Water deeply and consistently, not daily
Tomato plants need about 1 to 2 inches of water per week, delivered in one or two deep soakings rather than daily sprinkles. Water at the base of the plant, not on the leaves—wet foliage invites fungal disease. The soil should feel moist 2 to 3 inches down; if it's soggy or cracked dry, you've gone too far in one direction.
The best time to water is early morning, so any splash on leaves dries quickly. If you use a soaker hose or drip line, you'll lose less water to evaporation and keep the leaves dry at the same time. During hot spells or when plants are heavy with fruit, they may need water twice a week. During cool, rainy weeks, you may skip a week entirely.
Inconsistent watering causes problems like blossom-end rot (a dark, sunken spot on the bottom of the fruit) and fruit cracking. A thick layer of mulch—2 to 3 inches of straw or shredded leaves—keeps soil moisture steady and reduces how often you need to water.
Key Takeaways
- Water at the soil level, not the leaves, once or twice a week for a total of 1 to 2 inches, and mulch to keep moisture consistent.
- Prune suckers (shoots that grow between the main stem and branches) on indeterminate varieties to direct energy into fruit rather than foliage.
- Feed every two to three weeks with a balanced fertilizer once the plant flowers, or use a slow-release fertilizer at planting time.
- Watch for yellowing leaves, brown spots, or soft spots on fruit—these signal disease or pest problems that need quick attention.
- Support the plant with a cage or stake from the start so the stem doesn't break under the weight of ripening fruit.
Support the stem with a cage or stake early
Tomato plants grow heavy once fruit sets. A cage or stake installed at planting time prevents the stem from snapping and keeps fruit off the ground, where it rots or gets eaten by slugs and insects. Cages work well for determinate varieties (bush types that stop growing at a set height); stakes work better for indeterminate varieties (vining types that grow all season).
If you use a cage, choose one at least 5 feet tall for indeterminate plants—most store cages are too short. If you stake, drive a 6- to 8-foot stake into the ground at planting and tie the stem loosely with soft cloth or garden twine every 8 to 12 inches as the plant grows. Tie in a figure-eight pattern so the twine doesn't cut into the stem.
Installing support early is easier than trying to stake a plant that's already sprawling and heavy. It also makes pruning and harvesting simpler because you can see the fruit and branches clearly.
Prune suckers on vining varieties to focus energy on fruit
Suckers are shoots that grow in the angle between the main stem and a branch. On indeterminate (vining) tomatoes, removing them directs the plant's energy into producing and ripening fruit rather than endless foliage. On determinate (bush) varieties, pruning is optional—they're naturally compact.
Pinch off suckers when they're small, ideally less than 2 inches long, by snapping them off with your fingers or a clean knife. Do this every week or two during the growing season. Stop pruning about four weeks before your first expected frost, so the plant can focus on ripening the fruit already on the vine rather than growing new branches.
Don't remove the main stem or the branches that hold flowers and fruit. The goal is to thin the plant so air flows through it, which also reduces disease. If you remove too much foliage, you expose the fruit to sunscald—a pale, papery patch where the sun burns the skin directly.
Feed the plant every two to three weeks once flowers appear
Tomatoes are heavy feeders. If you mixed compost or slow-release fertilizer into the soil at planting, the plant will have nutrients for the first month or so. Once flowers appear, feed every two to three weeks with a balanced fertilizer (equal parts nitrogen, phosphorus, and potassium) or a tomato-specific formula.
Follow the label directions for the product you choose—dilute liquid fertilizers in water, or sprinkle granular types around the base and water in. Too much nitrogen pushes leafy growth at the expense of fruit; too little phosphorus or potassium weakens the plant and produces small, pale fruit.
Calcium deficiency causes blossom-end rot. If you see this problem, add crushed eggshells or a calcium supplement to the soil and water deeply. Consistent watering also helps because calcium moves through the plant in water.
