Hand Pollinating Squash and Pumpkin Flowers

Most of the time, when you plant squash, you have bees that come around to pollinate your garden, including the squash blossoms. However, if you live in an area where the bee population is small, you might have difficulties having squash pollinated unless you do it yourself. To ensure maximum production of your plants, you can hand pollinate your pumpkins and squash by following a few simple steps.

Female flower with small fruit (ovary).

Male flowers lack an ovary.

Hand pollination of squash blossoms requires no special skills or tools. All you have to do is be able to identify male and female flowers. On squash, this is very easy to do. Female flowers will always have a tiny fruit under the flower. Male flowers grow on a long narrow stem. Pictured above are female and male flowers. You can see the presence of a fruit (ovary) at the base of the flower on the female, and the lack of fruit on the flower of the male.

   You can also tell the two apart by looking at the reproductive organs found in the center of the flower. The female flowers contain the stigma. It has several bumpy structures that cluster around a central opening. This  is where you will be applying the pollen when you perform hand pollinating.

Inside the male flower is a slender filament known as the anther. If you touch the anther, you will see that pollen rubs off the anther. This is what makes it so easy to do hand pollinating.

 Cut the male flower off where the flower stem meets the main stem of the plant. Next, gently remove all of the petals from the flower. Once the petals are gone you are left with a stem and exposed anther.

Now find a female flower and use your stem and anther to "paint" the stigma in the center of the female flower. Gently rub the anther over the stigma a few times, as if brushing paint on it. This will be enough to pollinate the stigma, which will then produce squash. Then go on to the next female flower. Each anther can be used to pollinate several female blossoms. However, since there's no shortage of male flowers, we just use one male per female, and leave the anther sitting inside each pollinated flower. This makes it easy to identify which flowers have already been pollinated.

 

 The pollen is being transferred to the stigma of the female flower completing the process of pollination. In nature, bees and other insects perform this important procedure.

After pollination, fertilization occurs and the fruit develops. Fertilization is necessary for fruit formation. If fertilization does not occur, the ovary will wither away. If fertilization is successful, the ovary will begin to swell and a fruit develops.

 

 When you pollinate by hand, realize that you are not wasting flowers since picking the male flowers simply removes those that will never produce a fruit anyway. Only the female flowers can bear fruit, while the males are used for pollination.

After pollination, you can sit back, watch your squash grow and harvest them as they are ready toward the end of summer.