Start with soil that drains well and holds nutrients
Tomato plants need soil that lets water pass through but keeps enough moisture for the roots to absorb. The best mix for containers or garden beds is roughly 40 percent compost, 30 percent peat moss or coconut coir, and 30 percent perlite or coarse sand. If you are planting directly in garden soil, work in 2 to 3 inches of compost before planting to improve drainage and add organic matter.
Soil pH should sit between 6.0 and 6.8—slightly acidic. You can test your soil with an inexpensive kit from a garden center or send a sample to your local cooperative extension office, which will test it free or for a small fee. If your soil is too alkaline, add sulfur. If it is too acidic, add lime. Both take several weeks to shift the pH, so amend the soil in spring before planting.
Key Takeaways
- Tomato plants need at least 6 to 8 hours of direct sunlight daily, and 10 to 12 hours is better for faster growth and more fruit.
- Water deeply at the soil level once or twice a week rather than shallow daily watering, which encourages disease and weak roots.
- Prune suckers (shoots that grow between the main stem and branches) on indeterminate varieties to direct energy into fruit instead of foliage.
- Support plants with cages, stakes, or trellises from the time they are young so you do not damage roots later by driving stakes into the ground.
- Feed every two to three weeks with a balanced fertilizer once flowers appear, switching to lower nitrogen after the first fruit sets.
Give plants 6 to 8 hours of direct sun, ideally more
Tomatoes are sun-hungry. Six to eight hours of direct sunlight is the minimum; 10 to 12 hours produces faster growth, more flowers, and more fruit. If you are growing in containers, place them where they get morning sun—this dries dew from the leaves and reduces fungal disease. Afternoon shade in very hot climates (above 90°F regularly) can prevent sunscald on the fruit, but do not sacrifice morning light to get it.
If your garden gets less than 6 hours of direct sun, tomatoes will grow slowly, produce fewer flowers, and the fruit that does form will be less sweet. Indeterminate varieties (the tall, sprawling types) tolerate partial shade better than determinate ones (compact, bushy types), but neither will thrive in shade. If your space is limited, choose a sunny spot and grow in containers so you can move them if needed.
Water at soil level, not from above, once or twice weekly
Watering from above—spraying the leaves—creates wet foliage that invites fungal diseases like early blight and powdery mildew. Instead, water at the base of the plant, directing water to the soil. Water deeply enough that the soil is moist 6 to 8 inches down. In most climates, this means watering once or twice a week rather than a little bit every day.
Shallow daily watering keeps the top inch wet but leaves deeper roots dry, so the plant stays stressed and weak. Inconsistent watering—wet one week, dry the next—causes blossom-end rot (a dark, sunken spot on the bottom of the fruit) because calcium cannot move into the fruit when water supply is erratic. Use a soaker hose or drip line if you can; both deliver water slowly to the soil and reduce disease pressure. If you hand-water, do it early in the morning so any splash on leaves dries quickly.
Support plants with stakes or cages early, before they get heavy
Determinate tomatoes (bush types) usually need a cage or short stake. Indeterminate tomatoes (vining types) need a tall stake, trellis, or sturdy cage—they can grow 6 feet or taller. Install support when you plant or within a week or two, while the plant is still small. Driving a stake into the ground near a mature plant damages roots and stresses the plant.
Tie the stem loosely to the support with soft ties—old cloth strips, plant tape, or commercial velcro ties work well. Tie in a figure-eight pattern so the tie does not cut into the stem as it grows. Check ties every two weeks and loosen them as the stem thickens. A plant that falls over or bends under its own weight will crack, split, or break branches, and the fruit touching the ground will rot.
Prune suckers on indeterminate varieties to focus energy on fruit
Indeterminate tomatoes grow continuously and produce shoots called suckers that sprout between the main stem and the branches. These suckers will grow into full branches if left alone, creating a dense, leafy plant that shades the fruit and reduces air circulation. Removing suckers directs the plant's energy into flowering and fruiting instead of making more leaves.
