Start with seeds or seedlings, then move to soil and sunlight

Growing tomatoes begins with choosing between starting from seed indoors or buying seedlings from a garden center. Seeds take 6 to 8 weeks to become transplant-ready plants, while seedlings skip that step entirely. Either way, tomatoes need full sun (at least 6 to 8 hours daily), warm soil between 65 and 85 degrees Fahrenheit, and soil rich in organic matter. The plant will grow in a pot or in the ground, but the ground gives you more room for roots to spread and more stable moisture.

The timeline from planting to first harvest is typically 60 to 85 days, depending on the variety. Determinate varieties (bush types) mature faster and produce most fruit at once. Indeterminate varieties (vining types) grow taller, need staking or caging, and produce fruit throughout the season until frost kills the plant.

Key Takeaways

  • Tomatoes need at least 6 to 8 hours of direct sun daily and soil warmed to 65 degrees Fahrenheit or higher before you plant.
  • Space plants 24 to 36 inches apart so air can flow around leaves and reduce disease.
  • Water deeply at the soil level once or twice weekly rather than daily shallow watering, which encourages weak roots and fungal problems.
  • Pinch off the bottom leaves once the plant is established, and remove suckers (shoots between the main stem and branches) on indeterminate varieties to direct energy into fruit.
  • Most tomatoes are ready to pick when fully colored, but you can harvest them at the breaker stage (just starting to show color) and let them ripen indoors.

Prepare soil and choose a planting location

Tomatoes are heavy feeders and need soil with plenty of organic matter. Mix compost or aged manure into the top 8 to 10 inches of soil before planting. If you are using a pot, fill it with potting mix (not garden soil), which drains better and holds fewer soil-borne diseases. A 5-gallon pot is the minimum for a determinate variety; indeterminate types do better in 10-gallon pots or larger.

Choose a spot that gets sun from morning through afternoon. Morning sun dries dew from leaves, which helps prevent fungal diseases like early blight and powdery mildew. Avoid planting where tomatoes, peppers, or potatoes grew in the previous two years, since they share the same diseases and pests. If you must reuse the same spot, replace the top 6 inches of soil.

Plant seedlings at the right depth and spacing

Bury seedlings deeper than they were growing in their containers—up to the first true leaves. Tomato stems develop roots all along their length, so deeper planting creates a stronger root system. Space plants 24 to 36 inches apart (determinate varieties can be closer at 24 inches; indeterminate types need 36 inches). Crowding traps moisture and blocks air flow, which invites disease.

If you are starting from seed indoors, sow seeds 6 to 8 weeks before your last spring frost date. Use seed-starting mix in a shallow tray, keep the soil moist but not waterlogged, and provide 14 to 16 hours of light daily under grow lights or on a sunny windowsill. Once seedlings develop their first true leaves (the second set to appear), thin them so each has its own cell or pot. Harden off seedlings by gradually exposing them to outdoor conditions over 7 to 10 days before transplanting.

Water deeply and consistently

Tomatoes need 1 to 2 inches of water per week, delivered in one or two deep soakings rather than daily sprinkles. Water at soil level in the early morning, directing water away from leaves. Wet foliage invites fungal diseases, and morning watering gives leaves time to dry before nightfall.

Inconsistent watering causes problems: too little stresses the plant and invites spider mites; too much causes root rot and splits fruit. If the soil is dry 2 inches down, water deeply until water drains from the bottom of the pot or runs off the soil surface. In hot weather, you may need to water every other day. Mulch around the base with 2 to 3 inches of straw or shredded leaves to keep soil temperature steady and reduce water loss.

Support indeterminate varieties and prune for air flow

Indeterminate tomatoes grow as tall as 6 to 10 feet and must be staked or caged to keep fruit off the ground. Install a cage or stake at planting time so you do not damage roots later. Determinate varieties stay compact and usually need no support, though a small cage can prevent branches from breaking under fruit weight.

