Start tomatoes indoors 6 to 8 weeks before your last spring frost, or buy seedlings from a garden center

You can grow tomatoes from seed indoors under lights, or skip that step and buy small plants ready to transplant. Starting from seed costs less and gives you more varieties to choose from, but takes time and equipment. Buying seedlings is faster and works just as well if you only want a few plants.

If you start from seed, fill a seed tray or small pots with seed-starting mix (not garden soil—it compacts too much). Plant seeds about a quarter-inch deep, keep the soil moist but not waterlogged, and place the tray in a warm spot—70 to 75 degrees Fahrenheit is ideal. Seeds sprout in 5 to 10 days. Once they sprout, move them under grow lights or a sunny south-facing window so they stay stocky and don't stretch toward the light.

Whether you start from seed or buy seedlings, harden them off before planting outside. This means setting them outside in a sheltered spot for a few hours each day, gradually increasing the time over a week. This toughens the plants so they don't wilt when they hit outdoor conditions.

Key Takeaways

  • Plant tomato seeds indoors 6 to 8 weeks before your last frost date, or buy seedlings and skip the indoor step entirely.
  • Tomatoes need at least 6 to 8 hours of direct sunlight daily and soil that drains well but stays consistently moist.
  • Bury the stem deep when you transplant—tomatoes will root along the buried stem and develop a stronger plant.
  • Pinch off suckers (shoots that grow between the main stem and branches) on indeterminate varieties to direct energy into fruit instead of leaves.
  • Harvest tomatoes when they reach full color; they continue to ripen off the vine if picked at the breaker stage (when the first blush of color appears).

Choose a location with 6 to 8 hours of direct sun and prepare the soil

Tomatoes are sun-hungry plants. They need at least 6 to 8 hours of direct sunlight each day to produce sweet fruit and resist disease. A south or west-facing spot is ideal. If your garden gets less sun, choose early-maturing varieties, which set fruit faster in shorter seasons.

Tomato soil should drain well but hold moisture. Mix compost or aged manure into the top 8 to 10 inches of garden soil before planting. If you are growing in containers, use a potting mix, not garden soil. A 5-gallon bucket works for one plant; larger containers (10 gallons or more) give roots more room and reduce how often you need to water.

Test your soil pH if you can—tomatoes prefer slightly acidic soil between 6.0 and 6.8. If your soil is very acidic or alkaline, amend it a few weeks before planting so it has time to balance.

Transplant seedlings after the last frost date, burying the stem deep

Wait until nighttime temperatures stay above 50 degrees Fahrenheit and all danger of frost has passed. Planting too early into cold soil shocks the plant and slows growth. Check your local frost date online—it varies by region.

Dig a hole slightly deeper than the seedling's root ball. Tomatoes have a special ability: they will root along any buried stem. So pinch off the lower leaves and bury the stem up to the first remaining leaves. This creates a stronger root system. Space plants 24 to 36 inches apart so air can circulate and reduce disease.

Water thoroughly after planting. The soil should feel moist 2 to 3 inches down, but not soggy. If the seedling wilts in the afternoon, shade it with a cloth or newspaper for a few days while it adjusts.

Water consistently and support the plant as it grows

Tomatoes need steady moisture—about 1 to 2 inches of water per week, depending on heat and rainfall. Water at the base of the plant in the morning, not on the leaves. Wet foliage invites fungal diseases like early blight and powdery mildew. Let the top inch of soil dry out between waterings, but never let the plant wilt.

As the plant grows, it will need support. Determinate varieties (bush types) stay compact and need a short cage or stake. Indeterminate varieties (vining types) grow tall all season and need a tall cage, stake, or string trellis. Install support early, when the plant is small—waiting until it is large risks damaging roots and stems.

Mulch around the base with 2 to 3 inches of straw or shredded leaves. Mulch keeps soil temperature steady, reduces watering needs, and prevents soil from splashing onto leaves during rain.

