Tomatoes are claimed to be the most popular garden vegetable. More than 35 million gardeners in the US grow their own tomatoes. And with world production at 170 million tons, they have become the world’s most popular fruit, surpassing bananas, apples and oranges. Some people believe the reason is the versatility in ways to eat them, some say it is the flavor or the beauty. But one thing is for sure: you can’t buy a tomato that tastes as good as a ripe one fresh from the garden. As the Guy Clark song goes: “Only two things that money can’t buy; and that’s true love and homegrown tumatuhs.” The poor taste and lack of sugar in commercial tomatoes is both the result of breeding for uniformly red fruit and the fact that they are picked green so they don’t bruise in shipping.
The tomato plant, Solanum lycopersicum, is a member of the nightshade family, along with potatoes, peppers, eggplants and tobacco.
Tomatoes originated in the wild in Peru and Ecuador where they looked more like berries. In fact, the tomato is a big berry. Since it develops from the ovary at the base of the flower and contains the seeds, it is technically classified as a fruit. The Aztecs and other indigenous peoples began cultivating the tomato a couple thousand years ago, but in the 1500s when the Spanish took seeds back to Europe, many people thought it was too much like Deadly Nightshade and were afraid to eat it. For 200 years it was mostly grown as an ornamental. The famous English herbalist, Gerard, described it as “beautiful, but poisonous.” The Puritans brought it to America, but people were afraid to eat it until the late 1700s when Colonel Robert Johnson ate a large quantity of tomatoes in front of a crowd of “thousands” who assumed he would die, but of course, he didn’t. The French had early insights into the tomato. Either because the early tomatoes were heart-shaped, or because they knew or wished the tomato had aphrodisiac qualities, they called it pomme d’amour, Love Apple.
Today there are 13 species of tomatoes and thousands of varieties: Wikipedia says 7500, others say 10,000 and the US Dept of Agriculture says 25,000 varieties. Even our nursery grew 79 varieties this year. Why so many? There are flavors for every palette, a great variety of sizes and textures; there are early and long season, and there are cool weather and heat tolerant varieties. People often ask us, What is the best variety? I like to say, Always plant at least 3 varieties, because last year’s best may not be this year’s best. Jane Shellenberger, in her local classic Organic Gardeners Companion, says “I always factor in that one of my tomato plants may succumb to some type of wilt or disease, in which case I just pull it out and dispose of it with no regrets (but not in the compost pile.)”
People often judge their thumbs to be green or black by how they grow tomatoes. Jane Shellenberger writes, “…success depends on timing, the weather and the varieties you choose.” She and my wife, Eve (whose thumb is emerald green) both say one key is growing in soil that is rich in organic matter, namely a good compost. Eve also uses a good organic fertilizer and mycorrhizae (beneficial fungi) when she plants. She lays the plant in a horizontal position so the buried stem will grow more roots and be near the surface for optimal oxygen and heat. She plants in a mini-greenhouse device called a Solar Cap, that allows planting a month earlier, protects the young plant from wind, keeps the plant and soil warm at night and holds moisture and humidity while the seedling is rooting. This is especially helpful in our erratic spring weather. Eve sets up her Solar Caps a week before planting to pre-warm the soil. It should be safe to plant without protection after May 10th, but isn’t always. Too much heat can also be a problem and Carol O’Meara, tomato expert at Boulder County cooperative extension, says if these hot summers continue, it may be best to plant tomatoes where they get partial shade or cover them in summer with a light shade cloth. Regular watering is also very important for tomatoes and drip irrigation is one of the best methods because it doesn’t splash water on the leaves, reducing the chances of disease, and is more dependable than most humans. Put a dripper on two sides of the plant.
Tomatoes can get big, so how do you support them? I often will use a big tomato cage or a sturdy metal grid or a tripod. Eve likes to use a 6′-7′ tall frame with an open bamboo lattice ceiling, where strings can be attached and will hang down to the growing stems. She wraps the strings around the stems and continues to wrap them as they grow. This system prevents broken stems and provides space to pick and have good air circulation and light. She also starts pruning back the new shoots once she has a good crop of green tomatoes coming on. This pruning is not severe, but enough to keep the plant from becoming huge and also directs more energy into fruit development and less into making vines.
GMO, grafted, determinate, indeterminate, heirloom, hybrid. Why does gardening have to be so complicated? Because Nature is extremely diverse and humans just can’t leave well enough alone. Thankfully the only commercial GMO tomato fizzled out. Grafted tomatoes are claiming some success, especially with varieties that are disease-prone or unproductive. We are watching but have no personal experience yet. Determinate tomatoes are bush varieties that ripen in a concentrated period of time. These usually do not need staking or pruning and can be grown in containers. Indeterminate tomatoes are vining varieties that grow and produce until frost. They need support and pruning speeds ripening and increases fruit size. Hybrid tomatoes are crosses between two varieties, often with certain improvements over both, but the seed will not be the same as the parent. Heirloom tomatoes are open-pollinated, meaning the seed can be saved year after year if they are not pollinated by another variety. These have often been saved for years if not generations because they are successful and especially good.
How can you learn which varieties taste good and are successful in your area? Compare notes with your friends and neighbors, join a garden club, try a couple new varieties every year, and come to the Taste of Tomato. 2017 will be the 7th year that Boulder County Cooperative Extension and Harlequin’s Gardens have hosted an opportunity to taste and compare and vote on 70-100 varieties of tomatoes. Also available at the event are Master Gardeners with expert advice, Service-in-Action sheets explaining how to deal with tomato pests and diseases, and a record of which varieties have been most consistently successful. There is also a demonstration of how to save your own tomato seeds.
Tomatoes come in a wide range of colors: red, yellow, pink, orange striped, and green, so they can be beautiful. They can be eaten in many ways: fresh off the vine with salt, sliced in salads and sandwiches, cooked into sauces, paste and ketchup, grilled, juiced and fried. They can be canned, frozen and dried. And they are good for you. Tomatoes are high in potassium, fiber and Vitamins C, E, K and A. Even though some, especially some cherry tomatoes, can be very sweet, they are not bad for you. Jo Robinson in her book, Eating on the Wild Side, says, “Because tomatoes are a low-glycemic fruit, the higher amount of sugar in small tomatoes is not enough to raise your blood sugar.” Tomatoes are also known to be valuable for their content of the powerful antioxidant “lycopene” which some people believe reduces the risk of heart disease and some cancers and supports prostate health. Robinson says that the smaller tomatoes are higher in nutrition in general and specifically contain more lycopene, especially the currant tomatoes which can have 40 times more lycopene than beefsteak tomatoes.
Every year in the garden is different, and Colorado weather can be challenging, but growing your own tomatoes can be extremely satisfying and rewarding. And if you grow more than you can eat, homegrown tomatoes are always a welcome gift.