Start with soil, light, and water — the three things tomatoes need most
Tomato plants grow best in soil that drains well, gets at least six to eight hours of direct sunlight each day, and stays consistently moist but not waterlogged. The soil should be loose enough that water passes through it rather than pooling on top. If your garden soil is heavy clay, mix in compost or peat moss to improve drainage. Tomatoes also need warmth — they grow slowly below 60°F and stop growing altogether below 50°F, so wait until nighttime temperatures stay above 50°F before planting outdoors.
Water deeply and less often rather than a little bit every day. Shallow watering encourages roots to stay near the surface, where they dry out quickly. Water at the base of the plant, not the leaves, to reduce disease. Most tomato plants need about one to two inches of water per week, but this varies depending on rainfall, heat, and soil type. In hot weather or sandy soil, you may need to water more often.
Sunlight is non-negotiable. Tomatoes planted in partial shade produce fewer fruits and ripen more slowly. If your yard has limited sun, choose a spot that gets morning light — this also helps dry dew from the leaves and reduces fungal disease.
Key Takeaways
- Plant tomatoes in soil that drains well, in a spot with at least six to eight hours of direct sun, and wait until nighttime temperatures stay above 50°F.
- Water deeply at the base of the plant one to two times per week rather than daily, and adjust based on rainfall and heat.
- Support indeterminate varieties (which grow tall) with stakes or cages, and prune suckers to direct energy toward fruit rather than leaves.
- Harvest tomatoes when they reach full color but are still slightly firm, or pick them green and ripen them indoors if frost is coming.
- Watch for common pests like hornworms and aphids, and for diseases like early blight, which spreads from soil splash on wet leaves.
Choose between determinate and indeterminate varieties based on your space
Determinate tomatoes grow to a fixed height (usually three to four feet), produce most of their fruit at once, and stop growing. These are good for containers, small gardens, and canning because the harvest is concentrated. Indeterminate tomatoes grow continuously throughout the season, reaching six feet or taller, and produce fruit steadily until frost. They need staking or caging and more pruning, but they produce more total fruit over a longer period.
Common determinate varieties include Roma, San Marzano, and Mountain Magic. Common indeterminate varieties include Brandywine, Cherokee Purple, and Sungold. Check the seed packet or plant label to see which type you have — this determines how much space and support you need to provide.
Plant seedlings or seeds at the right depth and spacing
If you start from seed indoors, plant seeds about one-quarter inch deep in moist seed-starting mix six to eight weeks before your last spring frost. Keep the soil warm (around 70°F) and moist until seedlings emerge, which usually takes five to ten days. Once seedlings have their first true leaves (the second set to appear), move them to a sunny window or under grow lights.
When seedlings are four to six inches tall and have at least two sets of true leaves, they are ready to transplant outdoors or into larger pots. Space plants two to three feet apart for determinate varieties and three to four feet apart for indeterminate varieties. Bury the stem deeper than it was growing in the pot — tomatoes will develop roots along the buried stem, creating a stronger root system. You can bury the stem up to the first set of true leaves.
Support tall plants and prune to direct growth
Indeterminate tomatoes need support to keep fruit off the ground and improve air circulation. Use stakes (wooden or metal poles driven into the ground next to the plant) or cages (wire structures that surround the plant). Cages are easier for beginners but work best for determinate varieties; stakes require tying the plant as it grows but give you more control over the shape.
Pruning means removing suckers — the shoots that grow between the main stem and branches. Removing suckers directs the plant's energy toward producing fruit rather than extra leaves. On indeterminate varieties, pinch off suckers when they are small. On determinate varieties, light pruning is usually enough. Remove any leaves that touch the ground or show signs of disease, as these can spread fungal infections.
Fertilize every two to three weeks once flowers appear
Tomatoes are heavy feeders and need nutrients throughout the growing season. Before planting, work compost or a balanced fertilizer (such as 10-10-10) into the soil. Once the plant flowers, switch to a fertilizer higher in phosphorus and potassium (the second and third numbers on the package), such as 5-10-10, to encourage fruit production rather than leaf growth.
Fertilize every two to three weeks according to the package directions. Avoid over-fertilizing with nitrogen, which produces lots of leaves but few fruits. If leaves turn yellow, the plant may need more nitrogen; if growth slows and leaves look pale, it may need more phosphorus or potassium. Foliar feeding (spraying diluted fertilizer on the leaves) can provide a quick nutrient boost, though soil feeding is more reliable.
Watch for pests and diseases, especially in humid conditions
Tomato hornworms are large green caterpillars that eat leaves and fruit. Hand-pick them when you see them, or use Bacillus thuringiensis (Bt), a natural pesticide that kills caterpillars without harming other insects. Aphids are small soft-bodied insects that cluster on new growth; spray them off with water or use insecticidal soap.
Early blight is a fungal disease that causes brown spots with rings on lower leaves and spreads upward. It thrives in wet conditions and spreads through soil splash. Prevent it by watering at the base of the plant, removing lower leaves once the plant is established, and spacing plants so air circulates. If early blight appears, remove affected leaves and spray with a fungicide containing chlorothalonil or copper.
Blossom end rot appears as a dark, sunken spot on the bottom of the fruit and is caused by calcium deficiency, usually from inconsistent watering. Prevent it by watering deeply and regularly, and by mulching around the base of the plant to keep soil moisture steady.
Harvest when fruit is fully colored but still slightly firm
Tomatoes ripen from the inside out. Pick them when they reach full color for the variety (red, orange, yellow, or purple depending on the type) but are still slightly firm to the touch. Ripe tomatoes come off the vine with a gentle twist. Harvesting regularly encourages the plant to produce more fruit.
If frost is forecast and you have green tomatoes still on the vine, pick them and ripen them indoors. Place them in a cardboard box or paper bag with a ripe banana or apple, which releases ethylene gas and speeds ripening. They will ripen in a few days to a few weeks depending on how mature they were when picked. Tomatoes picked at the mature green stage (full size but still green) ripen better than those picked too early.
Frequently Asked Questions
Why are my tomato flowers dropping off without making fruit?
Flowers drop when temperatures are too hot (above 85°F at night), too cold (below 55°F at night), or when the plant is stressed by inconsistent watering or too much nitrogen fertilizer. may support the plant gets steady water, avoid over-fertilizing, and wait for temperatures to stabilize. The plant will produce new flowers once conditions improve.
Can I grow tomatoes in containers?
Yes. Use a pot at least five gallons for determinate varieties and ten gallons for indeterminate varieties, with drainage holes in the bottom. Fill it with potting soil (not garden soil, which compacts in containers). Container tomatoes dry out faster than in-ground plants, so check soil moisture daily and water when the top inch feels dry. Fertilize every two weeks because watering leaches nutrients from the soil.
What should I do if my tomato plant is growing tall and spindly?
Spindly growth means the plant is not getting enough light. Move it to a sunnier location or place it under grow lights positioned four to six inches above the plant. If the plant is already in the garden, thin nearby plants or remove competing vegetation to increase light exposure.
How do I know when to stop watering in fall?
Stop watering about two weeks before your first expected frost date. This slows growth and allows the plant to focus energy on ripening remaining fruit rather than producing new leaves. Pick all remaining fruit before the first frost, as frost kills the plant.