How to Grow the Best Tomatoes in Arizona
For successful home-growing in Arizona, follow these climate-specific rules.
By John Roark
“Only two things money can’t buy. That’s true love and homegrown tomatoes.” So go the lyrics of a song recorded in 1983 by folk singer Guy Clark.
As it turns out, many gardeners are also passionate about the ripe red fruit when it has been planted, nurtured and harvested with their own hands.
They don’t call them “love apples” for nothing.
“Once you’ve bitten into a tomato that you didn’t buy from a store, you’re spoiled for life. Nothing else will do,” says grower Gregory Ware, who teaches classes on caring for the fruit specifically in our arid region. “Tomatoes aren’t difficult to grow here in Arizona; doing so just requires a different mindset. The usual rules don’t apply. There is no other climate like ours in terms of heat, dryness and soil alkaline levels. If you are from anywhere else in the country, the best advice I can give you is to forget everything you know.”
In the Valley of the Sun, February is the ideal month for starting your tomato garden to get maximum harvest before temperatures escalate. “Once we hit the 95-degree mark, most tomato plants stop being able to set fruit,” Ware says. “Get your seedlings planted early so that the fruit ripens before the heat hits.” Here, Ware shares a few tips on successfully growing your own tomatoes at home.
Tomato plants fall into two growth-habit categories: determinate (or “bush”) and indeterminate. In the case of the former, the height of the mature plant—generally 3 to 4 feet—is controlled by genetics. An indeterminate plant will grow indefinitely, reaching heights of 6 feet or more, until killed by disease or frost. “Due to our abbreviated growing season, the best choice for Arizona growers is determinate,” Ware advises. Look for sturdy, compact seedlings approximately 4 to 6 inches tall with healthy green leaves and no fruit. The presence of fruit signifies an older plant. “Younger plants establish better,” Ware adds.
Seedling packaging may also bear a DTM number, signifying days to maturity, or the approximate amount of time you can expect from planting to picking your first tomato. For species to be grown in Arizona, this number should be in the ‘early’ range of between 50 to 70 days. Plant by mid-February, and you should have fruit before it gets too hot. “I recommend getting ‘early’ or ‘very early’ varieties to avoid complications due to hot weather,” Ware says. “They will tend to blossom, set and bear prior to the heat of summer.”
SOIL AND SUNLIGHT
“If you don’t prepare the soil for in-ground planting, your seedlings will never make it,” Ware cautions. “You can sing love songs to them and dance beneath the full moon, but nothing is going to make them grow.”
Prepare the soil by adding a combination of fertilizer, sulfur and 4 inches of organic matter, such as mulch, compost or peat moss. “Follow directions on the fertilizer bag and sprinkle the fertilizer and sulfur (2.5 pounds per 100 square feet) on top of the soil,” Ware instructs.
In order to flower and grow fruit properly and achieve maximum results, plants should receive a minimum of 6 hours of sun per day. If they are planted in full sun, cover plants with 30% to 50% shade cloth—available at most garden centers—beginning in June, before temperatures climb.
“Tomatoes don’t like huge swings in moisture, either being too constantly wet or too dry between waterings,” Ware says. “Thoroughly water established plants when the top 1 inch of soil is between damp and dry, the way a wrung-out sponge would feel.”
Tomatoes will fare better in the ground than in pots, Ware says, but success can also come to the balcony-bound. “One of the mistakes people make when cultivating tomatoes in containers is choosing an indeterminate plant that’s going to grow very tall and not bear much fruit. Determinate plants are better due to their compact, bushy habit.” Select a pot that matches the size of the plant upon maturity. For example, if you have a plant that’s going to grow 2 feet high by 2 feet wide, your container should have the same dimensions. Potted plants need a minimum of 6 to 8 hours of daily sunlight for best results.
Ware stresses that locally grown plants are the best option for Arizona gardeners. “Support your neighborhood nursery,” he says. “Plants sold in retail chains may come from greenhouses in Colorado, California or Mexico and grown in an environment not remotely like the climate in Arizona. There’s going to be an acclimation period for these plants that could set them back. If they’re started here out in the open, they kind of know what they’re in for.”
DON’T GIVE UP
One of Ware’s most important tips is to not get discouraged. Have fun, he says. “If you run into trouble, consult your local nursery professional. You can grow great tomatoes here. Once you get the hang of it, you’ll wonder why you ever thought it couldn’t be done.”