Plant tomatoes after the last frost date in your area, spacing them 24 to 36 inches apart in full sun

Tomato plants need warm soil and air to thrive — planting them too early kills them. Check your local frost date (your county extension office or a quick search for "[your city] last frost date" will tell you), then wait until soil temperature reaches at least 60°F, ideally 65°F or warmer. Tomatoes planted into cold soil sit dormant and rot before they grow.

Choose a spot that gets at least 6 to 8 hours of direct sunlight daily. More sun means more fruit and better flavor. Space plants 24 to 36 inches apart — closer spacing for determinate (bush) varieties, wider for indeterminate (vining) types. Crowded plants trap moisture and invite disease.

Dig a hole slightly deeper than the root ball and wider. Tomato plants can be planted deeper than they were growing in the pot — bury the stem up to the first true leaves, and roots will form along the buried stem, creating a stronger plant. Fill the hole with soil, water thoroughly, and add a 2 to 3-inch layer of mulch around the base, keeping it 2 inches away from the stem.

Key Takeaways

  • Plant tomatoes only after your area's last frost date and when soil temperature is at least 60°F, or they will rot in cold ground.
  • Space plants 24 to 36 inches apart in a location with 6 to 8 hours of direct sun daily.
  • Bury the stem deeper than the pot depth so roots form along the buried portion and create a stronger plant.
  • Water when ready after planting and add 2 to 3 inches of mulch around the base to retain moisture and regulate soil temperature.

Prepare the soil before planting

Tomatoes are heavy feeders and need rich, well-draining soil. Work compost or aged manure into the top 8 to 10 inches of soil before planting. If your soil is clay-heavy and drains poorly, mix in compost to improve structure — tomatoes in waterlogged soil develop root rot and fungal disease.

A soil test from your county extension office tells you what nutrients are present and what you need to add. If you cannot test, mix in a balanced fertilizer (something like 5-10-10 or 10-10-10) at planting time according to package directions. Avoid high-nitrogen fertilizers, which produce leafy plants with few tomatoes.

Support and stake your plants at planting time

Install stakes, cages, or trellises at planting time, not later. Driving a stake through roots after the plant is established damages them. Determinate varieties (bush types that grow to a set size) need a cage or short stake. Indeterminate varieties (vining types that grow all season) need a tall stake, string trellis, or sturdy cage at least 5 to 6 feet tall.

Push stakes 12 inches into the ground so they do not topple in wind. Tie the plant loosely to the support with soft material — old cloth strips, garden twine, or commercial plant ties work well. Tight ties cut into the stem as it thickens.

Water deeply and consistently after planting

Water when ready after planting, soaking the soil to settle it around the roots. For the first week, water every 2 to 3 days to keep soil consistently moist but not waterlogged. After that, water deeply once or twice a week depending on heat and rainfall — tomatoes need about 1 to 2 inches of water per week.

Water at the soil level, not on the leaves. Wet foliage invites fungal disease like early blight and powdery mildew. Drip irrigation or soaker hoses deliver water directly to the root zone and are more efficient than overhead watering. If you use a sprinkler, water early in the morning so leaves dry quickly.

Plant tomatoes in containers if you lack garden space

Container tomatoes work well on patios, balconies, or small yards. Use a pot at least 5 gallons for determinate varieties and 10 gallons or larger for indeterminate types. Fill with potting soil (not garden soil, which compacts in containers), and follow the same planting depth rule — bury the stem deeper than the pot depth.

Container plants dry out faster than in-ground plants, so check soil moisture daily during hot weather. Water when the top inch of soil feels dry. Containers also need more frequent feeding — mix a balanced fertilizer into the water every 2 to 3 weeks, or use a slow-release fertilizer mixed into the potting soil at planting time.

Harden off seedlings before moving them outdoors

If you started tomatoes from seed indoors, they need gradual exposure to outdoor conditions before planting. This process, called hardening off, prevents shock and sunburn. About 7 to 10 days before your planting date, place seedlings outdoors in a sheltered, shaded spot for 1 to 2 hours. Each day, increase their time outside and gradually move them into more direct sun.

By planting day, seedlings should spend the full day and night outdoors. This toughens the stems and leaves so they handle wind and sun without wilting. Seedlings that go straight from an indoor grow light to full sun often wilt, stop growing, or die.

Frequently Asked Questions

Can I plant tomatoes in the same spot every year?

No — tomatoes are prone to soil-borne diseases like fusarium and verticillium wilt that build up in the soil. Rotate tomatoes to a different bed every 3 to 4 years. If you must plant in the same spot, remove the top 6 inches of soil and replace it with fresh compost.

What is the difference between determinate and indeterminate tomatoes?

Determinate varieties grow to a fixed size (usually 3 to 4 feet), produce most fruit at once, and stop growing. Indeterminate varieties grow all season, reaching 6 feet or taller, and produce fruit continuously until frost. Determinate types suit canning; indeterminate types suit fresh eating over a long season.

Should I remove the bottom leaves when I plant?

Remove leaves that would be buried in soil, since they rot and invite disease. Leave all leaves above soil level — they feed the plant. As the plant grows, remove lower leaves once the plant is established to improve air circulation and reduce fungal disease.

How deep should the planting hole be?

Dig a hole as deep as the root ball is tall, then plant so the stem is buried up to the first true leaves (the leaves above the seed leaves). Roots will form along the buried stem. This creates a stronger root system than planting at the same depth as the pot.