Fairplay, CO 80456 planting calendar
- USDA zone
- 5a−20 to −15 °F
- Last frost
- Jun 15avg, 32°F
- First frost
- Sep 9avg, 32°F
- Growing season
- 84days
Fairplay, Colorado is in USDA plant hardiness zone 5a. Its average last spring frost is around June 15 and the first fall frost around September 9, giving a growing season of about 84 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.
Fairplay planting calendar
Each crop's windows are counted from Fairplay'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 | Apr 20 – May 4 | Jun 22 – Jun 29 | Aug 21 – Sep 10 | — |
| Pepper | Very tender | Apr 6 – Apr 20 | Jun 29 – Jul 6 | Aug 28 – Sep 27 | — |
| Cucumber | Tender | May 18 – May 25 | Jun 22 – Jun 29 | Aug 11 – Aug 31 | — |
| Summer squash / zucchini | Tender | — | Jun 22 – Jun 29 | Aug 6 – Aug 21 | — |
| Bush bean | Tender | — | Jun 22 – Jun 29 | Aug 11 – Aug 21 | Jul 11 – Jul 21 |
| Sweet corn | Tender | — | Jun 15 – Jun 29 | Aug 14 – Sep 13 | — |
| Basil | Very tender | May 4 – May 18 | Jun 22 – Jun 29 | Jul 22 – Aug 6 | — |
| Lettuce | Half-hardy | May 4 – May 18 | May 18 – Jun 1 | Jul 2 – Jul 17 | Jun 27 – Jul 12 |
| Pea | Hardy | — | May 4 – May 18 | Jun 28 – Jul 13 | Jun 17 – Jul 2 |
| Spinach | Hardy | — | May 4 – May 18 | Jun 13 – Jun 23 | Jul 7 – Jul 17 |
| Carrot | Half-hardy | — | May 25 – Jun 1 | Jul 24 – Aug 13 | Jun 7 – Jun 27 |
| Broccoli | Half-hardy | Apr 20 – May 4 | May 18 – Jun 1 | Jul 12 – Aug 1 | Jun 12 – Jul 2 |
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 USC00053530. 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 | — | — | — | — | 53 |
| 32°F (freeze) | Jun 15 | Jun 30 | Sep 9 | Sep 22 | 84 |
| 28°F | May 30 | Jun 12 | Sep 22 | Oct 4 | 116 |
| 24°F | May 14 | May 27 | Oct 1 | Oct 16 | 140 |
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) | 746 | standard warm-season base (tomato, corn, beans) |
| Base 40°F (cool-season) | 2,174 | cool-season crops (brassicas, greens) |
Hardiness zone 5a
Fairplay sits in USDA plant hardiness zone 5a on the 2023 map — meaning its average annual extreme minimum winter temperature is about −20 to −15 °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 5a, or see all USDA hardiness zones.
Frequently asked questions
- What USDA hardiness zone is Fairplay?
- Fairplay, Colorado is in USDA plant hardiness zone 5a on the 2023 map (average annual extreme minimum temperature −20 to −15 °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 Fairplay?
- The average (median) last spring frost at 32°F is around June 15, from NOAA's 1991–2020 climate normals at the nearest reporting station. Roughly one year in ten the last frost is as late as June 30, so wait until then before setting out frost-tender plants if you want to be safe.
- When is the first fall frost in Fairplay?
- The average first fall frost at 32°F is around September 9. That leaves a growing season of about 84 days between the average last spring and first fall frosts.
- When should I start tomatoes in Fairplay?
- Start tomato seeds indoors about Apr 20 – May 4 and transplant them outside about Jun 22 – Jun 29, once the danger of frost has passed. Estimated first harvest is around Aug 21 – Sep 10.
- How long is the growing season in Fairplay?
- About 84 days at the 32°F threshold (NOAA 1991–2020, median) — the span between the average last spring frost (~June 15) and the average first fall frost (~September 9). 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 USC00053530 (Grant, 16.7 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.