Start with the right location and timing for your tomatoes

Tomatoes need at least six to eight hours of direct sunlight daily — more is better. Before you plant, walk your yard at different times of day and note which spots stay sunny. Afternoon shade in very hot climates (above 90°F regularly) can actually help prevent sunscald on fruit, but morning sun is essential everywhere.

Timing depends on your local frost dates. Tomatoes are killed by frost, so you plant them after your last spring frost date has passed and the soil has warmed to at least 60°F — ideally 65°F or higher. You can start seeds indoors six to eight weeks before that date, or buy transplants from a nursery closer to planting time. Check your local extension office or search "[your city] frost date" to find the exact window for your area.

Key Takeaways

  • Tomatoes need six to eight hours of direct sun daily and soil warmed to at least 60°F before planting outdoors.
  • Space determinate (bush) varieties 24 to 36 inches apart and indeterminate (vining) varieties 36 to 48 inches apart to allow air circulation and prevent disease.
  • Prepare soil by mixing in compost or aged manure to improve drainage and add nutrients before you plant.
  • Plan for support structures — stakes, cages, or trellises — before planting, because installing them after damages roots.
  • Water deeply and consistently; tomatoes need about one to two inches per week from rain or irrigation combined.

Measure spacing based on the variety you choose

Determinate (bush) tomatoes grow to a fixed height, usually 3 to 4 feet, and produce most fruit at once. Space these 24 to 36 inches apart. Indeterminate (vining) tomatoes grow continuously throughout the season and can reach 6 feet or taller. Space these 36 to 48 inches apart. The seed packet or plant label will tell you which type you have.

Spacing matters because it allows air to move between plants, which reduces fungal diseases like early blight and late blight. Crowded plants stay wet longer after rain or watering, and wet leaves are where disease takes hold. If you are growing in containers, use pots at least 5 gallons for determinate varieties and 10 gallons for indeterminate ones.

Prepare soil before planting day

Tomatoes are heavy feeders and prefer soil rich in organic matter. Two to three weeks before planting, work compost, aged manure, or peat moss into the top 8 to 12 inches of soil. This improves drainage, adds nutrients, and helps the soil hold moisture without becoming waterlogged. If your soil is clay-heavy and drains poorly, adding compost is especially important.

You can also add a balanced fertilizer (something like 5-10-10 or 10-10-10) at planting time, following the package directions. Avoid high-nitrogen fertilizers, which push leaf growth at the expense of fruit. If you are planting in containers, use potting soil mixed with compost rather than garden soil, which compacts in pots.

Install support structures before you plant

Decide now whether you will use stakes, cages, or a trellis system. Installing supports after planting damages roots and stresses the plant. For indeterminate varieties, stakes or trellises are more effective than cages because the plants grow taller than most cages can handle. For determinate varieties, a sturdy cage often works well.

Wooden stakes should be at least 6 feet tall for indeterminate types and 4 feet for determinate ones. Metal cages designed for tomatoes are typically 5 to 6 feet tall. If you use a trellis, make sure it is sturdy enough to support the weight of fruit and vines — tomato plants become heavy as they mature.

Plan your watering system

Tomatoes need consistent moisture — about one to two inches per week from rain and irrigation combined. Inconsistent watering causes problems like blossom-end rot (a dark, sunken spot on the bottom of the fruit) and fruit cracking. Drip irrigation or soaker hoses deliver water directly to the soil and keep leaves dry, which reduces disease. If you hand-water, water at the base of the plant early in the morning.

Mulch around plants with 2 to 3 inches of straw or shredded leaves once the soil has warmed. Mulch keeps soil moisture steady, moderates temperature, and prevents soil from splashing onto lower leaves (where disease spores live). Leave a few inches of space between the mulch and the stem to prevent rot.

Account for sunlight patterns and air movement

Beyond the six to eight hours of direct sun, think about where wind moves through your garden. A little air movement is good for disease prevention, but strong wind can damage plants and dry soil too quickly. If your garden is in a windy spot, you may need to water more often or add a windbreak.

Also consider shade from nearby trees or structures. Tomatoes planted on the east side of a building get morning sun (which dries dew quickly) and afternoon shade in hot climates — often an ideal setup. Avoid planting where tomatoes grew last year or the year before, because soil-borne diseases can persist. Rotate tomatoes to a different bed every three years if possible.

Plan for succession planting if you want continuous harvest

If you want tomatoes throughout the season rather than one big harvest, plant new seedlings every two to three weeks until mid-summer. This staggers maturity so you have ripe fruit over a longer period. In hot climates, stop planting by mid-summer because plants set fruit poorly when nighttime temperatures stay above 75°F.

You can also plant both determinate and indeterminate varieties. Determinate types produce heavily for a few weeks (good for canning or sauce-making), while indeterminate types produce steadily until frost. Growing both gives you flexibility in how you use your harvest.

Frequently Asked Questions

Can I plant tomatoes in the same spot every year?

It is not recommended. Soil-borne diseases like fusarium and verticillium wilt persist in soil and infect tomatoes year after year. Rotate tomatoes to a different bed every three years if possible. If you must replant in the same spot, remove the top 6 inches of soil and replace it with fresh compost.

How deep should I plant tomato seedlings?

Plant seedlings deeper than they grew in their pot — bury the stem up to the first true leaves. Tomatoes will root along the buried stem, creating a stronger root system. This is one of the few times burying a plant deeper than it was growing is the right choice.

What if my garden gets only four hours of sun?

Tomatoes will grow with less sun, but they produce fewer fruit and ripen more slowly. Cherry tomatoes tolerate shade better than large slicing varieties. If your garden is shaded, choose a cherry or smaller variety and accept a smaller harvest.

Should I plant tomatoes in raised beds or in-ground?

Both work. Raised beds warm up faster in spring and drain better, which is helpful in wet climates. In-ground planting works fine if your soil drains reasonably well. The main advantage of raised beds is easier access and better control over soil quality.

How close can I plant tomatoes to other vegetables?

Keep tomatoes at least 3 feet away from brassicas (cabbage, broccoli) and fennel, which can inhibit tomato growth. Basil, carrots, and marigolds are good companions. Avoid planting near potatoes or peppers, which share the same diseases.