FieldofFlowers
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What causes female squash flower abortion?

It seems just the female flowers. They turn yellow and die before they even get a chance to bloom. Sometimes it is very early in the process, when they are still in the growing tip, other times it may be when they are just about to open. Usually it happens when they are about one or two inches big and haven't bloomed.

This darn problem happens every year,usually around July, and seems to last almost into September,with only a few that make it inbetween.
Please help. I want to get a better harvest than that and I rather not have to wait until the end of August,when the vines are usually dead at the roots and stems.

Once again, it seems to be the female flowers.The male flowers are pretty much unaffected. They develop and bloom as normal.

(P.S. I'm sorry for the lack of space between some letters. My spacebar is on the fritz.)

tylianna
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Try hand pollinating the female flowers. That is the only reason I can think of that would cause the fruits not to form. Unless the weather is too hot/cold?

I'm sure someone with more experience can help you :)

FieldofFlowers
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I do hand pollinate them when they do open. I've been known to sometimes go a day or two early, break open the petals and place the end of a male flower right over the correct part. I've gotten one or two squash to grow just by that.

But sadly lately, they aren't even getting big enough for me to do that... They drop off just about as soon as they've formed. Here in MN we don't tend to see 100+ heatwaves. Our temps shouldn't have been a problem, I don't think? Unless they abort at temps around 85-90 degrees?We've had about a whole week averaging about 85 with a few days peaking close to or above 90. The vines get wilted around mid day regardless of how much water they've received.
Overall, I wouldn't think temps in the 80's would be a problem. Aren't they supposed to grow where weather is hot?

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rainbowgardener
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Yes, squash should be thriving with weather in the 80's. And no it isn't a pollination issue when the blossoms are dropping off that little. It's called blossom drop and it is a stress reaction. Other than too hot or too cold, one thing that can cause it is over watering or heavy clay soil that stays too wet and holds too much water. The plant roots staying wet don't get enough oxygen so they can't absorb nutrients and the plant starves and drops blossoms.

garden5
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rainbowgardener wrote:Yes, squash should be thriving with weather in the 80's. And no it isn't a pollination issue when the blossoms are dropping off that little. It's called blossom drop and it is a stress reaction. Other than too hot or too cold, one thing that can cause it is over watering or heavy clay soil that stays too wet and holds too much water. The plant roots staying wet don't get enough oxygen so they can't absorb nutrients and the plant starves and drops blossoms.
I agree, there are a several things that can stress a plant. How have they been getting watered? If they've been dry for some time, that could cause it as well.

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applestar
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OT Re: SPACE BAR -- Try picking up the keyboard and shaking it -- vertically, and upside-down. If that doesn't help, try vacuuming the keyboard. If that doesn't work, with the power turned off, gently run a stiff feather or paint brush around and under the space bar, and vacuum again. Using a straw held (tightly! -- or you'll lose it in the vacuum hose and have a whole 'nother set of problems :wink:) halfway inside a crevice tool helps too. Sometimes, all it is is a piece of something that got caught underneath, blocking the key action.

FieldofFlowers
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I'll try to get a visual. It's happening to nearly all of my squash, no matter where they are in our yard. :( Okay one Acorn squash seems to have set fruit, but it is in a container.


Grrrr. I'm so frustrated. I would have had about 4, maybe 5 zucchini, but they are all turning yellow right there on the stalk before even blooming. This problem has also happened last year with two of our neighbors. I just don't get it. As soon as we hit about 87, 88 degrees or 90, then poof all female flowers drop off. They shouldn't be that weak.

re: spacebar: I took it off, shook out, and tried to clean the keyboard. It is a really old compact one. There is only one button on the center under the key and a wire that connects to two ends. The key only works if I hit it from the center, but not the ends.

FieldofFlowers
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Here's a visual. Not the best, but it will have to do.

[img]https://img.photobucket.com/albums/v73/Butterflyhornet/AfricanViolets/Problems/yellowed-aborting-female-fl.jpg[/img]
Not looking so good for the Burpee Greyzini squash...

Just for curiosity, I explored a community garden in another location in the city I live. I found one acorn squash had set and was about the same size as mine, if not just a little bigger. I guessed, both it and my acorn squash bloomed and set at the same time. There were a few other squash varieties that had set, all about the same size and probably same time frame.