Watch for common pests and diseases
Tomato plants attract hornworms, aphids, spider mites, and whiteflies. Hornworms are large green caterpillars that eat leaves and fruit; pick them off by hand or spray with neem oil. Aphids and whiteflies cluster on the undersides of leaves and cause yellowing; spray the undersides with insecticidal soap or a strong water spray to dislodge them.
Fungal diseases like early blight (brown spots with concentric rings on lower leaves) and powdery mildew (white coating on leaves) thrive in humid, crowded conditions. Prune lower leaves once the plant is established, space plants 24 to 36 inches apart, water at the base only, and mulch to prevent soil from splashing onto leaves. If disease appears, remove affected leaves and spray with a fungicide labeled for tomatoes.
Bacterial wilt and fusarium wilt cause sudden wilting even when soil is wet; there is no cure, so remove the plant and dispose of it in the trash, not the compost. Rotate where you plant tomatoes each year to avoid soil-borne diseases.
Harvest fruit at the right stage and ripen it indoors if needed
Tomatoes ripen from the inside out. You can pick them when they show color (called the "breaker stage") and ripen them indoors at room temperature, or wait until they're fully red on the vine. Vine-ripened fruit has more flavor, but picking at the breaker stage lets you harvest before frost or pests damage the fruit.
Gently twist and lift the fruit, or cut the stem with pruners. Store ripe tomatoes at room temperature, not in the refrigerator—cold breaks down flavor and texture. If you picked green tomatoes before frost, place them in a paper bag with a ripe banana or apple (which release ethylene gas) and they'll ripen in a few days to a week.
Stop watering and feeding about four weeks before your first expected frost to encourage the plant to ripen remaining fruit rather than grow new flowers. Pinch off new flowers that appear late in the season so the plant doesn't waste energy on fruit that won't have time to mature.
Know when to call a professional
Most tomato problems you can handle yourself—watering, feeding, pruning, and picking off pests are straightforward. If you're unsure whether a disease is fungal or bacterial, or if a pest problem spreads despite your efforts, contact your local cooperative extension office. They can identify the problem from a photo or a sample leaf and recommend treatment specific to your region.
If you're growing tomatoes in containers and they're not thriving despite consistent care, the issue is often soil quality or pot size. Tomatoes need at least 5 gallons of soil per plant; smaller pots dry out too fast and don't hold enough nutrients. Repot into fresh potting mix and the plant usually recovers within a week or two.
Frequently Asked Questions
Why are my tomato leaves turning yellow?
Yellow lower leaves are normal as the plant matures—remove them to improve air flow. Yellow leaves higher up signal nitrogen deficiency (feed the plant), overwatering (let soil dry slightly between waterings), or disease. Check the undersides for pests or spots. If spots are present, it's likely early blight; remove the affected leaves and spray with fungicide.
Can I grow tomatoes in a pot?
Yes, but use a pot at least 5 gallons (20 liters) per plant and fill it with potting mix, not garden soil. Potting mix drains better and holds nutrients longer. Water more often than in-ground tomatoes because pots dry faster. Feed every two weeks because nutrients wash out with watering. Determinate (bush) varieties work better in pots than indeterminate (vining) types.
What's the difference between determinate and indeterminate tomatoes?
Determinate varieties grow to a set height (usually 3 to 4 feet), produce most of their fruit at once, and stop growing. They're good for canning and small spaces. Indeterminate varieties grow all season (6 feet or taller), produce fruit continuously until frost, and need staking and pruning. They're better for fresh eating over a long harvest.
How do I know when a tomato is ripe?
A ripe tomato is fully colored (red, pink, yellow, or whatever the variety is), feels slightly soft when gently squeezed, and comes off the vine with a light twist. If it's hard or pale, it's not ready. You can pick at the breaker stage (first blush of color) and ripen indoors, but vine-ripened fruit tastes better.
Should I remove all the leaves on my tomato plant?
No. Remove only the lower leaves (up to the first flower cluster) once the plant is established, and remove any diseased or damaged leaves. Leaves make the food the plant needs to grow and ripen fruit. Removing too many leaves exposes fruit to sunscald and weakens the plant.