Start with the right variety for your space and climate

The first choice is whether to grow determinate or indeterminate tomatoes. Determinate varieties grow to a fixed height (usually 3 to 4 feet), produce most of their fruit at once, and work well in containers or small gardens. Indeterminate varieties keep growing all season, produce fruit continuously until frost, and need staking or caging—they're the choice if you want tomatoes from July through September.

Next, match the variety to your climate. If you live where summers are short, choose early-maturing varieties like 'Early Girl' or 'Siberia' that fruit in 50 to 60 days. In longer-season areas, you can grow slower varieties like 'Brandywine' or 'Cherokee Purple' that take 70 to 85 days but have richer flavor. Check your seed packet or the nursery label for the days to maturity and compare it to the number of frost-free days in your area—you can find this by searching "[your city] frost date" online.

Key Takeaways

  • Determinate tomatoes grow to a fixed size and fruit all at once; indeterminate varieties grow all season and need staking.
  • Start seeds indoors 6 to 8 weeks before your last spring frost, or buy transplants from a nursery if you don't have grow lights.
  • Plant seedlings deeper than they grew in their pot—bury the stem up to the first true leaves to encourage a stronger root system.
  • Tomatoes need at least 6 to 8 hours of direct sun daily, consistent watering (about 1 to 2 inches per week), and support as they grow.
  • Prune suckers on indeterminate varieties and remove lower leaves once fruit sets to improve air flow and reduce disease.

Starting seeds indoors or buying transplants

If you have a sunny windowsill or grow lights, start seeds indoors 6 to 8 weeks before your last spring frost date. Fill a seed tray with seed-starting mix (not garden soil), plant seeds about a quarter-inch deep, keep the soil moist but not waterlogged, and maintain a temperature around 70°F. Seedlings will sprout in 5 to 10 days. Once they have their first true leaves (the second set to appear), thin them so each seedling has its own cell or small pot.

If you don't have grow lights or prefer not to start from seed, buy transplants from a garden center or nursery 2 to 3 weeks before your last frost. Look for stocky plants with dark green leaves and no flowers yet—flowering transplants often struggle after planting because they've already used energy on blooms instead of roots.

Harden off seedlings before planting them outside by setting them in a sheltered spot outdoors for a few hours each day, gradually increasing exposure over a week. This acclimates them to wind, direct sun, and temperature swings so they don't wilt when transplanted.

Planting in the garden or containers

Plant seedlings outdoors after your last spring frost, when soil has warmed to at least 60°F. Choose a spot with 6 to 8 hours of direct sun—less sun means slower growth and fewer fruits. Dig a hole deeper than the root ball and bury the stem up to the first set of true leaves; tomatoes will grow roots all along the buried stem, creating a stronger foundation. Space plants 24 to 36 inches apart for indeterminate varieties and 18 to 24 inches for determinate types.

For containers, use a pot at least 5 gallons for determinate varieties and 10 gallons for indeterminate ones. Fill it with potting mix (not garden soil), plant the seedling at the same depth as you would in the ground, and water thoroughly. Container plants dry out faster than garden soil, so you'll water more often—usually every 1 to 2 days in hot weather.

At planting time, install a cage or stake next to the plant so you don't damage roots later. Indeterminate varieties need sturdy cages or stakes at least 5 to 6 feet tall.

Watering and feeding through the season

Tomatoes need consistent moisture—about 1 to 2 inches of water per week from rain or irrigation. Water deeply at the soil level rather than overhead; wet leaves invite fungal diseases like early blight and late blight. The best time to water is early morning so any splash dries quickly. If you're in a hot or dry climate, mulch around the base with 2 to 3 inches of straw or shredded leaves to retain moisture and keep roots cool.

Feed plants every 2 to 3 weeks once they start flowering. Use a balanced fertilizer (like 10-10-10) or a tomato-specific formula that's higher in phosphorus and potassium to encourage fruiting rather than excessive leaf growth. Follow the package directions for the amount. If you mixed compost into the soil at planting, you may need less supplemental feeding.

