Choosing: When buying a six-pack of seedlings to transplant to your garden, look for clean, dark green foliage and a sturdy habit. If the bottom leaves are yellow or flowers are present, the plant is stressed. Check also for aphids and other pests. The healthiest, most productive plants start out unstressed and pest-free. Picking a few varieties from among the hundreds available is a real challenge. We've named a few best bets below. But before you even look at a variety, you have a few choices to make.
Heirlooms vs. hybrids. Heirlooms are often not as productive as hybrids, but they typically taste better and you can save their seeds from one season to the next, eventually breeding a variety that is perfectly suited to your conditions. Most heirlooms are "indeterminate" types, meaning they grow long, sprawling vines and produce tomatoes continuously through the season. Hybrids, on the other hand, often have disease-resistance that heirlooms lack. You can tell what diseases a hybrid can withstand by the letters after its name on the plant tag. For example, VFFNTA means the plant is resistant to Verticillium wilt, Fusarium races 1 and 2, root knot Nematodes, Tobacco mosaic virus, and Alternaria stem canker. That's a good choice if diseases have knocked out your tomatoes in the past.
Early start. To extend your tomato-harvesting season, plant one or two early-ripening varieties. These are often "determinate" types, meaning they produce all at once and have shorter, less rangy vines.
Planting Don't rush to plant. Getting a tomato plant into the ground when the soil is cold causes it to turn purple (purple foliage means the plant can't take up phosphorus). Wait a week or two after the average last-frost date. Plant deep, up to the first set of leaves. Tomatoes develop adventitious roots—roots that originate from the buried stem. A bigger and broader root system helps the plant support a heavy load of fruit. Space plants about 3 feet apart, unless you're using the stake-and-weave support system.
- Well-drained. If the soil stays soggy where you want to plant, build a raised bed.
- Sunny. Tomato plants need at least 8 hours of sunlight a day, or they get spindly and produce little mature fruit.
- Fresh. Most tomato diseases reside in the soil and affect peppers, eggplants, potatoes, and other related crops also. To break the disease cycle, starve the disease-causing organisms by rotating the vegetables with unrelated ones, such as beans or lettuce.
Making Your Bed Tomatoes grow best in slightly acidic soil (pH 6.2 to 6.8). If you suspect your soil isn't, get a soil test and amend accordingly. Two ways to ensure that your tomato bed is full of beneficial soil organisms and plant nutrients:
Add compost. Fork the soil to a depth of 1 foot and add two shovelfuls of compost to each planting hole. This improves drainage, increases soil fertility, and helps the soil hold water.
Grow a cover crop. Plant a grain or legume crop—sometimes called green manure—for the purpose of chopping it down and adding it to the soil. One tried-and-true way is to plant hairy vetch (a nitrogen-fixing legume) in your garden bed in fall. In spring, cut it down and plant your tomatoes in holes you carve through the matted residue and stubble. This provides both nitrogen and an instant mulch that preserves moisture and keeps weeds from sprouting.
Food and Water Fertilizer. Don Boekelheide, our test gardener in Charlotte, North Carolina, scratches a 5-3-3 organic fertilizer and a handful of rock phosphate into the soil around his tomato plants twice during the growing season—once when the plant is a foot tall, and again when it flowers. Spraying your plants with a fish emulsion or kelp solution two or three times a season also boosts vigor, which helps the vines outgrow diseases.
Water. Give your plants an inch of water each week when it doesn't rain to prevent fruit from cracking or developing blossom-end rot. The most efficient method is a drip system or inexpensive soaker hose.
Weed Control Mulch suppresses weeds and conserves moisture. Any mulch is better than none, but a comparison study done by the USDA in Beltsville, Maryland, showed that tomatoes mulched with mown vetch (see "Grow a Cover Crop," above) produced especially robust root systems and outperformed those mulched with plastic. We recommend a 3- to 4- inch layer of dried clippings, leaf mold, straw, or even shredded newspaper—all of which decompose and feed soil organisms—over plastic. Clear or IRT (infrared transmitting) plastic mulches make sense where summers are short, because they warm the soil.
Companions Tomatoes love carrots. And onions, and basil, and marigolds. A neat row of 'Summerlong' basil or triple curled parsley looks nice and makes for an efficient use of space. West Coast Contributing Editor Willi Evans Galloway used the shady spot created by her tomato plants as a nursery bed for lettuce seedlings in her Seattle garden last summer.
Support Systems Stake or cage plants while they are small, so you don't damage branches or roots. At the Organic Gardening Test Garden, we found these methods effective:
Concrete-reinforcing-wire cages: We build them 5 feet high and 2 1/2 to 3 feet in diameter. The welded steel mesh supports even the largest plants. Until, that is, they are laden with fruit and a gust of wind whips through. Experience has taught us that weaving 8-foot bamboo poles horizontally through the cages about 4 feet off the ground and tying them to the cages keeps them upright. Debbie Leung, our Washington State test gardener, uses similar reinforcing poles but attaches them to metal T-stakes, driven into the ground between every fourth cage.
Stake-and-weave trellising: The plants are held up between lengths of twine strung between parallel rows of stakes. You can harvest more and earlier tomatoes from a limited area by spacing plants 1 1/2 to 2 feet apart (instead of 3 feet) and pounding a 6-foot stake into the ground between every other plant. As the plants grow, weave baling twine in and out of stakes and tomatoes. Do this 4 to 6 times over the growing season. John Good, of Quiet Creek Farm near Kutztown, Pennsylvania, prefers this method because it ensures good air circulation. It also makes harvesting easier.
