Tomato Solanum lycopersicum

Reviewed June 2026 · how we check this

The backyard garden's signature crop — a frost-tender, sun-loving annual grown for sweet to tangy fruit on either sprawling vines (indeterminate) or compact bushes (determinate). Easy to start, generous in return, and endlessly forgiving once the roots are established.

Light

Tomatoes are sun engines — give them a minimum of 6 hours of direct sun, and 8 or more for the heaviest fruit set and sweetest flavor. Skimp on light and you'll get tall, spindly, pale plants that flower poorly and ripen slowly. Pick the brightest, most open spot in the garden, away from the shade of buildings, fences, or tall crops. In very hot, intense-sun regions (Zones 9–10) a little afternoon shade during a heat wave can actually prevent sunscald on the fruit, but for most gardeners, more sun is simply better. Seedlings grown indoors need a bright grow light kept just inches above them to stay stocky rather than leggy.

Watering

Tomatoes want deep, consistent moisture — roughly 1–2 inches per week, more in heat. Water deeply at the base 2–3 times a week rather than a daily splash; this drives roots down and builds drought resilience. Keep foliage dry to discourage fungal disease, and water in the morning. Consistency matters more than volume: erratic wet-then-dry swings cause blossom-end rot and split fruit. A 2–3 inch mulch of straw or shredded leaves conserves moisture and steadies soil temperature. Containers dry out fast and may need daily watering at peak summer. Ease off slightly as fruit ripens to concentrate flavor.

Soil & potting

Plant in rich, well-drained loam generously amended with compost or aged manure; aim for a slightly acidic pH of 6.2–6.8. Tomatoes are heavy feeders, so work several inches of organic matter into the bed before planting. Plant seedlings deep — bury two-thirds of the stem, including the lowest leaf nodes, and the buried stem will sprout new roots for a sturdier plant. A raised bed warms early and drains well, which tomatoes love. In containers, use at least a 5-gallon pot with quality mix and reliable drainage. Avoid planting where tomatoes, peppers, or potatoes grew the previous year to limit soilborne disease.

Humidity & temperature

Tomatoes are warm-season annuals killed by frost, so timing to your last frost is everything. They set fruit best between 65–85°F; below 55°F growth stalls, and above 90°F daytime (or 75°F nighttime) blossoms drop without setting fruit. In humid climates, space plants generously and prune lower leaves for airflow to fend off blight and leaf spot. Cool, damp regions favor early, blight-resistant varieties; hot regions favor heat-set types. Protect transplants from late cold snaps with frost cloth, and at season's end a cover can stretch the harvest a week or two past the first light frost.

Fertilizing

Tomatoes are hungry. Mix a balanced or slightly phosphorus-forward fertilizer into the planting hole, then switch to regular feeding once fruit begins to set. A liquid tomato or vegetable fertilizer every 2–3 weeks through the growing season keeps production strong. Avoid heavy nitrogen — it grows lush green foliage at the expense of fruit. Calcium-rich amendments and steady watering together prevent blossom-end rot. Container plants exhaust nutrients quickly and benefit from lighter, more frequent feeding. Stop or reduce feeding late in the season to let the plant pour energy into ripening rather than new growth.

Pruning & maintenance

Indeterminate (vining) types benefit from pruning: pinch out the small 'suckers' that form in the crotch between the main stem and side branches to focus energy on fewer, larger fruit, and train the plant up a stake, cage, or string. Determinate (bush) types should be left largely unpruned, as they set their whole crop on existing growth. Remove yellowing or diseased lower leaves to improve airflow and reduce splash-borne disease. Late in the season, topping an indeterminate plant directs its remaining energy into ripening the fruit already on the vine.

Propagation

Tomatoes are grown from seed, started indoors about 6 weeks before your last spring frost. Sow seeds 1/4 inch deep in moist seed-starting mix, keep them at 70–80°F (a heat mat speeds germination to 5–10 days), and grow under bright light to prevent legginess. Pot up once true leaves appear. Harden seedlings off over a week of increasing outdoor exposure, then transplant after all danger of frost has passed and nights stay above 50°F. You can also clone a favorite plant: a cut sucker placed in water roots within days. Save seed from open-pollinated (not hybrid) fruit for next year.

Through the year

Spring

Start seeds indoors ~6 weeks before last frost; harden off and transplant deep once frost danger passes and nights stay above 50°F.

Summer

Peak growth and harvest — water deeply and evenly, feed every 2–3 weeks, prune suckers on vining types, and pick ripe fruit often.

Fall

As nights cool, stop feeding, top indeterminate plants to ripen remaining fruit, and cover with frost cloth to extend the harvest.

Winter

Out of season in most zones — plan next year's varieties, refresh beds with compost, and order seed.

Companion planting

Classic companions: basil, marigold, nasturtium, carrots; keep away from brassicas and fennel.

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