Cucumber plants are usually monoecious meaning the plants have separate male and female flowers on the same plant. The same is true for their relatives, squash, cantaloupes, and watermelons. The flowers on cucumbers are usually pollinated by insects, but in their absence you can hand-pollinate the female cucumber flowers yourself. In the illustrated guide below I'll show you how to identify the female cucumber flower and pollinate cucumber plants in your own garden.
The female cucumber flowers grow on a slender stem off of the main vine. At the base of the female flower is a large ovary that is fertilized by the pollen from the male flowers and develops into the fruit.
The difference between male and female cucumber flowers (aside from their sexual reproductive parts) is that male cucumber flowers develop in clusters along the main vine. Male flowers are shorter and do not develop the small fruits below them like the female cucumber flowers do.
To collect pollen from the male cucumber flowers you can use a small paint brush. Insert the tip of the paint brush into the center of the flower and vigorously twirl it around to load pollen onto the brush.
You could also use a cotton swab to collect pollen, but I find the dark fibers of the paint brush to better suited for the job. Pollen is light colored and easy to recognize on the tip of your brush.
After you've loaded the brush with pollen from the male cucumber flower, pollinate the female cucumber blossom by twirling the tip of the same brush in the center of the female flower. The three lobes of the stigma do not necessarily need to be coated evenly to ensure pollination, but you'll get better results if you repeat the process with pollen from several male flowers. That's all there really is to female cucumber flower pollination in your garden.
No Female Cucumber Flowers.
In monoecious cucumber varieties male flowers open about 10 days before the male flowers open up. Male flowers also greatly out-number female flowers at rates of something like 10 to 1. Cucumber vines are veritable sausage fests during this time.
Cucumber Fruits Falling Off.
The poor pollination of female cucumber flowers is one of the main causes poor fruit setting, fruit abortion, and misshapen fruits. Because of this it is a good idea to transfer pollen from several male flowers onto the female cucumber blossom to ensure the bloom has been well pollinated.
How Many Cucumber Plants Do You Need?
You really only need one cucumber plant, cucumbers are self-fertile meaning the male flowers can pollinate the female flowers growing on the same vine.
Cucumber pollination is usually handled by bees but I had to resort to hand pollinating the female cucumber flowers on my plants because bees haven't discovered the garden on the back porch. Being efficient foragers, bees will focus on visiting flowers that are available in great numbers. The handful of cucumber flowers on my porch aren't enough to draw their attention so my cucumber flowers were not being pollinated. The other reason I pollinated the cucumber flowers myself is because this cucumber is an heirloom and I'm trying to ensure the seed stay true to type. With some luck I'll have 'White Wonder' cucumber seeds to add to my seed collection along with my lemon cucumbers.
How to Pollinate Strawberry Plants.
How to Pollinate Thanksgiving Cactus.