Start with soil, light, and water — the three things tomatoes need most
Tomato plants grow best in soil that drains well, gets at least six to eight hours of direct sunlight each day, and stays consistently moist but not waterlogged. If you are starting from seed indoors, use seed-starting mix (not garden soil) in a shallow tray under grow lights or on a sunny windowsill. If you are planting a seedling you bought from a nursery, transplant it into a pot or garden bed with potting soil mixed with compost. Either way, the plant will not produce fruit without enough light and regular watering.
Tomatoes are heavy feeders, meaning they pull a lot of nutrients from the soil as they grow. Mix a balanced fertilizer into the soil before planting, or use compost worked into the top few inches. Once the plant is growing, feed it every two to three weeks with a tomato-specific fertilizer or a balanced all-purpose formula diluted to half strength. Stop fertilizing once the plant starts flowering heavily, or you will get leaves instead of fruit.
Key Takeaways
- Tomatoes need six to eight hours of direct sun daily, well-draining soil, and consistent moisture to produce fruit.
- Start seeds indoors six to eight weeks before your last spring frost, or buy seedlings and transplant them when they have two to four true leaves.
- Bury the stem deeper than it was growing in the pot — tomatoes will root along the buried stem and grow a stronger plant.
- Prune suckers (shoots that grow between the main stem and branches) on indeterminate varieties to direct energy toward fruit instead of leaves.
- Pick tomatoes when they are fully colored but still slightly firm, or pick them green and ripen them indoors if frost is coming.
Timing: when to plant seeds or seedlings outdoors
Tomato seeds germinate in seven to ten days at room temperature (around 70°F), but they grow faster and stronger under grow lights or on a very sunny windowsill. Start seeds indoors six to eight weeks before your last spring frost date. You can find your frost date by searching "[your city] last spring frost" — it varies by region and changes year to year.
Transplant seedlings outdoors only after the soil has warmed to at least 60°F and nighttime temperatures stay above 50°F. Cold soil and cold nights stunt growth and can kill young plants. If you buy seedlings from a nursery, harden them off first by setting them outside in shade for a few hours, then gradually moving them into sun over five to seven days. This prevents sunburn and shock.
Planting depth and spacing matter more than most gardeners think
Bury tomato seedlings deeper than they were growing in their pot — up to the first set of true leaves. Tomatoes will sprout roots all along the buried stem, creating a stronger root system that can reach water deeper in the soil and support a heavier plant. This is one of the few times deeper planting is better than shallow.
Space plants 24 to 36 inches apart, depending on the variety. Determinate varieties (bush types that grow to a fixed size) can be closer; indeterminate varieties (vining types that keep growing all season) need more room for air circulation. Good air flow reduces disease, especially fungal problems like early blight and powdery mildew. If you are planting in containers, use a pot at least 5 gallons for determinate varieties and 10 gallons for indeterminate types.
Watering: the difference between a good crop and a failed one
Water deeply and consistently — aim for one to two inches per week, either from rain or from you. Water at the base of the plant in the morning, not from overhead, because wet leaves invite fungal disease. Stick your finger into the soil; if it is dry an inch down, water. If it is still moist, wait another day or two.
Inconsistent watering causes problems that no amount of fertilizer will fix. Too little water stresses the plant and invites spider mites; too much causes root rot and splits the fruit. Mulch around the base with two to three inches of straw or wood chips to keep the soil temperature steady and reduce how often you have to water. Keep mulch a few inches away from the stem to prevent rot.
Pruning and support: keeping the plant upright and productive
Indeterminate tomatoes (the vining kind) need support — a cage, stake, or string tied to an overhead beam. Install support at planting time, before the roots spread and get damaged. Determinate varieties are bushier and more compact, but they still benefit from a cage to keep fruit off the ground and away from pests and disease.
On indeterminate varieties, remove suckers — the shoots that grow in the angle between the main stem and a branch. Suckers do not produce fruit; they just steal energy and create a dense tangle that traps moisture. Pinch them off by hand when they are small, or cut them with pruning shears. On determinate varieties, pruning is less critical because the plant naturally stops growing, but removing a few lower leaves once fruit sets improves air flow.
Harvest timing: when to pick and how to ripen green tomatoes
Pick tomatoes when they are fully colored but still slightly firm — they will continue to ripen off the vine. Leaving them on the plant until they are soft wastes energy the plant could use to ripen other fruit. If frost is coming and you have green tomatoes still on the vine, pick them all. They will ripen indoors in a paper bag or on a windowsill at room temperature within one to three weeks.
A single plant can produce 10 to 30 pounds of fruit over the season, depending on variety, weather, and care. Harvest regularly — the more you pick, the more the plant produces. Stop harvesting about four weeks before the first fall frost so the plant can focus energy on ripening the remaining fruit instead of setting new flowers.
Common problems and how to prevent them
Blossom end rot appears as a dark, sunken spot on the bottom of the fruit and is caused by inconsistent watering and calcium deficiency. Prevent it by watering steadily and adding crushed eggshells or gypsum to the soil before planting. Early blight shows up as brown spots with concentric rings on lower leaves and spreads upward; remove affected leaves and improve air flow by pruning and spacing plants farther apart.
Hornworms are large green caterpillars that can strip a plant bare in days. Hand-pick them or spray with spinosad (an organic insecticide) if the infestation is heavy. Spider mites thrive in hot, dry conditions; mist the leaves with water in the morning or use neem oil spray. Powdery mildew looks like white dust on leaves; prevent it with good air flow and avoid overhead watering.
Frequently Asked Questions
Can I grow tomatoes in a container on a patio or balcony?
Yes. Use a pot at least 5 gallons for determinate varieties and 10 gallons for indeterminate types, with drainage holes in the bottom. Fill it with potting soil mixed with compost, place it where it gets six to eight hours of direct sun, and water when the top inch of soil is dry. Container plants dry out faster than garden plants, so you may need to water daily in hot weather.
What is the difference between determinate and indeterminate tomatoes?
Determinate varieties grow to a fixed size (usually 3 to 4 feet), produce most of their fruit at once, and stop growing. Indeterminate varieties keep growing and producing fruit all season until frost kills them. Determinate types are good for canning or sauce-making; indeterminate types are better if you want fresh tomatoes throughout the summer.
How long does it take from planting to first harvest?
From seed to first ripe tomato takes about 70 to 85 days, depending on variety. If you start seeds indoors six to eight weeks before the last frost and transplant outdoors after frost danger passes, you will usually have ripe fruit by mid to late summer. Buying seedlings from a nursery cuts two to three weeks off that timeline.
Do I need to use fertilizer, or is compost enough?
Compost alone works if your soil is already rich, but most garden soils benefit from additional fertilizer. Mix a balanced formula into the soil before planting, then feed every two to three weeks once the plant is growing. Tomato-specific fertilizers are formulated for the nutrient ratios tomatoes need, but a balanced all-purpose fertilizer diluted to half strength works too.
What should I do if my tomato plant has flowers but no fruit?
Flowers drop without setting fruit when nighttime temperatures drop below 55°F or rise above 75°F, or when the plant is stressed by too much nitrogen fertilizer. If temperatures are the problem, wait — fruit will set once temperatures stabilize. If you have been over-fertilizing, stop and switch to a lower-nitrogen formula or stop feeding altogether until fruit appears.