When to Plant Tomatoes in Arizona
America's favorite garden vegetable (technically a fruit). Nothing beats a sun-warmed tomato straight off the vine.
The Short Answer
Arizona Frost Dates
Your planting dates depend on which part of Arizona you're in. Here are the frost date ranges by region:
| Region | Zones | Last Frost (Spring) | First Frost (Fall) |
|---|---|---|---|
| Northern Arizona (Flagstaff) | 4b, 5a, 5b, 6a | May 15 - Jun 5 | Sep 15 - Oct 10 |
| Central Arizona (Phoenix) | 9a, 9b, 10a | Jan 15 - Feb 10 | Dec 1 - Dec 20 |
| Southern Arizona (Tucson) | 8b, 9a, 9b | Feb 1 - Feb 25 | Nov 20 - Dec 15 |
Tomatoes Planting Schedule for Arizona
Northern Arizona (Flagstaff) (Zones 4b, 5a, 5b, 6a)
Average last frost: May 15 - Jun 5 · Average first frost: Sep 15 - Oct 10
Central Arizona (Phoenix) (Zones 9a, 9b, 10a)
Average last frost: Jan 15 - Feb 10 · Average first frost: Dec 1 - Dec 20
Southern Arizona (Tucson) (Zones 8b, 9a, 9b)
Average last frost: Feb 1 - Feb 25 · Average first frost: Nov 20 - Dec 15
Growing Tomatoes in Arizona
Tomatoes in Arizona's Climate
Tomato growing in subtropical zones follows an inverted calendar. Plant from September through February for winter-spring harvest. Summer's extreme heat, humidity, and pest pressure overwhelm tomatoes in these zones. Choose heat-tolerant and disease-resistant varieties — Florida 91, Solar Fire, and Everglades are bred for your conditions. This timing feels backward but works beautifully — your January tomatoes will be the envy of the nation.
Soil Considerations for Arizona
Alkaline, mineral-rich desert soils. Low organic matter. Heavy amendment with compost essential. Caliche layers may need to be broken. Make sure soil has warmed to at least 60°F before planting tomatoes outside.
Arizona Climate & Growing Season
Extreme heat in summer lowlands. Two planting seasons in Phoenix — spring and fall (summer is too hot). High elevation has traditional cold-climate seasons. Tomatoes cannot tolerate any frost, so wait until all frost danger has passed before transplanting outside. Watch local forecasts carefully in spring.
Growing season length varies across Arizona: Northern Arizona (Flagstaff) (4b, 5a, 5b, 6a) has a last frost around May 15 - Jun 5, while Southern Arizona (Tucson) (8b, 9a, 9b) sees frost end around Feb 1 - Feb 25. This difference matters for tomatoes — transplant timing shifts by several weeks across the state.
Growing Tips
Pinch off suckers for indeterminate varieties. Stake or cage for best results. Water at the base, not overhead, to prevent blight.
Companion Planting
Plant tomatoes alongside these companions for better growth:
Keep tomatoes away from:
The Bottom Line
Last reviewed: March 29, 2026