Are you sure it wasn't a lack of pollination? That would be my first suspicion.
Mrs H

Yep, sounds like low pollination rates. I had kind of the same problem, had only a 70 - 80% rate. Try planting some bee attracting flowers or hand-pollinating with a paintbrush, or both.

You say it was summer... What were the temps? None of my squash plants seemed to set fruit well when the temps get real high. Some of the flowers never opened at all before dropping off. After a while, I quit holding out hopes of getting full grown squash and just picked the flowers for stuffing and frying.

I doubt it was a true pollinating problem from lack of bees - and I did hand-pollinate several times. I keep bees and they were evident as well.

Perhaps the heat variable entered into it. We did have an unseasonably warm early summer - as evidenced by the tomatoes suddenly giving a growth spurt before well established.

My fall planted crops this year (October planting) are simply great and this is the first year for using Remay. I am surmizing the moderating of temps has a lot to do with it.

This coming summer, will plant zukes a bit earlier and employ some of the Remay to see if that may be a factor.

Thanks for sharing.

Bejay

My bad, sorry, am used to mild winters. Yet another possibly useless suggestion: perhaps some pole beans on a trellis or other tall plants (vines, grapes, sunflowers) could help shade your zukes? Cheaper than hoops and remay.

This past summer I had several 110-115 degree days in my S Cal garden and had no problems with my zucchini production. I purchased dwarf bush variety seeds from Burpee and was very pleased with the vigor and production of the plants.

maximum -

I wondered if the variety might have had something to do with it. It seemed so strange, the plant produced a lot - the fruit got just so far then deteriorated.

Sorry - I had a bad experience some years ago with Fields (that I think is affiliated with Burpee), when I paid for seeds and never got them, when they were in a bankruptcy proceedings. They never did acknowledge my order, my letters, phone calls, etc. I only order from seed companies that I know will at least "keep in touch" now.

May try another seed this year anyway - possibly several and keep an eye on the temps a little better.

This gardening is truly a learning experience.

Just my 2 c's.

Bejay

I keep bees also, but there are times that my squash or other cucurbits don't get pollinated because the bees have found another flower they prefer.
You say the squash only got "so far". How large did they get and how long did they grow from the flower stage?
Mrs H

Bees sometimes do prefer certain flowers - but you are aware of this, especially if you keep them, as I do. I find borage to be the most significant plant in my garden for that purpose.

But these squash seemed to grow to about twice middle finger size - then the flower drop, and the squash stopped altogether with shriveling then. Several did go on to what I would call edible size, but most followed the "so-far, drop-off" routine. It produced a lot of flowers, and set - but only just so far - then shrivel.

I admit I grow better winter crops - and my successes with warm weather ones is sometimes "iffy" at best. I blame our need to irrigate a lot, and summer gardens require a lot more time and effort.

Bejay

I am having the same problem this summer. I was so proud about three weeks ago when my zucchini plants flowered and made baby veggies! Now, they are still the same size (3 to 4 inches long) with the flowers still attached. Those that have dropped their flowers shriveled up and fell off of the plant a day or two later. I cannot figure out what is going on here. I'll try planting some bee-friendly flowers nearby. Note: I water by sprinkler regularly and fertilize with an organic all-purpose mixture available at any garden center now (I've even spotted it at home depot this year). Should I water the zucchinis 'special', under their low leaves, or should a good soaking be sufficient?

Hmmm - interesting posting. I had almost forgotten about that. Needless to say, we didn't have too many zukes last year.

Just out of curiosity, did you plant a variety that is quite dark? I believe they called them "black" zucchini. That was the type that I had a problem with last year - as my post notes above.

This year, I planted another variety - more light speckled color - and they are now beginning to set fruit. I picked several that seemed not to have the blossom/fruit drop problem.

Not sure if this was the problem - our temps seem to be about the same this year. The only other thing, I planted them in another planter box - and that may also be a factor now.

I've been using the same old dirt - just trying to rejuvenate it with ferts, etc., and it may be time to dig out the old planter medium and replace with new compost and peat - I see another box that is newly refurbished that is doing great.

To date, I have 9 of these veggie raised bed planter cedar boxes - and they have really had a work-out over the years. As the "good" book saith - "leave part of the field fallow" or in this case, rejuvenate the soil.

Just my 2 c's.

Bejay

I'm having this exact problem- growing some 8-ball variety zucchini, got beyond excited about a month ago when the fruit started developing, but have since then only managed to harvest 2 very small fruit. The rest of the embryonic fruits begin to develop, get to about golf-ball sized, then stop growing, turn black and shrivel up. It's incredibly depressing.

I see lots of pollinating insects around the squash but I'll try the Q-tip trick anyway and see if that's the issue. My other big concern is that I've over-planted- this is my first year gardening, and I guess I really didn't believe that the tiny seedlings I was planting would grow to take up so much room- so I stupidly put two seedlings in each pot. The pots are pretty big, about 70cm across & 60cm deep, but still, the plants are definitely crowding up against each other. And in the limited growing medium of a pot, I imagine that's even more of a problem than in the ground.

