Water tomato plants deeply and regularly, but let the soil dry slightly between waterings

Tomato plants need consistent moisture, but not soggy soil. Water at the base of the plant—not the leaves—early in the morning or late in the afternoon. Aim for about 1 to 2 inches of water per week, either from rain or from you. The exact amount depends on your climate, soil type, and how hot it is; sandy soil dries faster than clay, and plants in full sun need more water than those in partial shade.

Stick your finger 2 inches into the soil. If it feels dry, water. If it feels moist, wait another day or two. Inconsistent watering—long dry spells followed by heavy watering—causes problems like blossom-end rot (dark sunken spots on the fruit) and fruit cracking. A soaker hose or drip line keeps water at soil level and reduces disease, since wet leaves are more prone to fungal infections.

Key Takeaways

  • Water at the base of the plant in early morning or late afternoon, aiming for 1 to 2 inches per week depending on your climate and soil type.
  • Prune suckers (shoots that grow between the main stem and branches) on indeterminate varieties to direct energy into fruit, but leave them on determinate types.
  • Support plants with stakes, cages, or strings as they grow, and tie them loosely so stems have room to expand.
  • Pinch off the top of the plant 4 to 6 weeks before your first frost date to stop new flowers from forming and let existing fruit mature.
  • Watch for yellowing leaves, brown spots, or soft spots on fruit, and remove affected leaves or fruit to prevent disease spread.

Stake or cage your tomato plants early to prevent damage as they grow

Tomato stems are brittle and break easily under the weight of fruit and wind. Install support when you plant or within the first week, before the plant is tall enough to damage. A determinate tomato (a bush type that grows to a fixed height, usually 3 to 4 feet) works well in a cage. An indeterminate tomato (a vining type that keeps growing all season, sometimes 6 feet or taller) does better with a stake or string system.

For a stake, use a wooden or metal pole at least 5 to 6 feet tall. Drive it 12 inches into the ground next to the plant. As the plant grows, tie the main stem to the stake loosely with cloth strips or soft ties every 8 to 12 inches. Leave room for the stem to expand—a tight tie will cut into the plant as it thickens. For a string system, run twine from the top of a horizontal wire or beam down to the base of the plant, and gently wrap the stem around the string as it grows.

Prune suckers on indeterminate varieties to focus energy on fruit

A sucker is a shoot that grows in the angle between the main stem and a branch. On indeterminate plants, suckers steal energy from fruit production. Pinch them off by hand when they are small (2 to 4 inches long) or cut them with pruning shears. On determinate plants, leave the suckers alone—they produce fruit and removing them reduces your harvest.

Start pruning suckers when the plant is about 12 inches tall and keep doing it throughout the season. The goal is not to strip the plant bare; you want to keep the main stem and 1 or 2 main branches so the plant still has enough leaves to feed itself. Too much pruning stresses the plant and exposes fruit to sunscald (white or yellow patches where sun burns the skin directly).

Pinch off the top of the plant in late summer so fruit has time to ripen

About 4 to 6 weeks before your first expected frost date, pinch off the growing tip at the top of the plant. This stops the plant from making new flowers, which would not have time to mature into ripe fruit before cold weather arrives. Removing the tip redirects the plant's energy into ripening the fruit already on the vine.

If you do not know your first frost date, search online for "[your city] first frost date." It varies by region—in the northern United States it may be late August or early September, while in the South it might be October or November. Pinching too early wastes potential harvest; pinching too late leaves you with green fruit that never ripens.

Remove yellowing or spotted leaves to prevent disease from spreading

Tomato plants are prone to fungal diseases like early blight and septoria leaf spot, which show up as brown or yellow spots on leaves, often with a target-like ring pattern. These diseases spread from leaf to leaf and from plant to plant, especially in humid conditions or when leaves stay wet. Remove any leaf that shows spots or yellowing as soon as you see it. Pinch it off by hand or cut it with clean shears, and throw it in the trash—not the compost pile.

Also remove leaves that touch the ground or are shaded by other foliage. Better air circulation and less moisture on the leaves means fewer disease problems. If you notice soft, mushy spots on the fruit itself, remove that fruit right away. A diseased fruit will not ripen properly and can spread infection to healthy fruit nearby.

Fertilize every 2 to 3 weeks once the plant starts flowering

Tomato plants need nitrogen early in the season to build strong stems and leaves, but too much nitrogen late in the season produces lots of foliage and few flowers. Once the plant starts to flower, switch to a fertilizer lower in nitrogen and higher in phosphorus and potassium—these nutrients support flowering and fruit development. A balanced fertilizer like 5-10-10 or a tomato-specific formula works well.

Follow the label instructions for how much to use and how often. Most gardeners fertilize every 2 to 3 weeks. If your soil is rich in organic matter (you mixed in compost when planting), you may need less fertilizer. If you see pale leaves or slow growth, the plant may need feeding sooner. Fertilize at the base of the plant, not on the leaves, and water after explore so the nutrients reach the roots.

Harvest fruit when it reaches full color but is still slightly firm

Tomatoes ripen from the inside out. A fully ripe tomato is deeply colored (red, pink, yellow, or whatever color your variety is), soft to the touch but not mushy, and comes off the vine with a gentle twist. Pick fruit in the morning when it is cool. If you pick a tomato that is still slightly green or pale, it will continue to ripen on the counter at room temperature—you do not need to leave it on the vine.

Toward the end of the season, when frost is coming, pick all remaining fruit—even the green ones. Tomatoes ripen faster indoors than they do on a dying plant. Place them in a paper bag or cardboard box with a ripe banana or apple (these release ethylene gas, which speeds ripening) and store them at room temperature, out of direct sunlight. Check them daily and remove any that show soft spots or mold.

Frequently Asked Questions

Why are the bottoms of my tomatoes rotting?

Blossom-end rot is caused by a calcium deficiency, usually from inconsistent watering. The plant cannot move calcium to the fruit when the soil dries out. Water deeply and regularly, and mulch around the base to keep soil moisture even. Remove affected fruit and prevent it on future fruit by maintaining steady watering.

What should I do if my tomato leaves are turning yellow?

Yellowing leaves can mean too much water, too little water, nitrogen deficiency, or disease. Check the soil—if it is soggy, reduce watering. If it is dry, water more. If the yellowing starts at the bottom of the plant and moves up, it is likely normal aging or early blight; remove those leaves. If the whole plant is pale, fertilize with a balanced formula.

Can I grow tomatoes in a pot?

Yes. Use a pot at least 5 gallons for a determinate variety and 10 gallons or larger for an indeterminate. Fill it with potting soil (not garden soil), water regularly because pots dry out faster than ground, and fertilize every 2 weeks since nutrients wash out with watering. Pots need drainage holes and should sit in a spot with at least 6 to 8 hours of direct sun.

How do I know when to stop watering my tomato plants?

Stop regular watering about 2 weeks before you plan to harvest the last fruit. This concentrates sugars in the remaining tomatoes and makes them taste sweeter. The plant will wilt slightly during the day, which is normal. Water only if the plant looks severely stressed or if there is no rain for more than a week.