Cucumbers don't happen

Question: For about the last 3-4 years of growing cucumbers I have scarcely gotten 1 or 2 cukes each summer. In years past I was giving them away like mad. Presumably a pollination problem, but I don't know why given that I use no pesticides and have been encouraging native pollinator plants. I have been growing the same kind (Straight Eight) each years, with good quality seeds. My cucumber plants look healthy (see picture), and they flower, but no fruit. Should I try hand pollination, and if so, how do I do that? And do you know what else I might do to promote pollination? Or might it be another issue?

responder: Answered by the Home and Garden Information Center (HGIC), University of Maryland Extension. For timely gardening information and tips, subscribe to our Maryland Grows blog and quarterly newsletter. Follow us on Facebook, Instagram, and YouTube. Replied July 23, 2024, 3:33 PM EDT
response: It sounds like you're covering all the bases, especially by growing some pollinator-attracting plants in the yard, though weather might be playing a role. High summer heat and other environmental factors can promote the formation of male flowers over female flowers in cucumbers and other vegetables. High heat can also kill pollen, so even if male and female flowers are present simultaneously, the male flowers might be rendered infertile. Granted, we don't have excessively high heat all summer continuously, but if any sources of reflected heat (a nearby wall, plastic mulch, a stone pathway, etc.) happen to be near the plants, that might be contributing to heat buildup or overnight temperature levels remaining higher than the plants prefer.  If you do see male and female flowers open at the same time, you can definitely try hand pollination. Guidance can be found in the page (and its included links): Pollination of Vegetable Crops in a Changing Climate. In a future year, perhaps experimenting with a parthenocarpic variety will ensure more reliable fruiting since those types don't require pollination to set fruit.  Miri

responder: The Question Asker Replied July 23, 2024, 4:55 PM EDT
response: Thank you. This is fascinating information.   I had heard that tomatoes might not set fruit with high night temps, but didn't know all that about cucumber blossoms. Is that also true of squash? Actually, the last several years I have had bumper crops of tomatoes but not cukes, but sadly this year my tomatoes are very small and few. Probably heat (again), I guess. And/or drought. And I had never heard of parthenocarpic cucumbers. I have room to plant some of those and some of my (formerly) tried and true and see what happens.  Miri, you have often responded to my Ask an Expert queries, and always send me great advice. Thanks. I am thinking of trying to earn the Expert Gardener certification (is that the right word?) next year, so I won't need to pester you all with a bazillion questions.    Be well, Deborah   On Tue, Jul 23, 2024 at 3:33 PM Ask Extension <<personal data hidden>> wrote:

responder: Answered by the Home and Garden Information Center (HGIC), University of Maryland Extension. For timely gardening information and tips, subscribe to our Maryland Grows blog and quarterly newsletter. Follow us on Facebook, Instagram, and YouTube. Replied July 23, 2024, 5:17 PM EDT
response: Thank you Deborah, and it's no bother -- this is what we're here for.  You might be thinking of the Master Gardener program; it has a volunteer requirement component, but there is a relatively new alternative (but with much more limited capacity at present) to learn similar information with no volunteer time required, which is the Sustainable Horticulture Certificate. It was only developed recently, and might be refined as we receive feedback and make updates to the content as needed. There would be a lot of overlap in the content presented between those two options.  Generally, what affects cucumbers can affect summer and winter squash, as they are all cucurbit family crops, so yes, high temperatures might kill pollen or trigger flower sex ratio changes in both plants.  Miri