How to grow tomato
Family Solanaceae. Hardy to USDA hardiness zone 3a+ (U.S. Department of Agriculture). Full sun, 8+ hrs. Ready in 60-85 days.
Sun
Full sun, 8+ hrs
Spacing
24-36 in
Days to harvest
60-85 days
Hardiness
Zone 3a+
What growers actually recorded
Loading zone 7b results…
When to plant tomato
- Start indoors: ~6 weeks before last frost.
- Transplant out: ~2 weeks after last frost.
Companion plants for tomato
Plant with: Basil, Marigold, Carrot, Onion.
Avoid near: Brassicas, Fennel, Corn.
Common pests & problems
Hornworm, aphids, blight. Rotate 3-year cycle to break disease.
Feeding & fertilizer
N-P-K ratio: Low N (5-10-10) once fruiting starts
Organic options: Compost 2-3 in. at planting · Fish emulsion every 2 wks while young · Bone meal + kelp at flowering for calcium/potassium
When to feed: Compost at planting → light nitrogen through vegetative → switch to P/K when flowers appear.
Watch for: All leaves, no fruit = too much N. Blossom-end rot = calcium deficit + uneven watering.
N = nitrogen (leaves), P = phosphorus (roots and flowers), K = potassium (fruit and disease resistance). How to read a fertilizer label →
Grower's tip
Bury 2/3 of the transplant stem. Roots form along the buried stem for a stronger plant.
When to plant tomato in your zone
Free month-by-month sowing and transplanting lists, built from frost dates for your USDA (United States Department of Agriculture) hardiness zone.
Soil & water for tomato
Soil & pH
6.2-6.8: slightly acidic
Loose, deep loam. Break up compaction 12 in down; tomatoes and peppers root deeply when given the room.
Work 2-3 in of compost + a handful of bone meal per plant into the hole. Warm soil to 60°F+ before transplanting; black plastic mulch 2 weeks ahead helps in the North.
Watering
1-1.5 in / week, more in fruit set
Deep soak at the base twice a week. Drip or soaker hose beats overhead watering: wet leaves invite early blight.
Stick your finger 4 inches in near the stem. If it's dry at the second knuckle, water. If it's still damp, wait. Flipping from bone-dry to soaked is what cracks fruit and brings on blossom-end rot.
Knowing when to harvest
- Full color (variety-specific) with a slight give at the shoulder.
- Twist-and-lift; ripe fruit separates cleanly at the stem.
- In frost country: pick all mature-green fruit before first frost and ripen indoors at 55-70°F.
Storing & keeping
Never refrigerate. Cold destroys flavor compounds. Counter-store stem-up at 55-70°F for 5-7 days. Freeze whole or can (pressure or water-bath with added lemon juice, pH < 4.6).
What to expect
Per plant: 10-30 lb indeterminate; 5-15 lb determinate
Per sq ft: ~2 lb / sq ft trellised
For most home gardeners, 10-15 lb per plant is a solid win; 20+ lb is master-level territory. JM Fortier's benchmark for intensive market growers is 3-4 kg/m².
Troubleshooting tomato
Blossom-end rot (black, sunken bottom)
Likely cause: Calcium can't reach the fruit. Almost always from uneven watering, not calcium deficit
What to do: Mulch 3 in deep, water 1.5 in weekly on a fixed schedule. Calcium spray is a last resort.
Cracked or split fruit
Likely cause: Heavy water after a dry spell
What to do: Even soil moisture; mulch. Pick fruit at first blush during rainy stretches.
Curled leaves + purple veining
Likely cause: Cool nights (< 55°F) or phosphorus lockout in cold soil
What to do: Wait for warmer weather; foliar kelp helps.
Yellow lower leaves with dark rings
Likely cause: Early blight (Alternaria)
What to do: Remove infected leaves, mulch to stop soil splash, spray Serenade or copper weekly.
Varieties worth growing
Sungold (indeterminate cherry)
The sweetest small tomato most gardeners will ever grow. Vigorous and crack-resistant.
Cherokee Purple (heirloom slicer)
Complex flavor and reliable in humid climates when staked.
Roma / San Marzano (paste)
Meaty, low-seed; the choice for sauce and canning.
Defiant PhR (hybrid slicer)
Bred for late-blight resistance; a rescue variety for wet climates.
Growing tomato in containers
5-gallon minimum for determinates; 10-gallon (grow-bag or half-barrel) for indeterminates. Stake or cage at planting: root disturbance later cuts yield.
Nutrition
High in lycopene (tomato), capsaicin (hot pepper), vitamin C, and potassium.
Common questions
Do I really need to prune suckers?
On indeterminates trained to a single stem, yes. You'll get earlier, cleaner fruit. On determinate bush types, no; you'll cut into yield.
Why won't my tomatoes turn red?
Above 85°F, tomatoes stop producing lycopene. Provide 30% shade cloth and pick at first blush to ripen indoors.
Can I plant tomatoes in the same spot each year?
Not if you can help it. Rotate on a 3-year cycle to break early blight, Fusarium, and Verticillium wilt cycles.
Where these numbers come from
- USDA Plant Hardiness Zone Map (2023 revision). Zone assignment and the 30-year normals behind every cold-hardiness figure.
- NOAA NCEI 1991-2020 Climate Normals. Frost dates, growing-season length, and the probability bands on both.
- Cornell, UMN, and UC Davis Cooperative Extension crop guides. Spacing, days to maturity, soil pH targets, and per-plant yield ranges.
- USDA FSIS / FDA Produce Safety guidance. Wash, cure, and cold-storage handling numbers.
Ranges are regional guidance, not a promise for your yard. Your own logged results always override the published range.