Start with the right variety for your climate and what you want to eat

The tomato you buy at a supermarket in January and the one you grow in your garden are often different plants bred for different reasons. Store tomatoes are bred to ship without bruising and sit on shelves for weeks. Garden tomatoes can be bred for flavor, disease resistance, or the specific number of days your growing season allows.

Before you buy seeds or seedlings, know your first frost date and your last frost date — these define your growing window. The USDA Hardiness Zone Map and your local cooperative extension office both have this information free. Once you know how many frost-free days you have, choose a variety that matures within that window. A tomato that needs 85 days to fruit will not produce if your season is only 70 days long.

Heirloom and open-pollinated varieties like 'Brandywine', 'Cherokee Purple', and 'San Marzano' are known for strong flavor but often need longer seasons and more disease management. Hybrid varieties like 'Early Girl' and 'Celebrity' mature faster and resist disease better, though some gardeners find them less flavorful. Cherry tomatoes like 'Sungold' produce heavily and taste sweet even in short seasons. Paste tomatoes like 'Roma' are meaty and low in juice — good for sauce, less good for eating fresh.

Key Takeaways

  • Choose a variety that matures within your frost-free growing season, which you can find through your USDA zone or local extension office.
  • Plant seedlings or seeds after your last frost date, in soil that has warmed to at least 60°F, ideally 70°F or warmer.
  • Tomatoes need at least six to eight hours of direct sun daily, consistent water (about one inch per week), and soil rich in organic matter.
  • Prune suckers on indeterminate varieties to direct energy into fruit rather than leaves, and stake or cage plants early to prevent root damage later.
  • Watch for common pests and diseases like hornworms, early blight, and powdery mildew, and remove affected leaves or plants promptly to stop spread.

Plant at the right time in soil that is warm enough

Tomatoes are warm-season plants. Planting them too early — when soil is still cold from winter — will stall them or cause the seeds to rot. Wait until after your last frost date and until soil temperature reaches at least 60°F, ideally 70°F or warmer. A soil thermometer costs a few dollars and takes the guesswork out. If you are buying seedlings from a nursery, harden them off first by setting them outside in shade for a few hours, then gradually increasing sun exposure over a week, before planting them in the ground.

Dig a hole slightly deeper than the root ball of your seedling. Tomatoes can develop roots all along their buried stem, so you can plant them deeper than they were growing in their pot — bury the stem up to the first true leaves if the plant is leggy. Space plants 24 to 36 inches apart depending on the variety; check the seed packet or plant label for the specific spacing.

If you are starting from seed indoors, sow them six to eight weeks before your last frost date. Tomato seeds need warmth to germinate — a heat mat set to 70–75°F speeds germination to five to ten days. Once seedlings emerge, they need bright light, ideally from a grow light positioned a few inches above the leaves, for 14 to 16 hours daily. Without enough light, seedlings become tall and spindly.

Give tomatoes sun, consistent water, and rich soil

Tomatoes need at least six to eight hours of direct sun daily — more is better. In very hot climates (above 95°F regularly), afternoon shade can prevent sunscald on fruit, but most gardens benefit from full sun. Poor light produces fewer flowers and smaller fruit.

Water deeply and consistently. Tomatoes need about one inch of water per week, including rain. Water at the soil level rather than overhead; wet leaves invite fungal disease. Water in the morning so any splash dries quickly. Inconsistent watering — dry spells followed by heavy rain — causes blossom-end rot (a dark, sunken spot on the bottom of the fruit) and fruit cracking. Mulch around the base with two to three inches of straw or shredded leaves to keep soil moisture steady and prevent soil from splashing onto leaves.

Tomatoes are heavy feeders. Before planting, work compost or aged manure into the top six to eight inches of soil. If your soil is poor, add a balanced fertilizer like 5-10-10 or 10-10-10 at planting time. Once plants are flowering, switch to a lower-nitrogen fertilizer (like 5-20-20) to encourage fruit rather than leaf growth. Follow the package directions for how much and how often. Overfertilizing with nitrogen produces leafy plants with few tomatoes.

Stake or cage plants early and prune suckers on indeterminate types

Tomatoes come in two growth habits: determinate and indeterminate. Determinate varieties grow to a fixed height (usually three to four feet), produce most of their fruit at once, and are good for canning. Indeterminate varieties grow continuously throughout the season, producing fruit until frost, and can reach six feet or taller. Check your seed packet or plant label to know which you have.

