9 Tips for Growing the Biggest, Reddest, Juiciest Tomatoes Ever

Heirlooms — varieties that can be reproduced from their own seed — are the rage right now, particularly among seed collectors like LeHoullier. He estimates there are 10,000 tomato varieties, and, as a member of the Seed Savers Exchange, he has collected seeds for about half of them. Hybrids are a cross of varieties and can't be duplicated from their own seed. They were developed to be more disease- or pest-resistant, VanVranken explains. Both have their advantages, growers say, and there's nothing inferior about hybrids.

3. Match your tomato to your garden

The amount of sunlight tomatoes need depends on their size, LeHouillier says. “The big beefsteak types, those probably do benefit from having six to eight hours of direct sun a day, but as the size of the tomato decreases, the amount of sun it needs to be happy decreases, as well,” he says.

If you get only three hours of sunlight on your patio, try cherry tomatoes in a container. If you’re buying tomato plants, buy locally. Even big-box stores are likely to have purchased plants from regional growers, and plants will be conditioned for your area, VanVranken says.​

4. Go deep

Tomatoes grow roots all along their stems, says Elizabeth Casteel, “the Tomato Lady” of Spokane, Washington, who last year grew 6,000 tomato plants — which she calls her “babies” — that she sells from her barely half-acre home garden. When she transfers seedlings to gallon-size pots, she puts them as low as she can, leaving a couple of sets of leaves above the soil. “I cover up the leaves that are [buried] because they’ll compost ... I don't rip them off,” she says. She tosses in some finely crushed eggshells to provide calcium and prevent damping off, a fungal disease.​

5. Provide support

Garden catalogs and YouTube experts offer all kinds of ways to support tomato vines, from stakes to cages to string to fancy trellises. Rutgers has instructions for a stake and weave system that commercial growers use and that is adaptable for home gardeners who are willing to spend the time. Whatever system you choose, getting plants off the ground can increase your yield by 30 percent because you'll avoid soil-borne diseases, VanVranken explains.

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6. Prune your plants — or not

Too many side shoots crowd fruit, particularly if you’re using cages for support, VanVranken says. And many growers prune off lower branches to avoid leaves that attract pests or fungi from the ground. But if you don’t stake, pruning may be less important, he says, because branches will flop down on their own. Pruning can give your indeterminate plant a strong central stem, prevent it from flopping over and boost production. To achieve this, pinch out the suckers that grow in the "V" between the main stem and an offshoot. Determinate plants require less pruning, and pruning may even reduce the harvest.

Or skip the pruning altogether and just plant more tomatoes, Casteel suggests. In her own garden, she doesn’t bother with pruning. “With 30 plants, I don’t need 500 pounds of tomatoes per plant,” she says.​

7. Water from below

Always water with a drip or soaker hose, rather than a sprinkler, all three growers say. “You don't get as much evaporation, and the water is right where it's supposed to be,” Casteel observes. The goal is to reduce the amount of standing water on the leaves and make them less attractive to pathogens, VanVranken adds.

8. Fertilize mindfully

There are probably as many different tomato-fertilizer philosophies as there are varieties. Be wary of too much nitrogen, VanVranken says, as the plants won't produce the flowers they need to fruit.

Casteel plants her tomatoes in Pro-Mix, a soil with an additive fungi called mycorrhiza that helps plants absorb nutrients. She also adds kelp meal, alfalfa meal, steamed bone meal, worm castings and Epsom salts. “We do our tomatoes organically; however, when I run out of room in the garden, and I need to go into a container, I will use Miracle-Gro [fertilizer],” she says.​

It can be challenging to keep a container plant fertilized, because frequent watering leaches nutrients out. “You really need to do a half-strength [application] every two weeks, or even quarter strength, and that keeps them happier,” Casteel notes.​

9. Go easy on the pest sprays

All three growers stop using sprays once the plant sets fruit. Be on the lookout for the tomato hornworm, a large green caterpillar, VanVranken cautions. If you pay close attention, you can just pick them off before they cause much damage. “Those can do significant damage to a tomato plant and chew on the fruit as well,” he says. “They end up being a great example of how you can get biological control going in your garden.” If you spot a hornworm with tiny white pods sticking out of its back, leave it, he says; the pods are the cocoons of a parasitic wasp, and when the eggs hatch, the larvae feed on the insides of the caterpillar.​

Aphids are another pest. They can reproduce quickly and suck the nutrient-rich liquids out of the tomato leaves. Clemson University Cooperative Extension warns that overuse of nitrogen fertilizer can encourage them. The extension service has a factsheet on aphid control that includes tips ranging from specific mulch to biological controls like lacewing eggs and parasitic wasps.​​

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