Question: Is there something going on this year to explain why my cucumbers, tomatoes and peppers are not producing fruit?
Answer: Weather conditions play a major role in why certain vegetables do not produce fruit, but there are other factors that also play a part in slow or no fruit production.
Cucumbers and other vine crops often have separate male and female flowers on the same plant. Male flowers are produced a week or two before the females and lack the developing fruit at the base of the flower. Sometimes folks don't understand it just takes awhile for female flowers to be produced. Insects are necessary to transfer pollen from the male to the female flowers.
Sometimes, cold, rainy weather during bloom reduces bee and other insect activity. Fewer insects results in poor pollination and poor fruit set. Be careful when you use pesticides in the garden as they can kill pollinators. I like to grow flowers as companions with my vegetables to attract pollinators.
If your plants have female flowers and the fruits still aren't setting, be sure the plants are not excessively dry. Avoid watering too shallowly and too often. Excessive nitrogen fertilization also could be a problem because the plant will produce foliage over fruit. Using compost or organic fertilizer should help. If all else fails, you can manually transfer pollen from the male flowers to the female flowers by hand. Use a cotton swab or soft-bristle paintbrush to transfer pollen.
Unfavorable weather conditions are the primary reason for poor fruit production on tomatoes. High daytime temperatures (above 85 degrees) and low nighttime temperatures (below 55 degrees) interfere with pollination, causing blossom drop or making the pollen not viable. Tomato plants are self-pollinating, meaning the pollen falls within the flower or from flower to flower to pollinate itself.
Tomatoes rely mostly on the wind to pollinate flowers. Insects can help pollinate tomato flowers also. Humidity can also affect pollination. When humidity is high for extended periods, the pollen may become so sticky that it does not fall. In the arid regions, pollen may become so dry that it does not stick to the female part of the flower. Many gardeners try to gently shake the plant occasionally to encourage pollination.
Tomato plants usually will start to produce fruit when the weather becomes favorable. Some experts report that heirloom tomatoes can be even fussier about temperatures than other tomatoes and will not produce fruit until late summer or early fall.
Bell peppers are even more sensitive to high and low temperatures during bloom. Pollination and fruit set typically don't occur when daytime temperatures rise above 85 degrees or when nighttime temperatures drop below 60 degrees. Overly dry soil conditions and windy weather during flowering also can inhibit pollination and fruit set.
Extreme high and low temperatures in our region has contributed to poor fruit production in many gardens. Most vegetables will produce as the season develops.
The Plant Medic, written by Ricky Kemery, appears every other Saturday. Kemery retired as the extension educator for horticulture at the Allen County Purdue Extension Service. To send him a question, email firstname.lastname@example.org.