Maricopa, AZ planting zone & frost dates
Maricopa is in USDA hardiness zone 9a. The last spring frost usually comes around February 23 and the first fall frost around November 24, for a growing season of about 274 days.
Planting calendar for Maricopa
Dates are counted from the average last spring frost (February 23) using the typical timing recommended by U.S. extension services. Warm-season crops go out only after the danger of frost has passed and the soil has warmed.
| Crop | When |
|---|---|
| Tomatoes | Start seeds indoors: Dec 29 – Jan 12 Transplant outdoors: Mar 2 – Mar 9 |
| Peppers | Start seeds indoors: Dec 15 – Dec 29 Transplant outdoors: Mar 9 – Mar 16 |
| Eggplant | Start seeds indoors: Dec 15 – Dec 29 Transplant outdoors: Mar 9 – Mar 16 |
| Broccoli | Start seeds indoors: Dec 15 – Dec 29 Transplant outdoors: Jan 26 – Feb 9 |
| Cabbage | Start seeds indoors: Dec 15 – Dec 29 Transplant outdoors: Jan 26 – Feb 9 |
| Onions (sets) | Plant outdoors: Jan 26 – Feb 9 |
| Peas | Sow outdoors: Jan 12 – Jan 26 |
| Spinach | Sow outdoors: Jan 12 – Jan 26 |
| Lettuce | Sow outdoors: Jan 26 – Feb 9 |
| Carrots | Sow outdoors: Jan 26 – Feb 9 |
| Potatoes | Plant outdoors: Jan 26 – Feb 9 |
| Beans | Sow outdoors: Mar 2 – Mar 9 |
| Sweet corn | Sow outdoors: Mar 2 – Mar 9 |
| Cucumbers | Sow outdoors: Mar 2 – Mar 9 |
| Squash & zucchini | Sow outdoors: Mar 2 – Mar 9 |
| Basil | Start seeds indoors: Jan 12 – Jan 26 Transplant outdoors: Mar 2 – Mar 9 |
Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Sep 29 (8 weeks before the average first fall frost on Nov 24).
Useful for zone 9a gardens
- Seed starting kit with dome — to start seeds indoors before the last frost
- LED grow light for seedlings — stops leggy seedlings
- Frost cloth / plant covers — for late spring and early fall frosts
- Soil thermometer — warm-season crops need soil above 60°F
- Shade cloth — for hot summers
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Frost risk in detail
| 90% chance | 50% chance | 10% chance | |
|---|---|---|---|
| Last 32°F frost in spring is after | Jan 29 | Feb 23 | Mar 15 |
| First 32°F frost in fall is before | Dec 8 | Nov 24 | Nov 10 |
How to read it: in spring there is a 10% chance of a frost after March 15, so that is a safe date for tender plants. In fall there is a 10% chance of frost before November 10. A hard freeze (28°F) usually ends around February 2.
Hardiness zone by ZIP code in Maricopa
- 85138 zone 9a
- 85139 zone 9a
Nearby cities
- Sun Lakes zone 9b, last frost Feb 1
- Chandler zone 9b, last frost Feb 13
- Casa Grande zone 9a, last frost Feb 5
- Tempe Junction zone 9b, last frost Feb 13
- Tempe zone 10a, last frost Feb 13
- Phoenix zone 10a
- Gilbert zone 9b, last frost Feb 13
- Mesa zone 9b, last frost Feb 13
Questions
What growing zone is Maricopa, AZ?
Maricopa is in USDA Plant Hardiness Zone 9a (average extreme winter low 20°F to 25°F), according to the USDA 2023 map.
When is the last frost in Maricopa?
The average last spring frost (32°F) in Maricopa is February 23. There is still a 10% chance of frost until March 15.
When can I plant tomatoes in Maricopa?
Transplant tomatoes outdoors 1–2 weeks after the average last frost: around Mar 2 – Mar 9. Start seeds indoors 6–8 weeks before the last frost.
Frost dates: NOAA U.S. Climate Normals 1991–2020, station Maricopa 4 N, AZ (USC00025270), 6.4 km (4.0 mi) from the city center, elevation 354 m, based on 22 years of records. Hardiness zone: USDA Plant Hardiness Zone Map 2023 for the ZIP code nearest to the city center. Microclimates (valleys, hills, cities, coasts) can be warmer or colder: check the local forecast before planting. How we calculate the data.