Watch for signs of nutrient deficiency: yellowing lower leaves usually mean nitrogen is low, and blossom end rot (dark sunken spots on the bottom of fruit) signals calcium deficiency, often caused by irregular watering. Consistent watering prevents most of these problems.

Pruning and supporting indeterminate varieties

Suckers are shoots that grow in the angle between the main stem and branches. On indeterminate varieties, remove them by pinching them off by hand when they're small. This directs energy into fruit production rather than extra foliage. On determinate varieties, you can leave suckers alone since the plant naturally stops growing at a set height.

Once fruit begins to set, remove the lowest leaves on the plant—those within 12 inches of the ground. This improves air circulation, reduces soil splash onto leaves, and cuts down on fungal disease. Continue removing lower leaves as the plant grows, but never strip more than a third of the foliage at once.

Tie indeterminate plants to their stake or cage loosely with soft ties (old cloth strips work well) every 8 to 12 inches as they grow. The ties should support the stem without cutting into it.

Recognizing and managing common problems

Early blight appears as brown spots with concentric rings on lower leaves, usually in mid to late summer. Remove affected leaves and improve air flow by pruning. Late blight causes water-soaked spots on leaves and fruit and spreads quickly in cool, wet weather—if you see it, remove the entire plant to prevent spread to neighbors' gardens.

Blossom end rot shows as a dark, sunken spot on the bottom of the fruit and is caused by calcium deficiency linked to uneven watering. Water consistently and mulch to prevent it. Affected fruit can be cut away and the rest eaten, but prevention is easier than managing it.

Hornworms are large green caterpillars that can strip a plant quickly. Hand-pick them in the early morning or late evening, or spray with spinosad (an organic insecticide) if the infestation is heavy. Whiteflies and spider mites are less common but can appear in hot, dry weather—spray the undersides of leaves with water or insecticidal soap.

Harvesting and ripening fruit

Tomatoes can be picked at the breaker stage—when the first blush of color appears on the bottom—and ripened indoors on a windowsill. This is useful if frost is coming or if you want to protect ripe fruit from birds and insects. Fully ripe tomatoes picked warm from the sun have the best flavor, but either way, never refrigerate tomatoes until they're fully ripe; cold stops the ripening process and damages flavor.

Keep harvesting as fruit ripens to encourage the plant to keep producing. On indeterminate varieties, you can harvest until the first hard frost. In early fall, pinch off any new flowers so the plant puts energy into ripening existing fruit rather than starting new ones that won't mature before frost.

Frequently Asked Questions

Can I grow tomatoes in a pot on a patio?

Yes, as long as the pot is at least 5 gallons and gets 6 to 8 hours of direct sun. Use potting mix, not garden soil, and water more often because containers dry out faster. Determinate varieties work better in pots than indeterminate ones because they stay smaller.

Why are my tomato flowers dropping without setting fruit?

Flowers drop when temperatures swing too much (below 55°F at night or above 90°F during the day), when watering is inconsistent, or when nitrogen is too high. Keep soil evenly moist and avoid over-fertilizing with nitrogen. Early-season flowers often drop naturally; the plant usually sets fruit once temperatures stabilize.

How do I know when to pick a tomato?

Pick when the tomato is fully colored and yields slightly to gentle pressure. If frost is forecast, pick any tomato showing color and ripen it indoors. Tomatoes picked at the breaker stage (first hint of color) will ripen on a windowsill in 3 to 7 days.

Do I need to use a cage or stake?

Indeterminate varieties must have support or they'll sprawl and break under the weight of fruit. Determinate varieties can grow without support but produce cleaner fruit and are easier to harvest if caged. Staking takes less space than caging in a small garden.

What should I do with my tomato plants at the end of the season?

Pull plants once frost kills them or production slows in fall. Compost healthy plants, but throw diseased ones in the trash to avoid spreading disease next year. Don't plant tomatoes in the same spot the following year—rotate to a different bed to reduce soil-borne disease buildup.