Peridot, AZ planting calendar
- USDA zone
- 9a20 to 25 °F
- Last frost
- Mar 13avg, 32°F
- First frost
- Nov 19avg, 32°F
- Growing season
- 247days
Peridot, Arizona is in USDA plant hardiness zone 9a. Its average last spring frost is around March 13 and the first fall frost around November 19, giving a growing season of about 247 days (NOAA 1991–2020 normals, 32°F, median). Start tender crops like tomatoes and peppers indoors weeks before the last frost and set them out afterward; sow hardy crops such as peas, spinach, and lettuce before it. The planner below turns those frost dates into a printable per-crop planting calendar.
Peridot planting calendar
Each crop's windows are counted from Peridot's average frost dates. hatched = start seeds indoors, solid green = plant out, teal = a fall sowing, and the terracotta dot marks the estimated first harvest. Ranges are extension-guide planning guidance, not guarantees.
- Start indoors
- Plant out
- Fall sowing
- First harvest
| Crop | Frost tolerance | Start indoors | Plant out | First harvest | Fall planting |
|---|---|---|---|---|---|
| Tomato | Tender | Jan 16 – Jan 30 | Mar 20 – Mar 27 | May 19 – Jun 8 | — |
| Pepper | Very tender | Jan 2 – Jan 16 | Mar 27 – Apr 3 | May 26 – Jun 25 | — |
| Cucumber | Tender | Feb 13 – Feb 20 | Mar 20 – Mar 27 | May 9 – May 29 | — |
| Summer squash / zucchini | Tender | — | Mar 20 – Mar 27 | May 4 – May 19 | — |
| Bush bean | Tender | — | Mar 20 – Mar 27 | May 9 – May 19 | Sep 20 – Sep 30 |
| Sweet corn | Tender | — | Mar 13 – Mar 27 | May 12 – Jun 11 | — |
| Basil | Very tender | Jan 30 – Feb 13 | Mar 20 – Mar 27 | Apr 19 – May 4 | — |
| Lettuce | Half-hardy | Jan 30 – Feb 13 | Feb 13 – Feb 27 | Mar 30 – Apr 14 | Sep 6 – Sep 21 |
| Pea | Hardy | — | Jan 30 – Feb 13 | Mar 26 – Apr 10 | Aug 27 – Sep 11 |
| Spinach | Hardy | — | Jan 30 – Feb 13 | Mar 11 – Mar 21 | Sep 16 – Sep 26 |
| Carrot | Half-hardy | — | Feb 20 – Feb 27 | Apr 21 – May 11 | Aug 17 – Sep 6 |
| Broccoli | Half-hardy | Jan 16 – Jan 30 | Feb 13 – Feb 27 | Apr 9 – Apr 29 | Aug 22 – Sep 11 |
Data: NOAA NCEI U.S. Climate Normals 1991–2020 (public domain) and USDA Plant Hardiness Zone Map 2023. Planting windows synthesized from U.S. Cooperative Extension guides.
Frost & freeze dates
From NOAA's 1991–2020 Climate Normals at station USC00027480. The median (p50) is the average date; the 90%-safe column is the date the freeze has passed in about 9 years out of 10 (p10 for spring, p90 for fall) — the conservative date to plant after or harvest before.
| Threshold | Last spring — avg | Last spring — 90%-safe | First fall — avg | First fall — 90%-safe | Season (days) |
|---|---|---|---|---|---|
| 36°F | Apr 1 | Apr 21 | Nov 9 | Nov 23 | 219 |
| 32°F (freeze) | Mar 13 | Apr 6 | Nov 19 | Dec 4 | 247 |
| 28°F | Feb 17 | Mar 13 | Dec 1 | Dec 18 | 284 |
| 24°F | Jan 25 | Feb 25 | Dec 13 | Jan 14 | 326 |
32°F is the standard "freeze" line that damages tender crops; lighter 36°F frost can nip the most cold-sensitive plants, while hardy crops shrug off light frost down toward 28°F. Use the threshold that matches what you are protecting.
Growing degree days
Growing degree days (GDD) accumulate warmth above a base temperature over the year — a better predictor of crop development than the calendar alone. Warm-season crops need a long, warm GDD total; a short, cool GDD total favors greens and brassicas.
| Model | °F·days | Used for |
|---|---|---|
| Base 50°F (warm-season) | 5,890 | standard warm-season base (tomato, corn, beans) |
| Base 40°F (cool-season) | 9,089 | cool-season crops (brassicas, greens) |
Hardiness zone 9a
Peridot sits in USDA plant hardiness zone 9a on the 2023 map — meaning its average annual extreme minimum winter temperature is about 20 to 25 °F. That number tells you which perennials, shrubs, and trees reliably survive an average winter here; it does not set your planting dates, which come from the frost calendar above.
Explore more places in zone 9a, or see all USDA hardiness zones.
Frequently asked questions
- What USDA hardiness zone is Peridot?
- Peridot, Arizona is in USDA plant hardiness zone 9a on the 2023 map (average annual extreme minimum temperature 20 to 25 °F) — from the USDA Plant Hardiness Zone Map 2023, matched to this location's ZIP. See the methodology page for sources.
- When is the last frost in Peridot?
- The average (median) last spring frost at 32°F is around March 13, from NOAA's 1991–2020 climate normals at the nearest reporting station. Roughly one year in ten the last frost is as late as April 6, so wait until then before setting out frost-tender plants if you want to be safe.
- When is the first fall frost in Peridot?
- The average first fall frost at 32°F is around November 19. That leaves a growing season of about 247 days between the average last spring and first fall frosts.
- When should I start tomatoes in Peridot?
- Start tomato seeds indoors about Jan 16 – Jan 30 and transplant them outside about Mar 20 – Mar 27, once the danger of frost has passed. Estimated first harvest is around May 19 – Jun 8.
- How long is the growing season in Peridot?
- About 247 days at the 32°F threshold (NOAA 1991–2020, median) — the span between the average last spring frost (~March 13) and the average first fall frost (~November 19). Cold-hardy crops extend usable time at both ends; frost-tender crops fit inside it.
Sources & method
Frost, freeze, growing-season, and growing-degree-day figures are NOAA NCEI U.S. Climate Normals 1991–2020 for station USC00027480 (San Carlos Reservoir, 25.5 km away). The hardiness zone is the USDA Plant Hardiness Zone Map 2023, matched to this location's ZIP. Planting windows are computed by counting from the average last and first frost using per-crop offsets synthesized from U.S. Cooperative Extension guides — the full method and citations are on the methodology page.