If you’re having trouble with pollination of your cucurbit plants, don’t give up. Give hand-pollination a try.
Cucurbits (the family of plants including squash, cantaloupe, watermelon, pumpkins, and cucumber) are notorious for having pollination problems. A short botanical lesson reveals why. Rather than having male and female parts in one flower, like a tomato plant does, cucurbits have separate male and female flowers on the same plant. That means pollen must be carried from one flower to another (male to female) in order for pollination to occur.
Here’s a little more in-depth description of how cucurbits flower. The first flowers on a cucurbit are male, and these may remain on the plant for about a day before falling off. Sometimes, this falling scares gardeners, especially those growing squash, because it seems like blooms are dropping and all is lost. But don’t fear, the female flowers come along soon, and they’re the ones that produce fruit. Female flowers show up on the plant usually a week or two after the male flowers start showing. After that, there should be both male and female flowers on the plant at any given time while the plant’s still blooming.
You can distinguish male and female flowers a few ways. The easiest way is to look at where the stem meets the flower. On a female, this area will look like small fruit. Male flowers are typically shorter, don’t show immature fruit, and often appear in clusters. Here are a few examples of male and female flowers on cucurbits.
First, some male flowers…
And now for some females…
So here’s the trick. Cucurbits need cross-pollination from male to female flowers, but this requires a little more of nature, namely of the bees that pollinate our vegetables. If bees aren’t present for some reason (such as broad-spectrum pesticides being sprayed nearby or heat or rain keeping the bees under cover), then fruit either doesn’t appear or it appears small and shriveled up because it’s not well pollinated. At this point, human intervention is necessary. As we’ve been telling the many folks on the website who are seeing flowers but no fruit, you can try pollinating your cucurbits by hand. Here is a lesson in hand-pollination using my Straight Eight cucumber plant as our subject.
The method of hand-pollination shown above should work well for all cucurbits. You also can remove male flowers and touch the anther (in the center of the male flower) to the female flower’s stigma (also in the center), or shake the male over the female, to transfer the pollen.
For those of you with copious bees, congrats! (I am thankful to be one of these people at the moment.) For the rest of you, I hope hand-pollination helps you have a great harvest of cucumbers, melons, pumpkins, and squash. Happy growing!