Start with soil, sunlight, and the right variety for your space

Tomatoes need six to eight hours of direct sunlight daily, soil that drains well, and consistent water — not soggy, not dry. The three things that fail most tomato plants are too little light, soil that holds water, and irregular watering. Before you buy seeds or seedlings, check whether your garden spot gets real sun (not afternoon shade from a building or tree) and whether water pools there after rain.

Choose a variety based on your climate and what you want to eat. Determinate varieties (bush types) grow to a set size and produce most fruit at once — good for canning or sauce. Indeterminate varieties (vine types) grow taller, produce fruit all season, and need staking or caging. Cherry tomatoes are forgiving for beginners. Paste tomatoes like San Marzano are dense and good for sauce. Slicing tomatoes like Brandywine are large but need more care.

Key Takeaways

  • Tomatoes need six to eight hours of direct sun and soil that does not stay wet; check your garden spot before planting.
  • Start seeds indoors six to eight weeks before your last frost date, or buy seedlings from a nursery if you do not have grow lights.
  • Plant seedlings deeper than they were in their pot, bury part of the stem, and space them two to three feet apart.
  • Water at the soil level early in the morning, not on the leaves, and keep the soil consistently moist but not waterlogged.
  • Indeterminate varieties need stakes or cages for support; remove lower leaves as the plant grows to reduce disease.

Starting from seed indoors or buying seedlings

If you have a sunny windowsill or grow lights, start seeds indoors six to eight weeks before your last spring frost. Fill a seed tray with seed-starting mix (not garden soil), plant seeds a quarter inch deep, keep the soil moist, and maintain a temperature around 70°F. Seedlings will sprout in five to ten days. Once they have two true leaves (the second set that appears), move them to individual pots.

If you do not have lights or space, buy seedlings from a local nursery in spring. Look for plants that are stocky and green, not tall and spindly or already flowering. Seedlings in four-inch pots are easier to harden off (gradually expose to outdoor conditions) than larger ones. Avoid plants with yellowing leaves or roots coming out of the drainage holes.

Hardening off seedlings and planting outdoors

One to two weeks before planting outside, harden off your seedlings by setting them in a sheltered spot outdoors for a few hours, then gradually increasing time outside over seven to ten days. This prevents shock when they move from indoor warmth to outdoor wind and sun. Plant outdoors after your last frost date, when soil temperature is at least 60°F.

Dig a hole slightly deeper than the seedling's pot. Tomatoes can be planted deeper than they grew — bury the stem up to the lowest leaves, and roots will form along the buried stem, making a stronger plant. Space determinate varieties two feet apart and indeterminate varieties three feet apart. Water well after planting.

Watering and feeding through the season

Water at soil level in the early morning, not on the leaves. Wet leaves invite fungal disease. Tomatoes need about one to two inches of water per week, depending on heat and rainfall. The soil should feel moist two inches down, not soggy. Inconsistent watering — dry one week, flooded the next — causes problems like blossom end rot (dark spots on the fruit) and fruit cracking.

Feed every two to three weeks once the plant starts flowering. Use a balanced fertilizer (like 10-10-10) or one higher in phosphorus and potassium (the last two numbers) to encourage fruit rather than leaf growth. Avoid high-nitrogen fertilizer, which produces leaves but few tomatoes. Follow the package directions for amount.

Supporting indeterminate varieties and pruning

Indeterminate tomatoes grow tall and need support. Install stakes or cages early, when the plant is small — driving stakes through roots later damages them. Tie the main stem loosely to the stake with soft ties as it grows, leaving room for the stem to thicken.

As the plant grows, remove leaves from the bottom up to about one foot above the ground. This improves air circulation, reduces fungal disease, and directs energy to fruit rather than foliage. Pinch off suckers (shoots that grow between the main stem and branches) on indeterminate varieties to keep the plant manageable and focus energy on fewer, larger fruit. Determinate varieties need less pruning.

Recognizing and preventing common problems

Blossom end rot appears as a dark, sunken spot on the bottom of the fruit and is caused by calcium deficiency linked to irregular watering. Keep soil consistently moist and mulch around the plant to regulate moisture. Early blight shows as brown spots with concentric rings on lower leaves and spreads upward; remove affected leaves and improve air circulation. Late blight causes water-soaked spots on leaves and fruit and spreads quickly in cool, wet weather; remove infected plants entirely.

Hornworms are large green caterpillars that eat leaves and fruit; pick them off by hand or spray with spinosad if the infestation is heavy. Whiteflies cluster on leaf undersides and weaken the plant; spray with neem oil or insecticidal soap. Mulch around the base with two to three inches of straw or wood chips to keep soil temperature even, reduce disease splash from rain, and retain moisture.

Harvesting and ripening

Tomatoes can be picked when they show color — they will continue to ripen off the vine. Pick fruit as it matures to encourage the plant to produce more. In late summer, when frost is coming, pick all remaining fruit, even green ones. Green tomatoes will ripen indoors at room temperature in a paper bag with a ripe banana or apple (which releases ethylene gas that speeds ripening), or on a sunny windowsill.

Indeterminate varieties produce until frost kills the plant. Determinate varieties finish producing within a few weeks, so succession planting (starting new seeds every two weeks) extends your harvest if you want tomatoes all season.

Frequently Asked Questions

Can I grow tomatoes in a pot?

Yes. Use a pot at least five gallons for determinate varieties and ten gallons for indeterminate types. Fill with potting soil, not garden soil. Container tomatoes dry out faster, so check soil moisture daily and water more often. They still need six to eight hours of sun.

Why are my tomato flowers dropping without making fruit?

Flowers drop when temperatures drop below 55°F at night or above 90°F during the day, when the plant is stressed by inconsistent watering, or when nitrogen is too high. Keep soil evenly moist, avoid over-fertilizing, and wait for warmer weather. Fruit will set once conditions improve.

What is the difference between determinate and indeterminate tomatoes?

Determinate varieties grow to a fixed size, produce most fruit at once, and stop growing. Indeterminate varieties grow continuously, produce fruit all season until frost, and need staking. Choose determinate for canning or sauce; choose indeterminate for fresh eating over months.

Do I need to remove all the leaves from my tomato plant?

No. Remove only the lower leaves (up to one foot above ground) to improve air circulation and reduce disease. Keep upper leaves — they feed the plant through photosynthesis. Removing too many leaves weakens the plant and exposes fruit to sunscald.

When should I stop watering my tomato plants?

Keep watering until frost kills the plant or you harvest the last fruit. Stopping water early stresses the plant and reduces yield. In fall, as temperatures drop, water less frequently but do not let soil dry out completely.