Install stakes or cages at planting time, not later. Driving a stake through the root system of an established plant damages roots and invites disease. For indeterminate varieties, use a sturdy stake (at least six feet tall) or a tall cage, and tie the main stem loosely to it as it grows, using soft ties like cloth strips or tomato clips. For determinate varieties, a four-foot cage usually suffices.

On indeterminate varieties, remove suckers — the shoots that grow in the angle between the main stem and a branch. Suckers produce leaves but no fruit and divert energy from flowering. Pinch them off by hand when they are small, or cut them with pruning shears. On determinate varieties, pruning is less critical because the plant naturally stops growing. In very hot climates, some gardeners leave a few lower leaves on indeterminate plants to shade developing fruit from sunscald.

Watch for pests and diseases, and remove affected parts quickly

Tomato hornworms are large green caterpillars that can strip a plant of leaves in days. Check the undersides of leaves weekly and hand-pick them, or spray with Bacillus thuringiensis (Bt), a naturally occurring bacterium that kills caterpillars but is safe for other insects. Aphids, spider mites, and whiteflies also attack tomatoes; a strong spray of water from the hose can dislodge many of them, or use insecticidal soap if the infestation is heavy.

Early blight appears as brown spots with concentric rings on lower leaves, usually starting mid-season. Powdery mildew looks like a white powder on leaves. Both spread in humid conditions and poor air circulation. Remove affected leaves as soon as you see them — do not compost them, throw them in the trash. Space plants far enough apart that air flows between them. Water at soil level, not overhead. If disease persists, spray with sulfur or a fungicide labeled for tomatoes, following the label directions and the harvest waiting period.

Blossom-end rot is a dark, sunken spot on the bottom of the fruit, caused by calcium deficiency linked to inconsistent watering. It cannot be fixed once it appears on a fruit, but consistent watering prevents it on future fruit. Remove affected fruit so the plant directs energy elsewhere.

Harvest tomatoes at the right stage and store them correctly

Tomatoes develop flavor as they ripen, but they also ripen off the vine. Pick tomatoes when they are fully colored but still slightly firm — they will soften over a few days at room temperature. If frost is coming and you have green tomatoes still on the vine, pick them and set them on a windowsill indoors; they will ripen slowly over weeks.

Store ripe tomatoes at room temperature, never in the refrigerator. Cold breaks down the cell walls and makes them mealy and flavorless. Keep them out of direct sun, which can soften them too quickly. A tomato at peak ripeness lasts three to five days at room temperature before it begins to decline.

Frequently Asked Questions

Why are my tomato flowers dropping without making fruit?

Flowers drop when temperatures are too cold (below 55°F at night) or too hot (above 90°F during the day), when watering is inconsistent, or when nitrogen fertilizer is too high. Check your watering schedule first — tomatoes need steady moisture. If temperatures are the problem, wait; flowers will set fruit again when conditions improve.

Can I grow tomatoes in a pot?

Yes. Use a pot at least five gallons for determinate varieties and ten gallons for indeterminate varieties. Fill it with potting soil (not garden soil), water it regularly because pots dry out faster than ground, and fertilize every two to three weeks because water drains nutrients away. Pots in full sun heat up quickly, so water more often in hot weather.

What does it mean if my tomato leaves are turning yellow?

Yellow lower leaves are often normal as the plant matures and sheds old growth. Yellow leaves higher up can signal nitrogen deficiency, overwatering, or disease. Check the soil — it should be moist but not soggy. If the soil is wet and leaves are yellow, reduce watering. If soil is dry, water more. If yellowing spreads rapidly or appears with spots, it may be disease; remove affected leaves.

How do I know when to stop watering before frost?

Keep watering until frost arrives. Stopping water early stresses the plant and can actually trigger early ripening of remaining fruit, which may not have time to mature. Water normally right up until the first frost date in your area.

Do I need to prune determinate tomatoes?

Determinate varieties do not require pruning the way indeterminate ones do. You can remove lower leaves once fruit sets to improve air circulation and reduce disease, but heavy pruning is not necessary. Focus on removing any diseased or damaged leaves.