Thursday, August 13, 2009

How to Hand-Pollinate Your Vegetables

In our butterfly garden, I always let nature take its course. Native plants are strong and self-sufficient, and the butterflies always found the right plant on which to lay their eggs. I expected the vegetable garden to be equally independent once I gave the seeds a good start, adequate water, fertile soil, and mulch. I was partially correct, because the plants have grown big and healthy without any gardener intervention. The exceptions have been the squash and zucchini plants which cannot survive the squash vine borers on their own, and the cowpeas which need help to survive the aphids.

What I didn't realize about vegetable plants, however, is that a vigorous plant does not necessarily equate with an abundant harvest. My watermelon plants are a perfect example, with long vines spreading through the garden, lots of flowers every day, and not a single fruit. The squash plants, too, produced lots of blooms without anything edible in sight. And so I learned that nature sometimes needs some help in the vegetable garden, at least when it comes to pollination.

There are two types of plants -- those that produce male and female blossoms, and those that only produce one type of flower. The former include plants such as zucchini and squash, cucumber, and watermelon. In the latter category are eggplant and bean. These are called "perfect", "bisexual" or "complete" flowers because everything is contained within each bloom. Hand-pollinating is not difficult for either type of plant, but the approach is different.

When a plant produces both male and female flowers, the key is to find the females so that they can be pollinated. The female blooms have an immature vegetable just under the flower, so if you look closely you will see a miniature squash, melon or cucumber. This is the easiest way to be sure you have a female flower. The centers of the flowers are also different, so with larger flowers such as squash, you can quickly distinguish between male and female by looking into the flower. This is not easy with a tiny flower like those on cucumbers and melons, so stick with looking for the baby underneath.

I have yet to discover a female without many males nearby, so if you are lucky enough to find the female flower, the hard work is over. Once you've located the female, remove a nearby male flower. Carefully peel off the petals, leaving only the stamen which is covered in yellow pollen. Take this stamen and rub it all over the pistil of the female flower. When I want to be extra sure of success, I remove a second male flower and repeat the process. I try to remember where the female flowers I've pollinated are located so I can check back the next day. If the flower is still open (which it usually isn't), I pollinate again.

With plants that have "perfect" flowers, the process of hand-pollinating is even easier. No need to remove any blooms from the plant. In fact, each flower is a potential future vegetable, so you want to keep as many as possible on the plant. For these flowers, I use a make-up brush. I've read that others use a small paint brush or Q-tip, but I love my retired eye shadow applicator. Whichever implement you choose, just take the brush and gently rub the pollen from the stamen (these are the pollen-covered filaments that surround the center) onto the pistil. The pistil is the female center of the flower -- the tip is called the stigma -- and this is what you must pollinate. The flowers on these plants can stay open for several days, so it's not a bad idea to repeat the process every day or so. You will know the process has worked if the flower closes but doesn't fall off the plant. Expect a baby vegetable soon.

Hand-pollinating is one of the easiest garden projects around, and it's playing god on a very simple level. In just a few seconds, you can help your plants conceive. If you see your plant flowering without producing much, a failure to pollinate may be to blame. The solution is easy, with or without your Chanel makeup brush.


  1. I was out trying out the brush technique for pollinating as my cucumbers and asian squash don't seem to get pollinated as well. I have more female flowers than males. Two questions. How many females do you think I can pollinate after placing the brush on one male ? And do you have to clean the brush to use in between different types of plants, i.e. squash, cucumbers, etc. ?

  2. You are lucky to have so many females -- I always have the opposite problem. You should be able to pollinate two or even three females per male. I suggest you pluck the males first to make it easier to see how much pollen is left after you retrieve some with your brush for each female flower. Cucumber flowers are small, making it particularly hard to see what's going on when the flowers are still on the vine.

    With respect to cleaning your brush, it never hurts and is especially a good idea if you're pollinating several varieties of the same vegetable. I go down the line pollinating all our different eggplant varieties using the same brush, and usually just wipe the brush on my dress between varieties. Despite my lazy cleaning technique, I only created a cross-pollination problem once, an eggplant that was half Black Beauty and half Sfumata, which was actually quite pretty.

    Cross-pollination between different types of vegetables should not be a problem so cleaning your brush quickly should be adequate.

  3. Thank you for the details on hand pollination of eggplant. It's quite helpful :). I'm going to try it out.

  4. I tried hand pollinating the eggplant but there wasn't any pollin (yellow powder) on the stamen (both on the outside or inside of the stamen). It has a yellow colour but there is no powder on it. Do you know why there is no pollin? Btw, this is the first flower on the eggplant and it's growing in a large container.

  5. So if you are growing say, beans, you must pollinate each individual bean when it appears as a flower, yes?

    1. That was supposed to say they can pollinate themselves because they contain BOTH the male and FEMALE parts within each flower!
      (Darn you auto-correct haha)

      If you are having lots of flowers and no beans.. Then you may want to try the method above for hand pollinating bisexual plants. However, it isn't necessary for most bean plants! Hope that helps!



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