Extension

There’s nothing better than fruits and vegetables picked fresh off the vine, but some gardeners may have plenty of flowers on the plants but little to no fruit. What’s going on?

 

One issue could be that gardeners were a little generous with the nitrogen fertilizer in the beginning of the season. Excess fertilizer encourages leafy growth rather than fruit development. This will delay flowering and reduce the plants’ energy for setting fruit.

 

Irrigation is as important as fertilizing. Crops such as squash, cucumbers and melons are sensitive to inconsistent watering. Both overwatering and underwatering can cause flower drop or an imbalance in the ratio of male and female flowers. Fruit formation is reduced when the plant has a low number of female plants.

 

As we know, Oklahoma summers can be hot. The high temps can affect fruit set. Fruiting vegetables such as tomatoes and squash experience reduced fruit set when the day time temperatures exceed 90 degrees Fahrenheit. Consistent nighttime temperatures above 70 degrees also has an adverse effect on fruit development. In addition, pollen can become sterile at higher temperatures, which prevents fertilization.

 

Gardeners may also be dealing with pest and disease issues. In cucurbits, cucumber beetles, squash bugs and squash vine borers cause direct damage and compromise plant strength. For those who are growing tomatoes, keep an eye out for tomato hornworms, aphids, whiteflies, spider mites, fruitworms, stink bugs and cutworms. These pests stress the plants, cause flower and fruit drop or damage fruit directly, resulting in reduced yields.

 

There are steps gardeners should follow to improve fruit production, including striving for balanced fertilization, consistent watering and pest monitoring. They can also protect plants from excessive heat with shade cloth. However, fruit setting may still be low during the hottest part of the summer.