Growings On: How do we go from flower to fruit?

Published 8:00 am Wednesday, July 26, 2023

Some insects are pests but some are very beneficial. When it comes to our vegetable plants, some will self-pollinate and produce on their own but others must have pollinating insects to carry the pollen from plant to plant in order to produce.

For example, leafy vegetables like lettuce don’t need insects since they don’t actually produce fruit. Beans, okra and tomatoes are all self-pollinating, so they don’t need any help developing fruit either. However, when it’s hot (above 90 degrees) and humid the pollen will become sticky, reducing fruit production on our beans and tomatoes.

The cucurbit family, cucumber plants and relatives like pumpkin, honeydew, cantaloupe, watermelon and all types of squash and gourds must have pollination by bees and other insects before they produce any fruit. The whole cucurbit family of plants will produce separate male and female blooms on the same plant. The male blooms will appear a few days before female blooms, and during unfavorable conditions the male bloom can abort before the female bloom has time to be pollinated. Bloom drop commonly occurs during cool weather, when the temperature dips to 55 degrees at night, and/or during periods of heavy rain. Insects typically don’t pollinate during this type of weather, as it’s too cool or wet for them to be out.

Even with perfect weather, gardeners can accidentally disrupt their plant’s pollination with untimely pesticide use. Avoid spraying and dusting insecticides when bees are present, most often in the mornings, and avoid spraying the insecticide on the blooms altogether.

If you notice that many of your vegetable plants are dropping blooms even though they are seeing a lot of bee activity, the problem might be caused by adding too much nitrogen fertilizer too early in the season. Excess nitrogen fertilizer can also cause excess green growth with no flowering at all.

If you have any questions, feel free to contact Brenda Jackson at Murray County Extension at (706) 695-3031 or bljack@uga.edu.