The interesting thing is, nearly all of the little developing fruit had all turned yellow and looks like it will drop off just like mine are looking. At least I feel a little less bad about my own failure to grow squash, but I am still trying to figure out what is going on.

I tried to do more research on it on google, but not finding many results that truly explain why this is happening, much less articles I can read without it being too technical or restricted. One article I could find, seemed very complicated.


Now, I have a new question, Is there anyone else here living in the Twin Cities? How are your squash turning out? Have any squash since July set fruit or bloomed (female)?

It seems after July 1st there has been a lot of fruit abortion. This includes our black walnut tree and possibly our pepper plants as well.

garden5
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In the pic, it looks like your flower has not yet matured enough to open, perhaps give it more time.

Also, when the little "finger zucchini" are small and turn yellow and fall off, that is usually because the flower opened, was not pollinated, and then fell off.

:idea: What time of day do you check your flowers? If you are checking them in the afternoon, it may appear as they have never opened, but what actually happened is they were open in the morning, but closed back up by the time you saw them.

We'll get this thing figured out yet :wink:.

FieldofFlowers
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An update, without a picture. (I'll have to try rebooting my computer to get it to read my usb drive and camera.)

They haven't changed much, but the biggest one looks like it grew just a little and is turning slightly brown around the blossom end. It feels somewhat squishy to the touch, as if the inside is rotting.
Usually I find the inside to be brown and rotten. This happens before the bud opens.
I do plan to post pictures after they fall off, hopefully with a cross section, so you can see the rot inside.

The good thing is it looks like some new buds are growing, so maybe I have another chance of getting something. Just worried because temps are expected to rise into the upper 80's (87, 88 degrees towards the end of the week.) Will that cause further abortion?[/quote] Not to mention, yet more rain is in the forecast.
Last edited by FieldofFlowers on Tue Jul 13, 2010 12:29 pm, edited 1 time in total.

ken1940
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I'm having the same problem here in the San Francisco Bay area. Lots of male blossoms but the female ones shrivel, turn yellow and fall off before they are even close to opening. Some of the plants look healthy, but none are really vigorous this year. Other home gardeners in my area are reporting much lower than normal yields this year from all their plants. We have had below normal temperatures out here this year, especially at night.

garden5
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ken1940 wrote:I'm having the same problem here in the San Francisco Bay area. Lots of male blossoms but the female ones shrivel, turn yellow and fall off before they are even close to opening. Some of the plants look healthy, but none are really vigorous this year. Other home gardeners in my area are reporting much lower than normal yields this year from all their plants. We have had below normal temperatures out here this year, especially at night.

More than likely, it is due to the stress from the temperature. Blossom drop occurs when the plants abort fruit set in order to focus on survival.

tedln
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With yellow squash, I sometimes have all male or all female blooms. That makes it easy to determine why I am not getting any squash. Other times I have a good mix of male and female blooms, yet no fruit sets. When I notice some fruit shriveling, I start hand pollinating and it resolves the problem. When I see some natural pollinators around, I stop hand pollinating. It seems there are periods when natural pollinators just aren't around to do their jobs.

If they drop off without opening, it probably is a temperature problem so long as the plants look healthy and unstressed.
Ted

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Troppofoodgardener
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I have succesfully grown zucchinis since August. It has been a slow process but my plant has produced 2 big and healthy zucchinis (18-26cms).
Since then, I have noticed female buds form but don't grow beyond 4-5cms. There is no chance to pollinate them as the petals do not open. I check religiously EVERY morning and the previous successful zucchinis opened in the morning. I water regularly once every morning, and don't think I over- or under-water my plants.
Lately I noticed a zucchini female growing beyond the normal size, but the petals remain shut. Yesterday it opened, but instead of the usual orange innards, this zucchini flower has a pale seed-like disposition. [I tried attaching an image but it didnt work!!]
I pollinated it with pollen from an open male flower (that's how I got the previous ones to grow) even though it's probably too late/unnecessary.
Where I am, the temp averages 32 degs Celsius which is 89-90 Fahrenheit.[/img]



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