Nothing beats a juicy, home grown tomato! But trying to grow tomatoes during Oklahoma’s hot summers can be a bit demoralizing. The plants start producing in June, but as soon as the really hot weather arrives in July and August, the harvest dwindles. It’s not your fault! Tomatoes prefer temperatures under 85 degrees, and many varieties won’t set fruit if we get prolonged temperatures in the 90s and hotter. Here’s some tips to increase your success this summer.
Plant early: aim to get your tomatoes transplanted in April, so they can mature enough to start producing in June. We want to get them in as early as possible, but after the last spring frost, and when the soil has already started warming up. If you plant in May, they won’t hit their stride until mid-summer when it’s already getting hot, and you’ll miss your best window for production.
Plant deep: if you partially bury a tomato plant, it will send out roots all along the stem. More roots makes for a stronger, more drought tolerant plant. Dig a deep hole, or make a shallow trench and lay the plant on its side, angling upwards. Make sure the trench is at least 6” deep. Toss some compost or worm castings in the soil or trench, then plant so most of the stem is buried, with just the leafy portion of the stem above the soil.
Mulch! If you put down a thick layer of straw mulch or compost, the soil will stay cooler, you won’t have to water as often, and the plants will be less stressed. Mulch also discourages weeds.
Watering: during hot spells, you’ll need to water more often. A deep soak once or twice a week is better than a daily light watering. We’re aiming for the water to reach the root system, not just the soil surface. Overwatering will suffocate the plants’ roots. Poke your finger in the soil to see if it is moist in the root zone. If it is, then it doesn’t need more water.
You can harvest the tomatoes once they show color, but before they fully ripen. They’ll continue to ripen after you pick them. This is especially useful if birds are pecking holes in your one-more-day-until-they’re-ripe tomatoes.
Plant heat tolerant varieties. In my experience, all tomato varieties will have reduced yields during really hot weather, but some do better than others. Juliet is the most heat tolerant variety I have grown, although not the most flavorful. Cherry tomatoes often do better than slicing tomatoes during hot spells. The varieties for sale here are the ones that have done the best for me. One exception; this is the first year I have grown Indigo Cherry Drops, but they come highly recommended and I’m eager to see how they do.
If you keep your plants as healthy as possible, they’ll get back to growing and producing fruit once the heat wave passes.