Every summer, someone I know has more zucchinis than they know what to do with. Zucchini is easy to grow and who doesn’t love the taste and nutrition. But once in a while, zucchini plants seem to rebel. They spend weeks growing and then put out lovely orange flowers but then…nothing. No zucchinis. There are several causes for this.
Flowers Have Gender
Zucchini plants produce both male and female flowers. They look very similar but the females have what looks like a miniature zucchini just below the bud. There are times, such as early in the growing season, when zucchini plants produce only one gender of flowers, usually male. Without both genders present at the same time, pollination cannot take place. As the season progresses, the plant will likely begin to produce both types.
Season and Weather Effects
Environmental effects can influence the development of flower gender. Fluctuations in temperature, changes in the length of the day and changes in the season can impact flower development. The age of the plant and hormones can also play a role.
The presence or lack of bees and other natural pollinators is critical to fruit production. If the area is experiencing low bee populations or climate conditions which effect bees such as cool temperatures or excessive rain, then pollination cannot take place.
What to Do
There is little the home gardener can do if the plant is not producing both flower genders. If the lack of zucchini is due to a lack of pollinators, manual pollination can be attempted. This requires peeling the petals back on the male flowers to expose the anther. Place the anther indirect contact with the center of the female flower and rub the two together. One male flower can be used to pollinate 2 or 3 female flowers.
If female flowers are developing bu have not opened yet, the male flowers can be stored in either a vase or in a moist paper towel in the refrigerator for 3 or 4 days. This can buy you a few days until females open and preserve the males so they don’t die before the females are ready.
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