If you bring home a tomato plant this time of year, there are a few things to consider before you plant it.
On television the other day, someone was talking about summer being almost here. I chuckled, as I looked at the thermometer on the patio and saw the temperature was over 100°. I knew then I wasn’t watching a locally produced show.
Going into a nursery or a home store around town, there’s the same kind of craziness. When we should be looking for ways to increase shade and conserve water, people are trying to sell us little tomato plants, which probably aren’t going to do well at all! The plant will grow, as long as it receives ample water, but it’s not likely to produce fruits. Tomatoes tend to get unhappy when temperatures go much above 85 or 90 degrees.
For one thing, the pollen, which fertilizes the flowers, dries out in the heat. With less fertilization, there will be many fewer fruits. Even when fruits do develop, if they stay on the vine during blistering hot, bright sunny days, they’ll cook, and not well.
The red color compounds can’t form in high temperatures, and even the chlorophyll in the green fruits gets destroyed. What you wind up with are scorched, greenish, and poached – not attractive, and not tasty. To save the yield, don’t wait until they’ve reddened on the vine. Once they’ve started to turn orange, harvest them and put them on the window sill. They might not be as fabulous as any that ripened on the plant, but they’ll be a lot better than if they’ve baked outside.
This is one reason I tell people to think of tomatoes for late spring, not summer.
When it gets really hot in July, consider cutting the plant down to just a few inches, watering and mulching it. Come September, it’ll start producing more tomatoes.
Still, we want to grow something, even if temperatures are severe. The situation isn’t desperate; there are plants that’ll grow merrily throughout the summer, and produce delicious fruits.
Think about melons.
Melons and pumpkins, both members of the same family, tolerate high sunlight and heat terrifically well. Cantaloupes just bask in the sun. As long as they never dry out, they’re delighted. This is one time when you absolutely want to maintain a layer of mulch – straw, chipped wood, anything organic – to keep the soil moist, but not wet.
They also need pretty rich soil with higher levels of phosphorus and potassium.
If you look at a fertilizer container, you’ll see three numbers. The first one represents the percentage of nitrogen, which is essential for green leaves. The second number’s the percentage of phosphorus – this is necessary for roots, as well as anything the plant needs for reproduction; flowers and fruits are how the plant reproduces.
The third percentage is potassium, the necessary element for moving water and sugar from leaves to the fruits. Look for higher second and third numbers.
Melons and squash aren’t foolproof, and intrepid desert gardeners will probably face a couple of problems.
One is powdery mildew. This is a fungus, and it looks as if someone spilled talcum powder on the leaves. If you see something like this, and you can’t just blow the powder off, you’re likely dealing with powdery mildew. On the one hand, it doesn’t kill the plant, but it does interfere with photosynthesis, and lowers the amount of sugar the plant can make. You can treat the problem, but not cure it, by washing the leaves with soapy water and rinsing them off.
If you get them, squash bugs are a nightmare. These are hard to control after they’ve appeared. Remove and kill any you see. Try some of the insecticidal soaps and wash the plants thoroughly. Not perfect, but better than no treatment at all.
If you can keep the plants relatively healthy, you’ll have delicious melons, even in the middle of our astonishingly hot summer! Pumpkins are slower, but you’ll harvest them just in time for Halloween!
For KNPR’s Desert Bloom, this is Dr. Angela O’Callaghan of the University of Nevada Cooperative Extension.
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