Once plants are 12 inches tall, remove the bottom 4 to 6 leaves to improve air circulation and reduce soil splash (which spreads disease). As the plant grows, continue removing lower leaves. On indeterminate varieties, pinch off suckers—the shoots that grow between the main stem and branches—to direct energy into fruit rather than extra foliage. Leave the main stem and the branches that bear flowers intact. Stop pruning 4 to 6 weeks before your first expected frost so the plant can focus on ripening existing fruit rather than producing new growth.

Feed the plant as it grows

Tomatoes need nitrogen early to build leaves, then phosphorus and potassium to support flowering and fruiting. If you mixed compost into the soil at planting, that provides a slow release of nutrients for the first month. After that, feed every 2 to 3 weeks with a balanced fertilizer (such as 10-10-10) or a tomato-specific formula (higher in phosphorus and potassium, lower in nitrogen).

Follow the package directions for your fertilizer type—liquid fertilizers work faster but need more frequent process, while granular or slow-release fertilizers need fewer feedings. Avoid over-feeding with nitrogen, which produces leafy plants with few flowers and fruit. If leaves turn yellow, the plant may need more nitrogen; if flowering slows, it may need more phosphorus and potassium.

Harvest ripe fruit and handle common problems

Pick tomatoes when they are fully colored and yield slightly to gentle pressure. Ripe tomatoes come off the vine with a light twist. If frost is forecast before fruit ripens, pick all tomatoes at the breaker stage (when they show their first blush of color) and ripen them indoors at room temperature on a windowsill or countertop. They will not ripen in the refrigerator.

Common problems include blossom end rot (dark sunken spots on the bottom of fruit), caused by inconsistent watering and low calcium—prevent it by watering steadily and adding crushed eggshells or gypsum to the soil. Early blight (brown spots with concentric rings on lower leaves) spreads in wet conditions—remove affected leaves and improve air flow. Hornworms (large green caterpillars) can be picked off by hand or controlled with Bacillus thuringiensis (Bt), a natural bacterial spray. Whiteflies and spider mites appear in hot, dry conditions—spray with insecticidal soap or neem oil, following label directions.

Frequently Asked Questions

Can I grow tomatoes in a pot on a patio or balcony?

Yes, as long as the pot gets 6 to 8 hours of direct sun daily. Use a pot at least 5 gallons for determinate varieties and 10 gallons for indeterminate types. Fill it with potting mix, not garden soil, and water more often because pots dry out faster than ground soil. Determinate varieties are easier for containers because they stay compact.

What is the difference between determinate and indeterminate tomatoes?

Determinate varieties are bush-type plants that grow 3 to 4 feet tall, produce most fruit at once, and stop growing at a set height. Indeterminate varieties are vining plants that grow 6 to 10 feet tall, produce fruit continuously until frost, and need staking or caging. Determinate types are better for canning (all fruit ripens together); indeterminate types are better for fresh eating over a long season.

Why are my tomato flowers falling off without making fruit?

Flowers drop when temperatures are below 55 degrees Fahrenheit at night or above 90 degrees Fahrenheit during the day, when the plant is stressed by drought or overwatering, or when nitrogen is too high. may support consistent watering, avoid over-feeding with nitrogen, and wait for temperatures to stabilize. Flowers will return once conditions improve.

Can I save seeds from my tomatoes for next year?

Yes, but only from heirloom and open-pollinated varieties. Hybrid tomatoes (marked F1 on the seed packet) do not produce seeds that grow into plants like the parent. Scoop seeds and gel into a jar, add a little water, let them ferment for 2 to 3 days, rinse thoroughly, and dry on a paper towel for 2 to 3 weeks before storing in a cool, dry place.

When should I stop watering tomatoes in fall?

Reduce watering 4 to 6 weeks before your first expected frost to slow growth and direct energy into ripening existing fruit. Continue watering enough to keep the soil from drying out completely, but do not encourage new flowers or leaves. Once frost kills the plant, pull it out and compost it (unless it had disease, in which case discard it).