Pinch off suckers when they are small—1 to 2 inches long—by snapping them off with your fingers. Do this once a week during the growing season. Determinate (bush) tomatoes produce fewer suckers and do not need pruning. If you are unsure whether your variety is determinate or indeterminate, check the seed packet or plant label; it will say "determinate," "indeterminate," or "semi-determinate."
Feed plants every two to three weeks once flowers appear
Tomatoes are heavy feeders. Before planting, mix a balanced fertilizer (like 5-5-5 or 10-10-10) into the soil according to package directions. Once the plant flowers, feed every two to three weeks with a liquid or granular fertilizer. A balanced formula works at first, but once the first fruit sets, switch to a lower-nitrogen formula (like 5-10-10) to encourage fruiting rather than leaf growth.
Nitrogen-heavy fertilizers produce lots of green leaves but few flowers. Phosphorus and potassium promote flowering and fruiting. Organic options include fish emulsion, seaweed extract, and compost tea. Synthetic options include Miracle-Gro or Jobe's Organics. Follow the label directions for rate and frequency—more fertilizer does not mean faster growth and can burn roots or create salt buildup in the soil.
Watch for common pests and diseases, and act early
The most common tomato diseases are early blight (brown spots with concentric rings on lower leaves), late blight (water-soaked spots on leaves and fruit), and powdery mildew (white coating on leaves). All three thrive in wet conditions. Prevent them by watering at soil level, spacing plants so air flows between them, and removing lower leaves once the plant is established so they do not touch soil.
Common pests include hornworms (large green caterpillars that eat leaves and fruit), aphids (tiny soft-bodied insects that cluster on stems), and spider mites (which cause yellowing and fine webbing). Hand-pick hornworms if you see them. For aphids and spider mites, spray the undersides of leaves with insecticidal soap or neem oil every 7 to 10 days until they are gone. Always spray in early morning or late evening to avoid harming bees.
Harvest fruit when it reaches full color but is still slightly firm
Tomatoes continue to ripen after picking, so you do not have to wait until they are soft. Pick them when they have reached full color for the variety—deep red, orange, yellow, or whatever color yours should be—but are still slightly firm to the touch. Ripe fruit comes off the vine with a gentle twist.
If frost is coming and you have green tomatoes still on the vine, pick them and place them in a paper bag with a ripe banana or apple. The ethylene gas from the fruit speeds ripening indoors. Store ripe tomatoes at room temperature, not in the refrigerator, which breaks down flavor and texture. A tomato stored at 68°F will stay good for a week or more; one stored in the fridge will soften and lose taste within days.
Frequently Asked Questions
Why are my tomato flowers dropping off without making fruit?
Flowers drop when the plant is stressed—usually from inconsistent watering, temperatures below 55°F or above 90°F at night, or too much nitrogen fertilizer. may support soil stays evenly moist (not soggy), wait for nighttime temperatures to warm up, and switch to a lower-nitrogen fertilizer once flowers appear.
Can I grow tomatoes in containers?
Yes. Use a container at least 5 gallons for determinate varieties and 10 gallons for indeterminate ones. Fill with potting mix (not garden soil), may support the pot has drainage holes, and water more often than in-ground plants because containers dry out faster. Everything else—sun, fertilizer, pruning, pest management—is the same.
What is blossom-end rot and how do I prevent it?
Blossom-end rot is a dark, sunken spot on the bottom of the fruit caused by calcium deficiency, which happens when watering is inconsistent. Prevent it by watering deeply and regularly so soil moisture stays even. If your soil is very acidic, add lime to raise pH and make calcium available. Affected fruit cannot be saved, but new fruit will be fine if you fix the watering.
Should I remove leaves from my tomato plant?
Remove only the lowest leaves once the plant is 12 inches tall and has several sets of leaves above them. These lower leaves are closest to soil and most likely to catch fungal disease. Do not strip the plant bare—leaves make the food the plant needs to grow and fruit. Remove no more than one-third of the foliage at a time.
When should I stop fertilizing?
Stop fertilizing about 4 to 6 weeks before your first expected frost. At that point, the plant will not have time to ripen new fruit, so feeding just produces more leaves. Focus on ripening the fruit already on the vine by removing new flowers and any new suckers that appear.