Zucchini problem

[katylaide]

I'm a new gardener and I have a nice zucchini plant growing in a large container with drainage holes. My other zucchini plant died, I'm not entirely sure what from. The problem I'm having is that the blossoms begin to grow, begin to turn the normal yellow, then either open only slightly or not at all before dropping off. My first lot of fruit from this plant died after a heatwave and I doubt any were pollinated, because the male and female flowers didn't mature at the same time. Since I'm new to gardening this plant suffered quite a bit from me over-watering it. It seems to have recovered but I was thinking that maybe I'm still watering it too much, causing a calcium deficiency. Could this be causing the flowers to drop off prematurely? And is there a way to tell when a zucchini plant needs more water? It's the middle of summer so the leaves often droop in the middle of the day then go back to normal in the evening.

[Toil]

could you describe your soil a bit more? compost? chemicals? etc...

Maybe this is a consolation prize - all squash flowers are edible! You can lightly batter, fill with something creamy (I had some with ice cream inside) and fry it. There are recipes all over. Just google "squash blossoms" or "fiori di zucca".

[rainbowgardener]

Well let's see... To start with as you noted zucchini have male and female flowers. The male ones always open up, release pollen and then drop off. The female ones open up and then if they are not pollenated will drop off too. If they are pollinated, they hang around and start making a zucchini. It often happens at the beginning of the season that the plant produces all male flowers for awhile. If pollination is the issue (watch and see if you have bees around them), you can hand pollinate.

But if the flowers are dropping off without ever opening up, that's a different thing, called "blossom drop." That is a stress reaction in flowers, where they jettison the flowers to focus on survival. I don't know about zucchini, but I know in tomatoes one of the stressors that can cause blossom drop is excess heat (above about 90 d. F.)

[seagullplayer]

You said in a large container?

If it is not outside you may very well have to hand pollinate...

[katylaide]

The plant is in a container outside. The growing medium is a layer of rotted horse and cow manure, newspaper, then compost. It is sheet mulched with leaves, rabbit manure and leftover rabbit food, mostly dead grass. I haven't used any chemical fertilisers but sometimes water them with dirty aquarium water, which is slightly higher in salt than mains or rainwater. The temperatures have been quite high, though, so I think this may be the main problem. Thanks for the advice, I'll look up blossom drop and see what I can find.

[SP8]

It doesn't take much for aquarium water to fall into the acidic or alkaline categories.

[katylaide]

Would that cause blossom drop? I use the water because my family runs an aquarium shop and the water often tends to be slightly alkaline but basically neutral. Unfortunatley I don't know the pH of the soil I'm growing in, do you think it would be worthwhile for me to test it?

[GardenMann]

I was reading about your poor zuchinni plant dropping blossoms and I thought I was reading about my own zuchinni plant experience.

Mine started off looking great and finally my first blossom. The next day it was on the ground but another one was growing, so I didn't pay much attention.

This happened day after day.

Finally I found the answer online. I had slugs.

They would only come out at night so I never saw the little critters doing the dirty deed.

I put a few lids of beer out around the zuchinni and also added some damp newspaper. They like the cool damp place to sleep during the day. And that took care of my zuchinni problem.

[katylaide]

Oh that's a thought. The slugs loved my late zucchini plant, but I never noticed them on this one. Did the slugs leave any obvious signs? I haven't noticed any tracks or eaten bits, mostly the blossoms start to rot while still on the plant then fall off soon after. For the meantime I've moved the plant into a more shady place because the temperatures here get very hot during the day and drop quite low at night, so I suspect it's the temperature that's doing it. My dad's zucchini plants are doing much better and they're not in full sun and are in a slightly cooler town. I also opened up the flowers myself and hand-pollinated the largest fruit, which are about 10cm/3in or so long, so we'll see how that goes. The damp newspaper thing is a good idea too. Slugs are welcome in my compost, but not my vegies!

[katylaide]

Oh wow, shows how much I pay attention. I chanced upon pictures of the first blossom from that plant and this one did open up nicely, and this was before the very hot weather. I have a lot of hope for the zucchini developing on the plabnt now that it's got some shade. Thanks for the advice, everyone!

[jal_ut]

You need to look at this page: [url=https://www.soilandhealth.org/01aglibrary/010137veg.roots/010137ch32.html]Squash[/url]

Then ask yourself, "How can a plant with such an extensive root system be expected to grow and do well in a container?"

It is severely stressed.

If you have any space at all that is real earth and real soil, and in the sun, try planting some zucchini there.

[katylaide]

So should I try to move this particular plant into soil or do that when I plant zucchinis next time? I think it probably is best to plant them in the ground but this one was put in a pot when I thought we'd have to move house, with the plan to transplant it when we moved, then I found out we weren't moving and the zucchini plant in my raised bed was dying so I moved the one in the pot into a larger container, which is about 70cm deep or so. And while it might be stressed in the container (unfortunately I don't have much room to spare in the ground this year), I really think the cause of the blossom drop is the heat, and maybe over-watering, because my dad's plant in an identical container is doing fine and better than his in the ground.

[jal_ut]

I wouldn't transplant it. It may decide to give you some squash yet.

Good luck.

[katylaide]

Thanks Jal_ut. I can proudly say that I am eating the first zucchini off that plant as I write! It was nicer than supermarket zucchinis, plus, I grew it myself. I think what helped this one grow to be a reasonable size was my hand-pollinating of its flower. The weather's getting ridiculous again, I'd guess about 100F, I can't be bothered converting it right now, but in the high 30s Celcius anyway, so the plant's struggling, but being in mottled shade is helping. I've just aquired some new land for gardening (my dad's empty old veggie patch), so I'll be sure to grow next year's zucchinis in the ground to give their roots room to move .