Tomatoes Not Producing? Here’s Why

by Lydia Holley May 30, 2022

Master Gardener Sherry Sorrell reminded a group of gardeners that the harvest from tomato plants this year may be a bit iffy. The reason? The weather.

This spring has been hot, with temperatures in the high 90’s. Although tomato plants have a reputation for loving heat, they often do not set fruit if temperatures are too high. When temperatures reach 90 degrees F during the day or over 70 degrees F at night, pollen becomes sticky. Tomatoes are generally pollinated by air movement, but those temperatures make the pollen unviable. When relative humidity is too low, that also affects viability. So, hot, dry weather like what we are experiencing can be the cause of tomato plants dropping their blossoms and not setting fruit. Unfortunately, it has been hot and dry most of the spring.

Tomato plants only have 50 hours in which to be pollinated or their blossoms drop, so temperatures only need to be that high for a few days to impact your harvest. But you can always hope for a few days of moderate temperatures.

Besides wishing, what can you do about it? Maybe something, maybe nothing. It is worth trying shade cloth to protect the plants from high daytime heat. Studies have shown this may increase yields by up to 15%. However, if nighttime temperatures are too high, applying shade cloth may not have any benefit.

Sorrell also reminded the gardeners that this information, as well as information on combating blossom end rot, can be found in the Monthly Gardening Guide published by Henderson County Master Gardener Association (HCMGA). Monthly Gardening Guides will be available at the Grand Opening of HCMGA’s newest project, the Harvest Garden, on Thursday, June 2. The public is invited to come to this free event anytime between 4:00 p.m. and 7:00 p.m. The Harvest Garden is located within the Henderson County Regional Fairpark Complex, 3356 TX-31 BUS, Athens.

For more information, call 903-675-6130, email [email protected].