Plant tomatoes in spring after the last frost, in a sunny spot with well-draining soil
Tomatoes need warmth and light to grow, so timing and location matter most. Plant seedlings (small plants you buy or start indoors) outdoors only after nighttime temperatures stay above 50°F—usually late April through May depending on where you live. Choose a spot that gets at least six to eight hours of direct sun each day. If you have heavy clay soil that stays wet, mix in compost or aged manure to help water drain away from the roots.
You can start from seed indoors six to eight weeks before your last frost date, or buy seedlings from a garden center a few weeks before planting time. Starting from seed takes longer but costs less. Buying seedlings is faster and works well for first-time growers.
Key Takeaways
- Plant tomato seedlings outdoors only after nighttime temperatures stay above 50°F, which usually happens in late spring.
- Choose a location with six to eight hours of direct sun and soil that drains well—add compost if your soil is heavy clay.
- Dig a hole deep enough to bury the stem up to the first true leaves, which helps the plant develop a stronger root system.
- Water deeply at the soil level once or twice a week rather than daily, and stake or cage the plant early to support its weight as it grows.
- Pinch off the bottom leaves once the plant is established to reduce disease and improve air circulation around the stem.
Prepare your soil before planting day
Test your soil texture by squeezing a handful when it is moist. If it clumps into a tight ball, it is too heavy with clay and needs amendment. If it falls apart when ready, it is sandy and will dry out too fast. Tomatoes do best in soil that holds moisture but does not stay soggy—what gardeners call "crumbly" soil.
Mix in two to three inches of compost, aged manure, or peat moss into the top six to eight inches of soil where you will plant. This improves drainage in clay soil and helps sandy soil hold water. Work the amendment in with a garden fork or spade a few days before planting if you can, so the soil has time to settle.
Dig the hole and plant the seedling correctly
Dig a hole slightly wider than the seedling's root ball and deep enough that you can bury the stem up to the first set of true leaves (the leaves that look like tomato leaves, not the smooth oval seed leaves). Tomatoes are unusual—they can grow roots all along the buried stem, which creates a stronger plant. Remove the lower leaves before planting so no foliage sits below the soil surface, where it can rot.
Set the seedling in the hole, backfill with soil, and press gently so the soil makes contact with the roots. Water when ready and thoroughly until water drains from the bottom of the hole. Space plants two to three feet apart so air can move between them as they grow.
Install support early and water consistently
Push a stake, cage, or trellis into the soil right after planting, before the roots spread. Waiting until the plant is large risks damaging roots and makes the plant harder to support. Determinate varieties (bush types that stay compact) need a cage. Indeterminate varieties (vining types that grow tall) do better with a stake or string trellis.
Water at the soil level once or twice a week, giving the plant one to two inches of water per week depending on heat and rainfall. Water in the morning so foliage dries quickly and reduces disease risk. Avoid wetting the leaves—water that sits on foliage encourages fungal problems like early blight and powdery mildew. Use a soaker hose or drip line if you have one, or water slowly at the base with a regular hose.
Prune lower leaves and monitor for common problems
Once the plant is three to four weeks old and growing well, pinch off the bottom six to eight inches of leaves. This improves air circulation, reduces soil splash onto foliage (which spreads disease), and directs the plant's energy upward. Remove any leaves that touch the ground as the plant grows.
Watch for yellowing leaves, brown spots, or wilting. Yellow leaves at the bottom are normal as the plant matures, but yellow leaves higher up can signal nitrogen hunger—side-dress with compost or a balanced fertilizer. Brown spots that look like concentric rings are early blight, a fungal disease; remove the affected leaves and improve air flow. Wilting despite wet soil can mean root rot from overwatering or poor drainage.
Feed the plant every two to three weeks
Tomatoes are heavy feeders and benefit from regular fertilizing once they start flowering. Use a balanced fertilizer (equal nitrogen, phosphorus, and potassium) or a tomato-specific formula every two to three weeks. Follow the package directions for amount—more is not better and can burn roots or create leafy plants with few flowers.
Alternatively, side-dress with compost every three weeks by spreading a one-inch layer around the base, keeping it a few inches away from the stem. This feeds the plant slowly as the compost breaks down and improves soil structure over time.
Harvest when fruit is fully colored but still slightly firm
Tomatoes ripen from the inside out, so color is the best guide. Pick fruit when it is fully colored but still has a slight give when you squeeze gently—not rock hard, not mushy. Ripe tomatoes come off the vine with a gentle twist. If frost threatens before fruit ripens, pick all tomatoes at the mature green stage (full size, pale green) and ripen them indoors on a windowsill or in a paper bag.
Harvest regularly to encourage the plant to keep flowering and setting new fruit. A single plant can produce 10 to 20 pounds of fruit over the season depending on variety and growing conditions.
Frequently Asked Questions
Can I plant tomatoes in a pot or container?
Yes. Use a pot at least 18 inches deep and wide with drainage holes. Fill it with potting soil (not garden soil), water regularly because containers dry out faster, and place it where it gets six to eight hours of sun. Container tomatoes need feeding every two weeks because water drains nutrients away.
What is the difference between determinate and indeterminate tomatoes?
Determinate varieties grow to a fixed size, flower all at once, and produce fruit over a short window—good for canning. Indeterminate varieties grow tall all season, flower and fruit continuously, and produce until frost. Indeterminate plants need taller stakes or trellises and more pruning.
Why are my tomato flowers dropping without making fruit?
Flowers drop when nighttime temperatures drop below 55°F or rise above 75°F, when the plant is stressed by drought or overwatering, or when nitrogen is too high. Water consistently, avoid overfeeding, and wait for stable warm weather. Fruit will set once conditions improve.
How do I know if my seedlings are ready to plant outside?
Seedlings are ready when they are four to six inches tall, have at least two sets of true leaves, and the soil temperature stays above 50°F at night. Harden them off first by placing them outside in a sheltered spot for a few hours each day, gradually increasing time over one week, so they adjust to wind and sun.
Can I save seeds from my tomatoes to plant next year?
Yes, but only from heirloom or open-pollinated varieties. Hybrid tomatoes produce seeds that do not grow true to type. Scoop seeds and gel into a jar, add water, let them ferment for two to three days, rinse, dry on a plate for two weeks, and store in a cool, dry place.