New River, AZ planting zone & frost dates
New River is in USDA hardiness zone 9b. The last spring frost usually comes around January 15 and the first fall frost around December 22, for a growing season of about 341 days.
Planting calendar for New River
Dates are counted from the average last spring frost (January 15) 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: Nov 20 – Dec 4 Transplant outdoors: Jan 22 – Jan 29 |
| Peppers | Start seeds indoors: Nov 6 – Nov 20 Transplant outdoors: Jan 29 – Feb 5 |
| Eggplant | Start seeds indoors: Nov 6 – Nov 20 Transplant outdoors: Jan 29 – Feb 5 |
| Broccoli | Start seeds indoors: Nov 6 – Nov 20 Transplant outdoors: Dec 18 – Jan 1 |
| Cabbage | Start seeds indoors: Nov 6 – Nov 20 Transplant outdoors: Dec 18 – Jan 1 |
| Onions (sets) | Plant outdoors: Dec 18 – Jan 1 |
| Peas | Sow outdoors: Dec 4 – Dec 18 |
| Spinach | Sow outdoors: Dec 4 – Dec 18 |
| Lettuce | Sow outdoors: Dec 18 – Jan 1 |
| Carrots | Sow outdoors: Dec 18 – Jan 1 |
| Potatoes | Plant outdoors: Dec 18 – Jan 1 |
| Beans | Sow outdoors: Jan 22 – Jan 29 |
| Sweet corn | Sow outdoors: Jan 22 – Jan 29 |
| Cucumbers | Sow outdoors: Jan 22 – Jan 29 |
| Squash & zucchini | Sow outdoors: Jan 22 – Jan 29 |
| Basil | Start seeds indoors: Dec 4 – Dec 18 Transplant outdoors: Jan 22 – Jan 29 |
Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Oct 27 (8 weeks before the average first fall frost on Dec 22).
Useful for zone 9b 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 | Dec 19 | Jan 15 | Feb 21 |
| First 32°F frost in fall is before | Jan 26 | Dec 22 | Nov 29 |
How to read it: in spring there is a 10% chance of a frost after February 21, so that is a safe date for tender plants. In fall there is a 10% chance of frost before November 29. A hard freeze (28°F) usually ends around January 9.
Hardiness zone by ZIP code in New River
- 85087 zone 9b
Nearby cities
- Sun City West zone 9b, last frost Jan 20
- Sun City zone 9b, last frost Jan 20
- Surprise zone 9b, last frost Jan 20
- Peoria zone 9b, last frost Jan 20
- El Mirage zone 9b, last frost Jan 20
- Glendale zone 9b, last frost Jan 20
- Paradise Valley zone 10a, last frost Jan 6
- Scottsdale zone 10a, last frost Feb 13
Questions
What growing zone is New River, AZ?
New River is in USDA Plant Hardiness Zone 9b (average extreme winter low 25°F to 30°F), according to the USDA 2023 map.
When is the last frost in New River?
The average last spring frost (32°F) in New River is January 15. There is still a 10% chance of frost until February 21.
When can I plant tomatoes in New River?
Transplant tomatoes outdoors 1–2 weeks after the average last frost: around Jan 22 – Jan 29. Start seeds indoors 6–8 weeks before the last frost.
Frost dates: NOAA U.S. Climate Normals 1991–2020, station Castle Hot Springs, AZ (USC00021353), 22.2 km (13.8 mi) from the city center, elevation 607 m, based on 28 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.