February 28, 2026

When to Plant Tomatoes in Zone 8

Zone 8 spans the Deep South, much of Texas, the Pacific Northwest coast, and parts of the Southwest. It's a big zone with a lot of climatic variety, but the common thread is mild winters and long, warm growing seasons — 220+ frost-free days in most locations.

For tomatoes, zone 8 is both a blessing and a headache. The season is long enough to grow almost anything, but summer heat can be brutal. Timing your planting to front-load production before the heat takes over is the key to a huge harvest.

Zone 8 planting dates

Yes, that means zone 8b gardeners are starting tomato seeds in January. If that sounds aggressive, it is — but it's how you get ripe tomatoes by Memorial Day.

The heat problem

Tomatoes set fruit when nighttime temperatures are between 55°F and 75°F. Once nights stay above 75°F — which happens across much of zone 8 from late June through August — the plants grow fine but stop producing fruit. Flowers drop. Existing green fruit ripens, but nothing new forms. For more details, see our guide on When to plant tomatoes by zone.

This is why early planting matters so much in zone 8. You're racing to get as many fruit set as possible before the heat wall hits. Every week of earlier planting means another week of production. For more details, see our guide on When to Plant Tomatoes in Zone 5.

Heat-tolerant varieties

The fall crop

Here's the zone 8 bonus: you can plant a second crop. Start seeds indoors in mid-June, transplant in late July, and harvest from September through November (or even December in 8b). The fall crop avoids the worst summer heat and produces in the cooler, gentler conditions of autumn.

For the fall crop, stick with varieties under 75 days to maturity. You want them producing before frost, and the shorter days of October slow ripening.

Zone 8 Pacific Northwest vs. Southeast

Zone 8 in Portland, Oregon is very different from zone 8 in Dallas, Texas. The temperatures may average the same annually, but the patterns are opposite:

• PNW zone 8: Mild summers (rarely above 95°F), long but cool. Heat isn't the issue — getting enough warmth is. Use black plastic mulch, choose early varieties, and don't transplant until soil hits 60°F (usually late April/early May despite the March frost date).
• Southeast zone 8: Hot, humid summers. Heat tolerance is everything. Plant early, mulch heavily, use shade cloth in July-August, and plan for a fall crop.
• Southwest zone 8: Hot and dry. Similar to Southeast strategy but with more intense sun. Shade cloth is essential, and irrigation demands are high.

Practical tips for zone 8

1. Mulch like your harvest depends on it — because it does. 4-6 inches of organic mulch keeps roots cool and conserves water during the long, hot summers.
2. Water deeply, not often. Deep watering (1-2 inches per week) encourages deep roots. Daily light watering creates shallow roots that stress easily.
3. Plant in afternoon shade if possible. A spot that gets morning sun and afternoon shade produces better through summer than full-sun-all-day.
4. Don't give up in August. The plants look rough, but they're alive. When temps drop in September, they'll bounce back and produce through fall.

Use the planting calendar to pin down your exact dates based on zip code. For a broader view, the spring planting schedule covers all the major crops alongside tomatoes.