Grayling, AK planting calendar
- USDA zone
- 3a−40 to −35 °F
- Last frost
- May 25avg, 32°F
- First frost
- Sep 3avg, 32°F
- Growing season
- 101days
Grayling, Alaska is in USDA plant hardiness zone 3a. Its average last spring frost is around May 25 and the first fall frost around September 3, giving a growing season of about 101 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.
Grayling planting calendar
Each crop's windows are counted from Grayling'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 | Mar 30 – Apr 13 | Jun 1 – Jun 8 | Jul 31 – Aug 20 | — |
| Pepper | Very tender | Mar 16 – Mar 30 | Jun 8 – Jun 15 | Aug 7 – Sep 6 | — |
| Cucumber | Tender | Apr 27 – May 4 | Jun 1 – Jun 8 | Jul 21 – Aug 10 | — |
| Summer squash / zucchini | Tender | — | Jun 1 – Jun 8 | Jul 16 – Jul 31 | — |
| Bush bean | Tender | — | Jun 1 – Jun 8 | Jul 21 – Jul 31 | Jul 5 – Jul 15 |
| Sweet corn | Tender | — | May 25 – Jun 8 | Jul 24 – Aug 23 | — |
| Basil | Very tender | Apr 13 – Apr 27 | Jun 1 – Jun 8 | Jul 1 – Jul 16 | — |
| Lettuce | Half-hardy | Apr 13 – Apr 27 | Apr 27 – May 11 | Jun 11 – Jun 26 | Jun 21 – Jul 6 |
| Pea | Hardy | — | Apr 13 – Apr 27 | Jun 7 – Jun 22 | Jun 11 – Jun 26 |
| Spinach | Hardy | — | Apr 13 – Apr 27 | May 23 – Jun 2 | Jul 1 – Jul 11 |
| Carrot | Half-hardy | — | May 4 – May 11 | Jul 3 – Jul 23 | Jun 1 – Jun 21 |
| Broccoli | Half-hardy | Mar 30 – Apr 13 | Apr 27 – May 11 | Jun 21 – Jul 11 | Jun 6 – Jun 26 |
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 USW00026502. 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 | — | — | — | — | 73 |
| 32°F (freeze) | May 25 | Jun 11 | Sep 3 | Sep 21 | 101 |
| 28°F | May 12 | May 29 | Sep 17 | Oct 2 | 125 |
| 24°F | May 5 | May 19 | Sep 26 | Oct 11 | 144 |
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) | 747 | standard warm-season base (tomato, corn, beans) |
| Base 40°F (cool-season) | 1,964 | cool-season crops (brassicas, greens) |
Hardiness zone 3a
Grayling sits in USDA plant hardiness zone 3a on the 2023 map — meaning its average annual extreme minimum winter temperature is about −40 to −35 °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 3a, or see all USDA hardiness zones.
Frequently asked questions
- What USDA hardiness zone is Grayling?
- Grayling, Alaska is in USDA plant hardiness zone 3a on the 2023 map (average annual extreme minimum temperature −40 to −35 °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 Grayling?
- The average (median) last spring frost at 32°F is around May 25, 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 11, so wait until then before setting out frost-tender plants if you want to be safe.
- When is the first fall frost in Grayling?
- The average first fall frost at 32°F is around September 3. That leaves a growing season of about 101 days between the average last spring and first fall frosts.
- When should I start tomatoes in Grayling?
- Start tomato seeds indoors about Mar 30 – Apr 13 and transplant them outside about Jun 1 – Jun 8, once the danger of frost has passed. Estimated first harvest is around Jul 31 – Aug 20.
- How long is the growing season in Grayling?
- About 101 days at the 32°F threshold (NOAA 1991–2020, median) — the span between the average last spring frost (~May 25) and the average first fall frost (~September 3). 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 USW00026502 (Kaltag Ap, 172.9 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.