Prune or Not? Research by Purdue University showed that pruning (by removing the branches, or "suckers," below the first main stem) increased the average fruit weight in some cases, but not the total yield per plant. Where pruning makes sense: If you stake and weave, prune the lower suckers for better air circulation; if planting in an ornamental garden, prune suckers (see illustration) for neatness. Don Boekelheide (our tester in North Carolina) prunes vigorous indeterminates to two main stems early in the season to keep them from taking over his southern garden.
Hall of Fame Tomatoes When gardeners, foodies, and other tomato lovers gather at taste-offs and festivals to rate the flavor of tomatoes, a few varieties repeatedly show up on winners' lists. To these we've added some of our own favorites.
Hefty Heirlooms 'Brandywine OTV' Big, red, and juicy. An uncontested favorite. 'Caspian Pink' Beefsteak-type tomato with pinkish red fruit. 'Constoluto Genovese' Red ribbed fruit with a classic taste. 'Hillbilly' Yellow and red streaked fruit, beautiful sliced. 'Radiator Charlie's Mortgage Lifter' Each pinkish red fruit can be 2 pounds or more.
Round, Red, and Reliable 'Arkansas Traveler' Good hot-weather producer. 'Carmello' FVNT hybrid with early small to midsize fruit. 'Celebrity' VFFTNA hybrid compact plant with midsize fruit. 'Early Girl' VFF indeterminate, early and dependable. 'Stupice' A winner in the Northwest, where fruit set is a problem.
Non-Red 'Cherokee Purple' Large pink-purple fruit with complex flavor. 'Garden Peach' Small yellow fruit with slightly fuzzy skin. 'Jaune Flamee' Small deep orange fruit. 'Lemon Boy' VFN hybrid with mild yellow fruit. 'Paul Robeson' Midsize dusky dark red fruit; big flavor.
Plum Tomatoes 'Amish Paste' Medium-large red, solid fruits 'Margherita' VF hybrid, compact plant with small fruits that are excellent roasted. 'Speckled Roman' Meaty, striped yellow and orange fruit.
Cherries and Grapes 'Sungold' FT hybrid with yellow fruit. Most wanted cherry tomato. 'Isis Candy' Marbled red-orange fruit. 'Matt's Wild Cherry' Early red cherry/grape prized for flavor. 'Super Sweet 100' VF hybrid with sweet red fruit. 'Cupid' Fast hybrid red grape. Favorite of the OG test garden.
SEED SOURCES Gary Ibsen's TomatoFest, Carmel, CA; 831-625-6041, store.tomatofest.com Johnny's Selected Seeds, Winslow, ME; 877-564-6697, johnnyseeds.com Tomato Growers Supply, Fort Meyers, FL; 888-478-7333, tomatogrowers.com
Common Problems Solved
- Early blight. Caused by a fungus that survives the winter on old vines. Remove and destroy diseased foliage. Avoid crowding and prune for good air circulation. Rotate crops.
- Late blight. Caused by a fungus that is favored by wet weather. Spores travel great distances and infect large areas. Avoid crowding. If the infection is severe and widespread, remove and destroy all affected plants.
- Wilts. Fusarium and Verticillium fungi cause parts of the plant to wilt, and can kill it over time. Look for resistant varieties. Rotate crops. Southern bacterial wilt results in sudden plant death. Remove and destroy all debris, and do not plant tomatoes where the disease has occurred in the past.
- Root-knot nematodes. Caused by microscopic eelworms that live in soil. Look for resistant varieties. Rotate tomatoes with marigolds, tilling the marigolds into the soil at the end of the season.
- Blossom-end rot. Caused by poor calcium uptake due to inconsistent moisture. Provide consistent moisture with a soaker hose, and keep a layer of mulch on the soil.
- Cracking. Caused by sudden summer rains after dry periods. Provide consistent moisture. Look for varieties that are resistant to cracking.
- Catfacing. Caused by incomplete pollination in cold weather. Don't plant too early. Select varieties that resist catfacing.
- Tomato hornworm: Handpick and squash the caterpillars, but spare those that carry the white cocoons of braconid wasps on their backs. The wasps are their natural predators; to attract them, plant dill, and let your cilantro flower.
Master's Tip: Seed crimson clover under tomato plants when they are about 2 feet tall. The clover serves as a weed-smothering "living mulch" while fixing nitrogen into its root nodules.
Newbie Hint: Transplant nursery-bought seedlings into larger pots. Let them size up, and then plant outdoors a week or two after the last-frost date, when the soil is warm.
Health News Eating fresh tomatoes is a tasty way to take in vitamins A and C, but what's gripping the attention of horticultural and health scientists these days is another constituent of the fruit: lycopene, the compound responsible for the red color. Studies at the Harvard School of Public Health, the University of Illinois, and elsewhere have linked the lycopene in tomatoes to a decreased risk of cancer. Breeders have been racing to produce a tomato that has high amounts of this cancer-fighting antioxidant and also retains the classic tomato taste. Coming soon to your area is high-lycopene Fla. 8153, also known by the name 'Flora-Lee', a hybrid developed by Jay Scott, Ph.D., of the University of Florida. It contains 25 percent more lycopene than standard cultivars, it's resistant to tomato diseases, and most important, it tastes like a tomato should.