Water tomatoes deeply and regularly, 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. Early morning is the best time, so the soil has all day to absorb the water before the sun heats it.
The soil should feel moist 2 to 3 inches down when you push your finger into it. In hot weather or sandy soil, you may need to water twice a week. In cool weather or clay soil, once a week is often enough. Mulch around the base with 2 to 3 inches of straw or wood chips to keep the soil from drying out too fast and to prevent soil from splashing onto the leaves during rain.
Inconsistent watering — dry one week, soaked the next — causes blossom-end rot (a dark, sunken spot on the bottom of the fruit) and fruit cracking. If you cannot water by hand, a soaker hose or drip line on a timer will keep the moisture steady.
Key Takeaways
- Water deeply at the base of the plant once or twice a week, aiming for 1 to 2 inches total, rather than light daily watering.
- Feed tomatoes every two to three weeks with a balanced fertilizer once they start flowering, or use slow-release pellets at planting time.
- Prune suckers (shoots that grow between the main stem and branches) on indeterminate varieties to direct energy into fruit rather than leaves.
- Pick tomatoes when they are fully colored but still slightly firm, or pick green ones at the end of the season and ripen them indoors.
- Watch for yellowing leaves, brown spots, and wilting — these signal overwatering, disease, or nutrient shortage, each with a different fix.
Feed tomatoes every two to three weeks once they flower
Tomatoes are heavy feeders. At planting time, work compost or aged manure into the soil. Once the plant starts to flower, feed it every two to three weeks with a balanced fertilizer — something labeled 10-10-10 or 5-10-5 works well. Liquid fertilizers work faster; granular or pellet fertilizers release slowly over the season.
If you used a slow-release fertilizer pellet at planting, you may not need to feed again until mid-season. If you see yellowing leaves (especially the lower ones) while the plant is still growing, that is a sign of nitrogen shortage — switch to a fertilizer higher in nitrogen, like 20-10-10, for one or two feedings.
Avoid over-feeding with nitrogen late in the season, which produces lots of leaves but few tomatoes. Once the plant is heavy with fruit, switch to a fertilizer higher in phosphorus and potassium (the second and third numbers), like 5-10-10, to push the fruit to ripen and sweeten.
Prune suckers on indeterminate tomatoes to focus energy on fruit
Indeterminate tomatoes (the tall, vining kinds that grow all season) produce shoots called suckers that grow in the angle between the main stem and a branch. These suckers will grow into full branches if left alone, creating a dense, leafy plant that produces fewer tomatoes and ripens them slower. Pinch or cut off these suckers when they are small — less than 3 inches long — to keep the plant open and direct energy into fruit.
Determinate tomatoes (the compact, bushy kinds bred for canning) do not need pruning; they are designed to produce most of their fruit at once. If you are not sure which type you have, check the seed packet or plant label. If it says "determinate" or "bush," leave it alone. If it says "indeterminate" or "vining," prune the suckers.
Prune in the morning when the plant is dry, and wash your hands or dip your pruning tool in a 10 percent bleach solution (one part bleach to nine parts water) between cuts to avoid spreading disease from plant to plant.
Harvest tomatoes when they are fully colored but still firm
Pick tomatoes when they are fully colored — red, pink, yellow, or whatever the variety is — and still slightly firm to the touch. They will continue to ripen off the vine and will taste better than tomatoes picked too early. Gently twist and lift, or cut the stem with pruning shears if the fruit does not come away easily.
At the end of the season, when frost is coming and the plant still has green tomatoes, pick all the mature green ones (the ones that are full-sized but not yet colored). Bring them indoors and set them on a windowsill or in a paper bag with a ripe banana or apple — the ethylene gas from the ripe fruit will speed ripening. They will turn color in one to three weeks.
Do not refrigerate tomatoes until they are fully ripe; cold slows ripening and damages flavor. Once ripe, they can go in the fridge for a few days, but room temperature is better for taste.
Watch for yellowing leaves, brown spots, and wilting
Yellowing leaves at the bottom of the plant while the top stays green usually means overwatering or nitrogen shortage. Check the soil — if it is soggy, cut back on watering and make sure the pot or bed drains well. If the soil is dry, feed with a nitrogen-rich fertilizer.
Brown or black spots on leaves and fruit, especially in wet weather, signal early blight or late blight (fungal diseases). Remove the affected leaves and improve air flow by pruning lower branches and spacing plants farther apart. Water only at the base, never on the leaves. If the problem spreads, spray with a fungicide labeled for tomatoes — sulfur or copper-based products work for early blight; chlorothalonil works for late blight.
Wilting during the day that recovers at night usually means the plant needs water. Wilting that does not recover, combined with yellowing leaves, can signal root disease or a pest like spider mites. Check the undersides of leaves for tiny webs or spots. If you see them, spray with insecticidal soap or neem oil every three to five days until they are gone.
Support tall varieties with stakes or cages to prevent fruit damage
Indeterminate tomatoes grow 6 feet tall or taller and need support to keep the fruit off the ground and the branches from breaking under the weight. A sturdy cage (at least 5 feet tall) or a stake with twine works well. Install the support at planting time, before the roots spread — driving a stake through roots later can damage them.
As the plant grows, tie the main stem loosely to the stake with soft twine or cloth strips every 8 to 12 inches. Leave room for the stem to expand; a tight tie will cut into the stem as it thickens. Cages need less tending but can topple in wind if the plant gets very heavy — anchor them to the ground with stakes or rebar driven through the legs.
Determinate tomatoes are usually compact enough to stand on their own, but a small cage or stake can still help keep fruit off the soil and make harvesting easier.
Frequently Asked Questions
Can I grow tomatoes in a pot, and what size do I need?
Yes. Use a pot at least 5 gallons for determinate varieties and 10 gallons for indeterminate ones. Larger is better — bigger pots hold more soil and stay moist longer. Make sure the pot has drainage holes. Use potting soil, not garden soil, which compacts in a pot and drains poorly.
Why are my tomatoes cracking or splitting?
Cracking happens when the fruit absorbs water too fast after a dry spell — the skin cannot stretch fast enough. Water consistently and deeply rather than light and often. Mulch to keep soil moisture steady. Some varieties crack more easily than others; look for crack-resistant types like 'San Marzano' or 'Amish Paste' if this is a recurring problem.
What is the white powder on my tomato leaves?
That is powdery mildew, a fungal disease. It does not usually kill the plant but can slow growth. Improve air flow by pruning lower branches and spacing plants farther apart. Spray with sulfur or a fungicide labeled for powdery mildew on tomatoes. Water only at the base, never on the leaves.
How long does it take from planting to first tomato?
Most varieties produce fruit 60 to 85 days after transplanting into the garden. Determinate varieties often ripen most of their crop within a short window; indeterminate varieties produce fruit all season until frost. Check the seed packet for the specific variety's days to maturity.
Can I save seeds from my tomatoes?
Yes, but only from heirloom or open-pollinated varieties. Hybrid tomatoes (labeled F1) will not produce seeds that grow true to the parent plant. Scoop seeds and gel into a jar, add a little water, let it ferment for two to three days, rinse well, and dry on a paper towel before storing in a cool, dry place.