems with squash vine borer. I have other issues, namely fruit flies. However, the same fix may work. If it is a bush squash, you can isolate the problem in a hoop house or under insect netting. It is important to make sure the netting is sealed at the ground level so nothing can get in.

I have seen people put aluminum foil around the base of the stems where they like to burrow as a physical barrier. I don't know how well it works.

Butternut squash,cucumbers, melons, and watermelons are not bothered as much.

Planting off season helps if it is possible. If a second crop is planted now (July), then the vines will mature after the SVB season is over.

If you do have SVB, do not plant related crops in the same area. The SVB is a seasonal pest and hibernates in the soil until next year. In my small yard, it would not be practical to plant squash far enough away, but I have rotated to other crops for up to 2 years for other problems. Till or turn the soil several times after removing the vines to expose any of the pupa in the soil. Sift the soil to try to sift them out. The borer will lay eggs in the first 5 inches of soil.

This is something I have to do with peppers. Pepper weevils also show up in summer and attack the peppers causing peppers to ripen prematurely and be black on the inside. The weevils are only active for a couple of months and they do not travel far, They return to the soil after they have completed their cycle. I can avoid them by not planting peppers in the areas of my garden where they are active.

You can make a trap. SVB moths are attracted to the color yellow and you can fill a yellow pail with water and set it out. There are pheromone traps, but they will only trap males.
https://extension.umn.edu/yard-and-gard ... ine-borers
https://extension.illinois.edu/hortanswe ... ogenID=113
https://extension.umn.edu/yard-and-gard ... ine-borers
https://savvygardening.com/how-to-preve ... ganically/

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rainbowgardener
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People do say that you can grow your zucchini under netting. If you do it from the beginning and the netting is tight to the ground, maybe you can keep the SVB's out. However, lots of squash plants are large and spreading, so not easy. If you do this, you have to hand pollinate, since you are also keeping pollinators out. AND as noted above the pupae are in the soil. Unless you have sifted thoroughly, you may just be closing the SVB moth in with your plant.

I have tried the aluminum foil. Like other physical barrier methods, it must be constantly maintained as the stem grows out and older stem roots in (the borers can sometimes bore in at those points also). It is difficult to keep the aluminum foil wrapped tightly enough to keep the pests from sliding under. Easiest is burying all the stems under a pile of compost.. It works about as well as the aluminum foil, which is to say it slows the process down, but does not ultimately save your plant.

GRR!! :twisted: :twisted: This is the worst pest in my garden. Nothing else kills big healthy plants as fast and as consistently.

pepperhead212
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I once tried growing zucchini under ultra light Agribon, and sealed around the edges by piling a layer of soil around it. They still got SVBs! I also waited 10 years, before trying - also not successful. Two of the many things that I tried - none successful.

Aljonezn
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Thanks everyone.

greenstubbs
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I have heard that if you wait and plant squash around the 4th of July you'll have better success from SVB and other squash bugs. They say that by then, the bugs have past mating season and that's the key. I haven't tried it yet to see.

pepperhead212
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That was one of the myths that I squashed about this. I planted some seeds in late August, just to see, and the plants still got SVB!

Aljonezn
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So quick update. I pulled the pumpkin out because leaves were yellowing and female flowers weren’t even making it to flower. I found two very very small svb grubs in it but nothing that was big enough to kill my very large pumpkin vine. So I’m thinking something else had to be going on. This is my first year with a garden and I think that I need to get healthier soil going. Maybe it was lacking something. But still my other squash plants are not really doing so well either. So far only three zucchini and two yellow squash out of ten plants. I have some worm castings tea marinating right now but I’m not sure how much that will help things. Maybe in a few years things will grow better for me. Seems my garden is awfully slow. :?:

Aljonezn
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Poor pumpkin.
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Aljonezn
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Pic of the yellowing leaves before I pulled it out.
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