What are your nighttime temperatures running? The article below says that the problem you're experiencing has been linked to night temps above 65 degrees F. in pumpkins and winter squash. If you suspect that could be the cause, you might try keeping the soil damp (not sloppy wet) and apply an organic mulch that will keep the soil temps a bit lower. (The info is way down the page under Stigma Death.)

Good luck. This is a new one to me.

Sandy

Here is a link that might be useful: Pumpkin and Winter Squash

My butternut squash don't have this problem, they are setting fruit just fine. It's just the patty pan squash and the zucchinis that have the problem.

But yes, the night time temps. are well above 65F, daytime temps above 90F and humidity is around 90%. Its summer here, but I've been having this problem for longer than that.

I sort of doubted this, also, because we don't have the problem in high summer either. But it was the only reference I could find to this particular problem.

Nann0n, you may have to do some detective work to figure this one out. Here are a few questions you might think about.

Are there any differences in how you treat the patty pans and zukes from the rest of the garden? Any fertilizer or chemicals that could have been applied in their spot that weren't used elsewhere or were used at different rates? Different manure or compost applied? Is their area wetter/dryer than the surrounding garden? What about sunlight, is it adequate? Any herbicides used anywhere near the garden that could have drifted?

If you grew these plants from seed, you might contact the seed company for ideas. I've always found them to be very helpful. If you bought plants, check the variety name and find a seed company that sells that particular squash and call them anyway. If plants, check with the company where you bought them and see if anybody else has reported similar problems.

Do you have an agricultural agency in your country? If so, give them a shout and see if they have any ideas.

I've been raising vegetables for many years and teaching veggie gardening for some time but this is new to me. I'd love to hear the answer to this one. Good luck!

Sandy

My dear mother-in-law absolutely hated squash and her husband loved it so she would go out when he was at work and pull the male blossoms off. He never knew why he couldn't get any squash and kept planting more and more every year and getting more and more frustrated. He always blamed it on bad seed. I hope you don't have that same kind of problem! LOL

Here's a post that GW Squash expert WeirdTrev made that addressed a similar issue. Hope it helps with yours.

Posted by weirdtrev Z7 MD (My Page) on Tue, Jun 2, 09 at 15:17

Do you have any fruits already on those plants? Every female flower is not able to become a squash, you will lose many. With most vining squash (including your tromboncino) once a female is pollinated subsequent females will wither away. This is because at that time the plant is not able to support multiple fruits. If you remove the pollinated fruit or the vines get bigger you will have more females. Also, If you don't pick your Romanesco zucchini often the same thing can happen. Maybe you forgot to pick one and had a really large zucchini, well that will definitely cause other females to abort before ever opening. You might promptly remove that large zucchini but the damage is done and it can be weeks before you get another.

Personally, I have experienced that problem with the blossom not opening on a zucchini and I resolved the issue by growing in a different location. Not sure if the location had sun/water/nutrient problems, but moving it fixed the problem for the future. And if your other squash are located away from the problem squash, then location is definitely the issue and you should figure out what is different between it and the successful locations in your garden.

Hope that helps a little!
Susan

All the squash are being grown together at the moment, but the last lot I put in were in a different place altogether so it might just be my yard/location.
Unfortunately the females aren't aborting because of a fertilized squash, because that would mean that at least I'd be getting one squash. They are just dying, but the plant is healthy.

I might just try another spot in the garden and see how I go again. Third time lucky? I hope so.

That's a funny story Barbe, poor fellow though.

I read a recipe for zucchini blossoms and I picked some female flowers from my zucchini plant without reading more...oops. Basically, I picked the female flowers from the ends of 2 inch baby zucchini hopefuls already starting to plump into their future form. Did I ruin their hopes of turning into adult zucchinis by removing the female flowers from the ends of them?

My zuchini lost all of it's female flowers when I went away for four days and there was no rain.
Basically my problem was lack of water. They are all doing well now with lots of female flowers.
(night time temps here are well above 65)
I don't know if that is your problem though-but, I would guess some form of stress.

Could it be a bug? Squash bugs or vine borers infest and sometimes aren't noticeable. Do you look for groupings of reddish brown eggs on your plants.

I know you probably do, but no one else mentioned it. Also, why don't you hand pollinate when you see a male and female, even by forcing the flower open to catch it before it falls off. A long thin paintbrush dipped down into it will not disturb the flower, first in the male and then the female. It might work and once you get it started past this stage, it might start allowing it to pollinate itself.

You might try catching ants or a bug known to pollinate to drop down into the male, catch them on their way out, and put them into the female. Even if it's not open, you can cut a slit to help it along. This might not work at all, but it's a thought.

If I remember correctly they open in the morning and only stay for a day. That's why the bees show up early in the morning. If you're going to try to manually pollinate them, you need to do it very early in the morning right after they open.

In case you didn't notice, the flowers get progressively more yellow until they open. That's a good way to know how many will probably be open the next morning.