By Richard Jauron, Kendall Evans
The summer months are the perfect time to enjoy homegrown fruits and vegetables. With varying weather and temperature, maintaining healthy fruit and vegetable plants can sometimes be a struggle. Here are some tips from Iowa State University Extension and Outreach on how to properly maintain fruit plants in the summer months to ensure a high fruit production, with help from ISU Extension horticulturists. To have additional questions answered, contact the ISU Hortline at 515-294-3108 or at hortline@iastate.edu.
My cucumber plants are blooming heavily, but aren’t producing many fruit. Why?
Cucumbers and other vine crops are monoecious. Monoecious plants have separate male and female flowers on the same plant. Male and female flowers are similar in appearance. However, the female flowers have small, immature fruits at their base. Pollen is transferred from the male to the female flowers by bees and other pollinators.
When properly pollinated and fertilized, the female flowers develop into fruit. The first flowers to appear on cucumbers and other vine crops are predominately male. As a result, fruit production is poor when the vines first begin to flower. The cucumber vines should start producing a good crop within a few weeks as the number of female flowers increases.
Poor weather and the use of insecticides can also affect fruit set on cucumbers. Cool, rainy weather during bloom reduces bee activity. Fewer bees visiting the garden can result in poor pollination and a poor fruit set. Apply insecticides in the garden only when necessary to avoid harming bees and other pollinators.
My tomato plants are flowering, but aren’t setting fruit. Why?
Unfavorable weather conditions are the primary reason for blossom drop in tomatoes. High daytime temperatures, above 85 degrees Fahrenheit, and low nighttime temperatures, below 55 degrees Fahrenheit, interfere with pollination, causing blossom drop.
Optimal growing conditions for tomatoes are daytime temperatures of 70 to 85 degrees Fahrenheit. Cherry tomatoes set fruit over a wider temperature range than most large fruited tomato cultivars. Strong winds and dry soil conditions may also contribute to blossom drop. Strong winds desiccate flowers, while dry soil conditions stress tomato plants.
Nothing can be done about the weather. Deeply water tomato plants once a week during dry weather. Fruit set should increase when temperatures moderate.
My hot peppers are setting fruit, but not my bell peppers. Why?
In regards to fruit set, bell peppers are more sensitive to temperatures than tomatoes. The optimum temperature range for flowering and fruit set on bell peppers is between 70 and 80 degrees Fahrenheit. Hot peppers tolerate high temperatures much better than bell peppers and often produce fruit in hot weather.