Fertilize every 2 to 3 weeks once flowers appear

Tomatoes are heavy feeders. Before planting, mix a balanced fertilizer (like 10-10-10) or compost into the soil. Once the plant flowers, switch to a fertilizer higher in phosphorus and potassium—these nutrients support fruit development. A 5-10-10 formula or tomato-specific fertilizer works well.

Feed every 2 to 3 weeks according to the package directions. Liquid fertilizers work faster; granular fertilizers release slowly over time. Avoid over-fertilizing with nitrogen, which produces lots of leaves but few tomatoes. If you added plenty of compost at planting, you may need less fertilizer overall.

Stop fertilizing about 4 weeks before your first expected frost. Late fertilizing pushes new growth that won't have time to mature.

Prune suckers on indeterminate varieties to focus energy on fruit

Indeterminate tomatoes (the tall, vining kinds) grow suckers—shoots that sprout between the main stem and the branches. These suckers will grow into full branches if left alone, creating a bushy plant with many leaves but fewer, smaller tomatoes. Determinate varieties (bush types) don't need this pruning.

Pinch off suckers when they are small, about 2 to 4 inches long. Pinch them between your thumb and finger, or use clean scissors. Leave the main stem and the main branches intact. This redirects the plant's energy into producing larger fruit instead of more foliage.

You can also remove the lowest leaves once the plant is established and flowering. This improves air circulation around the base and reduces disease pressure. Never strip more than a third of the leaves at once.

Watch for common pests and diseases, and harvest when ripe

Tomatoes attract hornworms (large green caterpillars), aphids, and spider mites. Check the undersides of leaves weekly. Hand-pick hornworms or spray with insecticidal soap if infestations are heavy. Diseases like early blight (brown spots with rings) and powdery mildew (white coating on leaves) spread in humid conditions. Remove affected leaves, improve air circulation, and water at the base only.

Harvest tomatoes when they are fully colored but still slightly firm. They continue to ripen after picking. If frost threatens before tomatoes ripen, pick them at the breaker stage (when the first blush of color appears) and ripen them indoors on a windowsill. Store ripe tomatoes at room temperature, not in the refrigerator—cold breaks down flavor and texture.

A healthy plant produces fruit for 6 to 8 weeks or until frost kills it. In warm climates, plants may produce into fall.

Frequently Asked Questions

Why are my tomato flowers dropping without setting fruit?

Flowers drop when temperatures are too hot (above 90 degrees at night), too cold (below 55 degrees), or when the plant is stressed by inconsistent watering or too much nitrogen. Keep soil moisture steady, provide afternoon shade in extreme heat, and avoid over-fertilizing. Fruit set usually resumes when conditions improve.

Can I grow tomatoes in a pot on a patio?

Yes. Use a pot at least 5 gallons for determinate varieties and 10 gallons or larger for indeterminate types. Fill it with potting mix, not garden soil. Containers dry out faster than garden beds, so check soil moisture daily and water when the top inch feels dry. Feed every 2 weeks because watering leaches nutrients from the pot.

What is the difference between determinate and indeterminate tomatoes?

Determinate varieties grow to a fixed height (usually 3 to 4 feet), flower all at once, and produce most fruit in a short window. They are good for canning. Indeterminate varieties grow tall all season, flower continuously, and produce fruit until frost. They need taller support and pruning but give you tomatoes over a longer period.

How do I know when a tomato is ripe enough to pick?

Pick tomatoes when they are fully colored for the variety—red, pink, yellow, or whatever color they should be. They should yield slightly to gentle pressure but not be soft. Tomatoes picked at the breaker stage (first hint of color) will ripen indoors in 3 to 5 days at room temperature.

Should I remove leaves from my tomato plant?

Remove only the lowest leaves once the plant is flowering and established, and only if they show disease or if foliage is so dense that air cannot circulate. Never strip more than a third of the leaves at once. Leaves feed the plant through photosynthesis, so removing too many slows growth and fruit production.