How to handle poor cucumber pollination
Question: Last year we had trouble with our cucumber plants. They didn’t really form many cucumbers. We had a lot of flowers and the vines were quite large and seemed healthy, but we only had two or three cucumbers from each plant.
We’ve never had this problem before. Was it the variety or is something else going on?
Answer: I’m hearing from more and more gardeners who are facing the same issue you are. Poor production from cucumber plants can be due to several different factors, but the most common is a lack of pollination.
Cucumbers and other members of the squash family of plants produce separate male and female flowers on each plant. The male flowers, which have straight flower stalks, provide the pollen for the female flowers but do not turn into a cucumber. The female flowers, which have a swollen stem that looks like a mini cucumber, require lots of pollen from the male flowers in order to grow a fully developed cucumber.
The first flowers to open on a cucumber vine are always males, and there are always more male flowers on any given plant than females. This is the plant’s way of hedging their bets and making sure there is an ample amount of pollen around when the female flowers begin to appear.
Don’t panic if you only see male flowers for the first several weeks. Females will appear.
Trouble comes when there aren’t enough insect pollinators around to move the pollen from the male blooms to the female.
Cucumber plants are pollinated by several different species of bees, including honey bees and several of our smaller native bees. Surprisingly, they’re also pollinated by cucumber beetles, which we normally consider a pest in the cucumber patch.
Do not spray synthetic insecticides in the vegetable garden, as they may have negative impacts on pollinators. Find alternative ways to control pests (traps, row cover and organic pesticides that are labeled as safe to use on food crops and around pollinators, for starters).
You should also be sure to include plenty of flowering herbs and annuals right in your vegetable garden to keep pollinator populations high. Some of my favorites are borage, sunflowers, oregano, dill, cilantro, salvias and zinnias.
Do it yourself
If you still aren’t seeing any fruits develop, it’s time to take matters into your own hands and pollinate the plants yourself.
Early in the morning, head out to the garden and pick a newly opened male flower. Tear off the petals so you’re left with only the flower stalk and the anther (the part of the male flower that produces the pollen). Take the anther of that male stalk and rub it against the center nub of a female flower (this is the style where the pollen is received).
Many grains of sticky pollen must find their way onto the style in order to form a cucumber, so spend about 5 to 10 seconds on each female flower. The same male flower can be used to hand-pollinate 3 or 4 female flowers.
You can hand pollinate other members of the squash family, too, including winter squash, zucchini and more.
If you do this every few days, you’ll have plenty of cucumbers form on your plant.
Horticulturist Jessica Walliser co-hosts “The Organic Gardeners” at 7 a.m. Sundays on KDKA Radio with Doug Oster. She is the author of several gardening books, including “Attracting Beneficial Bugs to Your Garden,” “Good Bug, Bad Bug,” and her newest title, “Container Gardening Complete.” Her website is jessicawalliser.com. Send your gardening or landscaping questions to [email protected] or The Good Earth, 622 Cabin Hill Drive, Greensburg, PA 15601.