Bugs around here, and the age of the plants relative to their season. We have tremendous pathogen pressure though. Are the leaves nice or are they mottled yellow? Do you have bug poo, or frass, in the tighter leaf areas?

Poor/incomplete pollination can also cause part of it.

Dave

True, and it can be self caused. Spraying for insects harms the very insects that pollenate. It is everything you can do to ensure leafsucker death without poisoning the pollenators.

I never use chemicals. The leaves were fine until some just collapsed, while looking perfect. I haven't seen any bugs. I grow a cucumber beetle resistant variety (county fair). I think the moles and/or chipmunks may have dug under the roots and caused that. When something isn't pollinated completely.....how does that happen? So only a small part of the blossom gets pollinated? (I missed that day in cucumber sex ed.) :)

Yeah insufficient pollenation but I have to leave that explanation to the more knowledgeable around here. You might look at a diagram and see that where the parts connect they are multiple but how that becomes one fruit is not something I study. Also bacterial wilt will leave a green leaf limp look and then it dies of clogged arteries but more likely you can have virus that lets the plant live but mangles the fruit. Also if it is hot you can have trouble with pollen being viable. Shade cloth is not unknown around here, or at least reduced sun like planting on the shadow side of the okra.

Incomplete pollination is quite common with any variety of blooming/fruiting vegetable. Such plants routinely abort some of their fruit due to incomplete pollination. Cukes are just one of many.

And there are many variables - air temps, humidity, variety, ratio of males to females, type of insect and level of activity, age of plant, health of plant, number of blooms adjacent to each other, pollen availability, etc. - that contribute to it and a whole library of research into why and how it happens. so it can't be covered in a few sentences.

"Resistance" doesn't mean immunity to, it just means slightly more tolerant of.

Dave

Thanks everyone!

Dave......I've been using County Fair cucs for many years and I've never seen a cucumber beetle on them! I hope it continues. Seems like the only cucumber I can grow because of them.

I wonder if your soil pH or the level of organic matter in your soil has anything to do with it. My regular cucumbers are looking like that, too. There are lots of pollinators in my garden, though (whether or not they're giving the cucumbers any attention), but they have lots of flowers to choose from, too. There's not much organic matter in the soil, though, and it's partial clay (I'm guessing they, like many plants, prefer something else). I haven't been watering them much (so, that could be the reason, too). I don't think the compost and peat moss I gave them was enough for the soil.

Now the Armenian Cucumbers (Metki Dark Green Serpent melon) on the other hand are doing great (water or no). Being the same species as melons, they don't mind our soil. I'll probably grow those every year, now. They're huge and delicious.

I'm trying out African Horned Cucumbers, too. They're growing, but I haven't seen any flowers yet. They take a long season, I've read (maybe 120 days), but I wanted to grow them, since they provide needed water to desert elephants and other animals (I watched a documentary on it, and that's where I first learned about them). I want to try West India Burr Gherkins next year (as well as more Armenian Cucumbers).

Wow Shule......you're having fun with different varieties! I wonder if the cucumber beetle is attracted to all other varieties too? I just can't seem to grow any other variety than County Fair because of those little boogers. And they can destroy the entire crop so quickly.

Catherine, incomplete pollination is quite common and your cukes are a perfect example. This can occur for a number of different reasons.

Weather conditions and ignorant use of pesticides are a couple. But so is a lack of pollinators (not just bees) in the vicinity of your vegetable garden. You can attract bees, etc., by planting flowering annuals and perennials nearby. I have one of my cutting gardens next to the veggies....packed with zinnia, gomphrena, pentas, and other easy to care for flowering plants.

The pollinators are happy to visit the garden plants as part of their daily job.

Not polinated. The female flowers which the cucumbers grow from will be look like little cucs. Every other flower without a baby cuc is a male flower and can't produce. If you see a bunch of babies that never form it means bad pollination. Ideally spray with a hose and presentate the female blooms to the bees by spraying the leafs covering the female blooms over. Also helps to have a lot of plants. Usually you'll find more male blooms then females.

Thanks rhizo and Fastlnk. I knew that about female squash blossoms, but I didn't know that about cucumbers! I guess I'm a little slow, since I've been growing cucs for about 45 years! lol! Thanks for the tip about watering the female flowers.

I usually have lots of pollinators. This year a couple phoebes were situated around the garden, so maybe they ate too many of them........

Watering em down is also a great way to check for cucs to pick! Also prevents molds due to heavy ground cover.

If your fruits weren't fully pollinated, you might try growing parthenocarpic varieties, like Monika or Little Leaf. Parthenocarpic varieties will develop fruit without pollination (but they'll be seedless if they're not pollinated).

You might also look for cucumbers that resist bacterial wilt, though, since cucumber beetles are supposed to spread it. Here's a list of cucumbers that are supposed to resist or tolerate bacterial wilt:

Ashley, Chinese Long, Chipper, County Fair, Eversweet, Gemini, Improved Long Green, Saticoy Hybrid, Sunnybrook, Tokio Long, Marketmore 76, Marketmore 80, Salad Bush, and Regal. I think Little Leaf and Cross Country also tolerate it. I'm not sure which tolerate the beetles themselves, though, and which, if any, are parthenocarpic besides Little Leaf.

Hmm. I just found out that County Fair is already parthenocarpic. So, pollination shouldn't be the issue there, unless it's not the true variety, or unless it's only somewhat parthenocarpic.

I don't know if Armenian Cucumbers, African Horned Cucumbers (AKA Kiwano) and West India Burr Gherkins tolerate cucumber beetles better than cucumbers do (they're all different species than each other, but they're all still cucurbits). I just looked at reviews, and according to Todd, West India Burr Gherkins weren't bothered by cucumber beetles; they should grow quite well in humidity, too, from what I've read (I know southern Indiana is fairly humid; I'm not sure about the north).