The plants look fine apart from the fruit-drop problem- lots of fresh leaf growth, very bushy, lots of flowers present. A few chewed-up leaves from caterpillars but no other visible pest damage. Does anyone else have experience with over-crowding causing fruit drop, even if it doesn't seem to be causing other problems?

And, am I best off sacrificing one plant per pot so there's only one remaining? Or is that not likely to solve any problems?

Just noted that I posted on this - so felt a follow up was in order.

Sorry, I can't comment on your spacing. I'm raising in cedar box type raised beds, about 6 ft. long x 3-4 ft. wide. I do crowd plants a bit, but they don't seem to mind.

My reason for comment is that the speckled variety that I planted - as I mentioned, turned out to be quite fruitful, and I harvested quite a few for freezing.

They also received some mid-morning shade in the location, in which they were growing. The variety that I had a problem with, were dark in color. I think they called them black zucchini. Perhaps a seed mutant that just wasn't hardy enough to survive ???

I'll plant the speckled kind again next year.

Just my 2 c's.

Bejay

Had my first go at hand-pollination this morning (just pulled off a male flower, stripped the petals, and swirled the yellow bit around in the female flowers). I'll keep going as new blooms open & report back as to how well it works.

Bejay

You do know that cedar can be alleopathic to some plants?

Also sounds more like blossom drop. Did you use a lot of nitrogen ??

Byron- I used premium potting mix, a small quantity of slow-release fertiliser granules & compost when I planted. When they started flowering I added a teaspoon or so per pot of 'fruiting veg fertiliser' (which claims to be low nitrogen to promote flowering rather than leafing). Apart from that they've had Seasol a few times, which to my knowledge has no appreciable nitrogen content.

So I guess my answer is, I have no idea if I used a lot of nitrogen or not enough (although I doubt they're nitrogen deficient as the leaf growth is lush & green)- I'm not well versed in how to calculate these things, and obviously still learning how it can affect the plants. Would you recommend stopping all use of nitrogen-adding fertiliser from here on in? Any particular fertiliser regimes you reccommend to control blossom drop?

Update: hand-pollination appears to be at least partially successful, as I've just harvested the first full-sized zucchini off my plants & have two more that I'll pick tomorrow (they've already grown well beyond the size at which the other ones have been shrivelling & falling off).

Guess I'm gonna have to be out there giving my zucchinis a hand-along in the dating department if I want to be eating fresh zucchini all summer...

byron -

Perhaps cedar may be somewhat of a deterrant, but these boxes are not of the aromatic type cedar, and are well-weathered. Have had fairly decent success using them over the years.

I know we did a lot of musing about redwood sawdust in the compost pile, but the final argument was that it was OK, so long as it was well-weathered. My son works with redwood a lot, so that came up several times. I still don't use it in the vegetable compost, but OK as a mulch in ornamental beddings.

As plants are usually spaced in different boxes - mainly as other veggies are harvested, this affords me a chance to see if the same species react differently in other locations. If both react similarly, then I look for something relative to that particular situation. Perhaps old seeds, mutant seeds, similar insect invasion, etc.

If they react differently, then I would suspect soil or water technique - one box receiving better than the other.

As I mentioned in my post, I tried a different brand of zucchini this past year - a speckled variety - and it performed well in 2 different boxes.

I hope this makes sense.

Just my 2 c's worth.

Bejay

Slashy,

After 50 years of growing veggies, Low nitrohen is N= 5 or less nor more than once a month.

Is your plants still in Pots? My guess is that you have a pot bound situ. The fruit load of a plant is determined by the size of the root ball, the size of the main stalk and the amount of foliage. If your plants are still in a pot, less than a 20 gal garbage can, your probably pot bound

Bejay

Gave you my best guess w/o a lot more detail.

Hi Bejay,
What're the chances of a successful transplanting of zucchini bushes that are about 4 feet across in foliage each? I have some beds I could move them to now that didn't exist when I first potted them, but I haven't read much about transplanting veggies. Most people seem to leave them where they are for the season & plant them elsewhere next year if it didn't work out to the best.
Thanks for the help,
Slashy

Slashy, not sure if the size of the foliage will make a huge difference, but my zuchinnis were started in pots until my vege garden was completed they seem to have been quite content with being replanted into it, I just ensured that they had enough water for the first few days so the ground was never fully dry.

Slashy - sorry to be tardy answering - been on a "health" vacation.

About transplanting - I start lots of seeds inside in my particular area. We are now in our spring planting mode here in zone 10, and I will continue to start seeds inside - under lights as they like warm germinating temps, and also because many predator bugs haven't decided to retire yet (not cold enough).

I replant these in-door started zukes all the time, they are "hardened off" first when outside temps begin to drop.

But I have never transplanted a REALLY full grown zucchini plant - perhaps if you could get enough root ball and then have the new spot shaded/protected awhile, it might work.

However, you mention the zuke being a "bush" - so are we talking about a specie I'm not familiar with?

I'm of the opinion, however, if a plant likes where it is, why move it? Especially if it isn't absolutely necessary.

Just my 2 c's.

Bejay