Heat tolerant tomatoes: Growing tomatoes in hot weather

If you want to plant tomatoes during hot weather months try some of those labeled “heat tolerant.” These plant varieties can tolerate the heat and produce pollen and tomatoes when the temperature is above 85 degrees.

Heat tolerant tomatoes will have names like Solar Fire, Phoenix, Heat Master, Summer Set, etc. They are for the most part determinant which means they grow like a bush. Probably my favorite would be the Phoenix although all of those named will be good producers. Use your search engine/Google these heat tolerant names and read a little about each. Here in Southern California, “Bonnie Plants” usually puts out heat tolerant tomato plants beginning about mid-June.

Typically, we plant tomatoes in the springtime once the cool weather has passed and before the hot weather arrives. And typically we get lots of tomatoes as this is the best time of year to plant. Most springtime type tomatoes do not produce pollen until night time temperatures reach about 55 degrees. The plants will grow, blossoms come out, but no pollen until the night time temperature warms up to about 55 degrees. And when daytime temperatures reach about 85 degrees and higher, the tomato plants that we plant in the springtime typically stop producing pollen also. It’s simply too hot and the tomato plant wants goes into survival mode until the hot weather cools back down.

There are also other tomatoes that will tolerate hot weather and still produce tomatoes. For example Sun Gold Cherry tomatoes, Husky Cherry Red, San Diego, and Better Boy also tolerate heat and do pretty well. Realize that when hot weather is consistently over 100/105/110 degrees and higher, even the heat tolerant tomatoes will struggle to survive.

Generally speaking, plant these heat tolerant type tomatoes in May, June, July, August. When planting most any young live tomato plant in summer heat, it will do fine if you keep the roots moist. These young little plants are like little kids out on the playground during a hot day—they don’t notice how how it is until they grow older and mature it seems.     

When you know weather hotter than 85 degrees is in the forecast almost daily, plant these heat tolerant tomatoes. Plant these in hot August and these tomatoes should take you until cold weather comes along. Once nighttime temperatures get below about 50 degrees the tomato plant typically no longer produces pollen which means no more tomatoes and the cold weather will eventually take it out. Planting next to a brick wall, stucco wall, something that absorbs heat all day can radiate that heat back out at night fooling the tomato into thinking it’s plenty warm to keep producing pollen and tomatoes right through the winter. 

A very key note on growing tomatoes especially during periods of hot weather is to make sure you use a potting mix that contains 30% maybe 40% even 50% sphagnum peat moss or peat moss. 1 pound of sphagnum peat moss can hold 20 – 25 pounds of water. Yes, holds water like a sponge surrounding your roots. Exactly what you want. Read the potting mix ingredients label; the No. 1 ingredient should be peat moss or sphagnum peat moss. Read more about recommended soils and potting mixes.

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Dave Freed /  the Tomato Guy