Keeping Tomatoes Healthy in Hot Weather (2024)

What a summer it has been so far. Early on the heavy rains provided many challenges for the tomato grower. Now we are in a heat wave with more heat to come. Contrary to what many think, tomatoes are not heat lovers. They much prefer 75 to 95. When temperatures get too hot during the day (over 85 degrees) or are too hot overnight (over 70 degrees) many vegetables including tomatoes and peppers will drop their blossoms. This will cause a noticeable drop off in harvest in a few weeks. I have noticed this effect in my garden:

• Tomatoes – heirloom and large slicing varieties affected more often than cherry tomato types. New cultivars of heat resistant tomatoes have been developed for southern climates.
• Peppers – bell type peppers more affected than hot chili type peppers. Peppers seem more sensitive than tomatoes to this.
• Eggplant, squash and legumes can also be affected.

There are a few things that the backyard grower, community gardener and urban farmer can do to mitigate this harvest loss:

• Mulch around plantings to cool the soil and conserve soil moisture. Organic or non-organic mulch can be used.
• Water deeply and completely at the root zone. DO NOT overhead irrigate.
• Plant multiple tomato varieties to ensure a harvest. Research the use of heat-tolerant cultivars.

CLICK HERE for a Tomato Blossom Drop Fact Sheet