Water deeply and consistently, not daily
Tomato plants need steady moisture, but overwatering kills them faster than drought does. The goal is to keep the soil moist 2 to 3 inches down—not soggy, not dust-dry. Push your finger into the soil near the base of the plant; if it feels wet, wait another day or two before watering.
Water at the soil level, not on the leaves. Wet foliage invites fungal diseases like early blight and septoria leaf spot, which spread fast in warm, humid air. Water in the early morning so any splash dries quickly. Most plants need deep watering once or twice a week depending on heat and rainfall, not a little sprinkle every day.
In very hot weather (above 85°F), you may water more often, but the principle stays the same: soak the soil thoroughly, then let it dry slightly before the next watering. Container plants dry out faster than garden soil and need checking more often.
Key Takeaways
- Water at soil level in the early morning, aiming for moist (not wet) soil 2 to 3 inches deep, and let it dry slightly between waterings.
- Prune suckers—the shoots that grow between the main stem and branches—to direct energy into fruit rather than foliage.
- Support the plant with a cage or stake early, before it gets heavy, to prevent broken branches and disease from soil contact.
- Feed every two to three weeks with a balanced fertilizer once flowers appear, or use a slow-release fertilizer at planting time.
- Remove the lowest leaves once the plant is established to reduce fungal disease pressure from soil splash.
Prune suckers to focus growth on fruit
A sucker is a shoot that grows in the angle between the main stem and a branch. Left alone, it becomes a full branch that produces leaves but steals energy from fruit development. Pinching off suckers when they are small (1 to 2 inches long) is the easiest way to manage the plant's shape and boost yield.
Determinate varieties (bush types that grow to a fixed size and fruit all at once) need little or no pruning. Indeterminate varieties (vining types that grow all season) benefit from regular sucker removal. Pinch them off with your fingers or a clean knife—no special tool needed. Do this every week or two during the growing season.
You can also remove the lowest 6 to 12 inches of leaves once the plant is 12 to 18 inches tall. This improves air flow, reduces fungal spores splashing up from soil, and makes harvesting easier. Always remove leaves during the day so the wounds dry quickly.
Support the plant before it gets heavy
A mature tomato plant loaded with fruit is heavy and fragile. Install a cage or stake at planting time, before the roots spread and before the plant is tall. Waiting until the plant flops over means you risk breaking branches and damaging roots when you try to prop it up.
A cage is a wire frame that surrounds the plant; it works well for determinate varieties and smaller indeterminate types. A stake (a 5- to 6-foot wooden or metal post) works better for tall indeterminate varieties. Tie the main stem loosely to the stake with soft twine or cloth strips, checking the tie every few weeks as the stem thickens.
Avoid tying too tightly—the stem needs room to grow. Tie in a figure-eight pattern (one loop around the stake, one around the stem) so the stake does not rub the plant. Check ties after heavy rain or wind to make sure they have not cut into the stem.
Feed the plant once flowers appear
Tomatoes are heavy feeders. At planting time, work compost or aged manure into the soil. Once the plant flowers, it needs regular feeding to support fruit development. A balanced fertilizer (equal parts nitrogen, phosphorus, and potassium—look for something like 10-10-10 on the label) works well.
Feed every two to three weeks with a liquid fertilizer diluted to package strength, or use a slow-release granular fertilizer at planting time and follow the label for timing. Avoid high-nitrogen fertilizers (the first number much larger than the others), which push leafy growth at the expense of fruit.
If leaves turn pale yellow, the plant may need nitrogen. If flowers drop without setting fruit, it may be too hot, too dry, or lacking phosphorus. Consistent watering and feeding usually prevent these problems. Stop feeding in late summer so the plant directs energy into ripening fruit rather than new growth.
Watch for common pests and diseases
The most common tomato pests are hornworms (large green caterpillars that eat leaves), spider mites (tiny pests that cause yellowing and webbing), and whiteflies (small white insects on leaf undersides). Hornworms are straightforward to spot and remove by hand. For spider mites and whiteflies, spray the undersides of leaves with water to dislodge them, or use insecticidal soap if the problem is severe.
Fungal diseases—early blight, septoria leaf spot, and powdery mildew—spread in warm, humid air and wet foliage. Prevent them by watering at soil level, removing lower leaves, spacing plants for air flow, and removing infected leaves as soon as you see them. If disease is widespread, a fungicide labeled for tomatoes may help, but prevention is easier than cure.
Blossom end rot (dark, sunken spots on the bottom of fruit) is not a disease but a calcium deficiency caused by inconsistent watering. Keep soil moisture steady and mulch around the base to regulate soil temperature and moisture.
Harvest fruit at the right stage
Tomatoes ripen best at room temperature after they are picked, so you do not have to wait for them to turn fully red on the vine. Pick them when they show color (called the "breaker stage"—when the first blush of color appears) and let them finish ripening indoors. This also protects fruit from birds and pests.
Twist the fruit gently or use a knife to cut the stem. Handle ripe tomatoes carefully—they bruise easily. Store them at room temperature (around 70°F) away from direct sun. Do not refrigerate unless they are fully ripe; cold breaks down flavor and texture.
As fall approaches and nights cool, pick all remaining fruit—even green ones. Tomatoes stop ripening once nighttime temperatures drop below 50°F. Green tomatoes can ripen indoors in a paper bag or on a windowsill over a few weeks.
Mulch to regulate soil moisture and temperature
A 2- to 3-inch layer of mulch (straw, wood chips, or shredded leaves) around the base of the plant keeps soil moisture steady, prevents soil from splashing onto leaves, and keeps roots cooler in hot weather. Leave a few inches of space around the stem so air can circulate and the stem does not rot.
Mulch also suppresses weeds, which compete with the tomato plant for water and nutrients. As the mulch breaks down over the season, it adds organic matter to the soil, improving its structure and water-holding capacity.
Avoid piling mulch against the stem—this traps moisture and invites rot and pests. Refresh the mulch layer mid-season if it has broken down significantly.
Frequently Asked Questions
How often should I water tomato plants?
Most tomato plants need deep watering once or twice a week, depending on heat, rainfall, and soil type. Check the soil 2 to 3 inches down; if it feels dry, water deeply. In very hot weather, you may water more often. Container plants dry out faster and need checking every day or two.
Can I grow tomatoes in pots?
Yes. Use a pot at least 5 gallons for determinate varieties and 10 gallons for indeterminate types. Fill it with potting soil (not garden soil), water more often than in-ground plants, and feed every two weeks once flowers appear. Container plants dry out faster and need more frequent feeding because water drains away nutrients.
What does it mean if flowers fall off without making fruit?
Flower drop usually happens when temperatures are too hot (above 90°F at night), soil is too dry, or the plant is stressed. It can also mean the plant is getting too much nitrogen. may support consistent watering, mulch to keep roots cool, and avoid over-feeding with high-nitrogen fertilizer.
When should I stop pruning suckers?
Stop pruning suckers about four to six weeks before your first expected frost. At that point, let the plant focus on ripening existing fruit rather than producing new growth. Pinching off new growth late in the season wastes energy that could go into fruit development.
Can I save seeds from my tomato plants?
Yes, but only from heirloom or open-pollinated varieties. Hybrid tomatoes will not produce seeds that grow into the same plant. Scoop seeds and pulp into a jar, ferment for two to three days to remove the gel coating, rinse, dry completely on a plate, and store in a cool, dry place.