Stop shriveling cucumbers

or, “A brief photo tutorial on hand-pollinating cucumbers.”

A bit of introduction:

Last year, I was having problems with getting cucumbers to grow. I’d see the flowers, I’d see the baby cucumbers (which I later learned were female flowers, more about that below), and then the baby cucumbers would shrivel. I posted about it in the “Shriveling cucumbers” post, which has consistently been the top-viewed post on this blog. Between the suggestions of a friend of mine and people commenting on that post, I learned that my cucumbers weren’t being pollinated properly. This is probably because my garden is about 4 stories above ground where bees are unlikely to fly (why fly 4 stories up when there are all kinds of nice flowers right near the ground? ) People with traditional in-ground gardens or container gardens at ground level are much less likely to have problems with their cucumbers remaining unpollinated. I had some success with hand-pollination last year (and got all organized with red and blue strips of t-shirt fabric!), but I never actually described my technique. For the sake of completeness, I decided to write this post.

First, you need to know the difference between a male flower and a female flower on the cucumber vines.

Male flowers look just like little yellow flowers with pollen-holders in their centers:

side-view of a male cucumber flower

“center” view of a male cucumber flower

Female flowers are also yellow, but are easily distinguished from male flowers by the mini-cucumber that is right behind the base of the petals. The center of a female flower is also different from the male flowers. Instead of containing pollen-holders, the female flower has a pollen-receptor.

side view of a female cucumber flower. note the miniature “pre-cucumber” just behind the base of the petals.

“center” view of a female cucumber flower

I use a small, soft paintbrush to pollinate my cucumbers. I gently grasp a male flower at its (his?) base and swirl the paintbrush around to collect pollen.

collecting pollen from male flower on soft paintbrush

If you’ve done it right, you’ll see a dusting of yellow pollen on the bristles of the paintbrush. To deliver the pollen to the female flower, gently grasp at its (her?) base and brush the pollen into the center of the female flower.

delivering pollen to female cucumber flower

It’s also worth re-posting some of the links that were given to me in comments of the “Shriveling cucumbers” post, because they were really helpful:

http://ask.metafilter.com/65155/Cucumber-woes

http://extension.oregonstate.edu/news/story.php?S_No=991&storyType=garden

I found another method for hand-pollination on this blog:

http://gardeningwithwilson.com/2008/02/23/pollinating-cucumber-flowers/