Plant tomatoes in Houston between late February and early March for spring harvest, or in late July and August for fall harvest

Houston's warm climate means you can grow tomatoes twice a year, but the timing is opposite to most of the country. Spring planting happens when other regions are still frozen — you start seeds indoors in January or buy transplants in February, then move them outside in late February or early March. Fall planting, which many Houston gardeners prefer because summer heat stresses tomato plants, begins in late July or August when you sow seeds directly or transplant seedlings.

The reason for these windows is Houston's heat and humidity. Tomatoes stop setting fruit when nighttime temperatures stay above 75°F, which happens by May in Houston and lasts until September. A spring crop produces heavily in April and May, then slows or stops. A fall crop planted in August produces from October through December, avoiding the worst summer heat entirely.

Key Takeaways

  • Spring tomatoes go in the ground in late February or early March as transplants, after the last frost date of January 30.
  • Fall tomatoes are planted in late July or August and produce from October through the first frost, usually in December.
  • Houston's summer heat (May through September) stops tomato plants from setting fruit, so fall planting avoids this dead zone.
  • Start spring seeds indoors in January, or buy transplants from a nursery in February to skip the seed stage.
  • Fall crops need less water and pest management than spring crops because cooler weather arrives as plants mature.

Spring Planting: Late February Through Early March

For a spring crop, plant transplants outdoors between February 20 and March 10. This window comes after Houston's last frost date (January 30) but before the heat climbs high enough to stress young plants. Transplants are seedlings already 6 to 8 weeks old, with a few true leaves and a sturdy stem — they go straight into the ground and start producing within 8 to 10 weeks.

If you want to start from seed, sow indoors in early January under grow lights or on a sunny windowsill. Keep soil warm (70°F to 75°F) and moist. Seedlings emerge in 5 to 10 days. By late February, they will be ready to harden off (move outside for a few hours each day for a week) and then transplant into the garden. Most Houston gardeners skip this step and buy transplants from a local nursery in February — it is faster and the plants are already acclimated to local conditions.

Spring crops produce heavily in April and May, then slow down as nighttime temperatures climb. By June, fruit set drops sharply. You will still get tomatoes through July, but yields decline. Plan for 8 to 12 weeks of good production from a spring planting.

Fall Planting: Late July and August

Fall planting is the better choice for Houston gardeners who want a longer, more reliable harvest. Plant seeds directly in the garden or transplants in late July or August. Direct seeding (pushing seeds into the soil) works well in fall because soil is warm and germination is fast — seeds sprout in 5 to 7 days. Transplants planted in August will produce from October through December, a 12-week window with steady, heavy yields.

The advantage of fall planting is that temperatures drop as the plant matures. Young plants experience 85°F to 90°F nights in August and September, which is warm but not the 95°F+ heat of June and July. By October, nighttime temperatures fall to 65°F to 70°F, the ideal range for fruit set and ripening. Plants produce continuously through November and into December until the first frost, usually around December 15 to 20.

Fall crops also face fewer pest and disease problems. Spider mites, whiteflies, and fungal diseases are less aggressive in cool weather. You will water less often as temperatures drop. The trade-off is that you must plant early enough — if you wait until September, the plant may not mature before the first frost.

Why Houston's Summer Heat Stops Tomato Production

Tomato plants stop setting fruit when nighttime temperatures stay above 75°F. In Houston, this happens by mid-May and lasts until mid-September — a four-month dead zone. During this period, pollen becomes sterile and flowers drop without forming fruit. The plant keeps growing, but no tomatoes develop. This is why spring crops fade and why summer planting (June or July) fails entirely.

Daytime heat is less of a problem than nighttime heat. A 95°F day with a 70°F night is fine. A 85°F night is the problem. Houston's humidity makes it worse — the air does not cool down at night the way it does inland. This is why fall planting works so well: by the time the plant is mature enough to produce heavily, nighttime temperatures have dropped below 75°F.

Soil Preparation and Watering for Each Season

Before planting in spring, work compost or aged manure into the top 8 inches of soil. Houston soil is often clay-heavy and compacted, so adding organic matter improves drainage and root growth. Mix in a balanced fertilizer (10-10-10 or similar) at the rate on the package. Spring plants need consistent water — about 1 inch per week from rain or irrigation — because they are establishing roots in warming soil.

Fall soil preparation is simpler because the soil is already warm and moist from summer. Add compost if the bed is depleted, but you do not need as much amendment as spring. Fall plants need less water overall because temperatures drop and rainfall increases. Water deeply twice a week in August and September, then once a week as temperatures fall.

Both seasons benefit from mulch — 2 to 3 inches of wood chips or straw around the base of the plant, kept 2 inches away from the stem. Mulch keeps soil cool in spring and retains moisture in fall.

Variety Selection for Houston's Two Seasons

Choose determinate (bush) or indeterminate (vining) varieties based on your space and how long you want to harvest. Indeterminate varieties like 'Sungold', 'Cherokee Purple', and 'Brandywine' produce continuously and are better for fall planting, where you have 12 weeks to harvest. Determinate varieties like 'Roma' and 'San Marzano' produce most of their fruit in a short window and are fine for spring, where production slows by June anyway.

Heat-tolerant varieties perform better in spring. Look for 'Heatwave II', 'Surefire', or 'Phoenix' — these set fruit even when nights are warm. For fall, any variety works because temperatures are cool by harvest time. Cherry tomatoes like 'Sungold' and 'Sweet 100' are reliable in both seasons.

Frequently Asked Questions

Can I plant tomatoes in June or July in Houston?

No. Soil temperatures are too high and nighttime temperatures are above 75°F, so seeds will not germinate reliably and transplants will not set fruit. Wait until late July or August for fall planting. If you want a summer harvest, plant in late February for spring production instead.

What is the first frost date in Houston?

The average first frost date in Houston is December 15 to 20. Fall tomatoes planted in August will produce until this date. If you live in a warmer part of Houston (closer to the coast), frost may come later; if you are inland, it may come earlier. Check your specific zip code with the National Weather Service.

Do I need to prune tomato plants in Houston?

Pruning is optional. Removing suckers (shoots that grow between the main stem and branches) on indeterminate varieties directs energy into fruit production and improves air flow, which helps prevent fungal disease in humid Houston. Determinate varieties need less pruning. Prune in early morning when the plant is dry.

How much sun do tomatoes need in Houston?

Tomatoes need at least 6 to 8 hours of direct sun per day. In spring, full sun is fine. In summer, afternoon shade (from a tree or shade cloth) can keep plants cooler, but it reduces fruit production. For fall crops, full sun is ideal because cooler temperatures are not a problem.

What pests should I watch for in Houston?

Spider mites, whiteflies, and hornworms are common in spring. Fall crops face fewer pests. Check plants twice a week for damage. Spray with insecticidal soap or neem oil if you see pests, following label directions. Remove affected leaves by hand when possible.