Healy Lake, AK planting calendar
- USDA zone
- 3b−35 to −30 °F
- Last frost
- Jun 5avg, 32°F
- First frost
- Aug 21avg, 32°F
- Growing season
- 75days
Healy Lake, Alaska is in USDA plant hardiness zone 3b. Its average last spring frost is around June 5 and the first fall frost around August 21, giving a growing season of about 75 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.
Healy Lake planting calendar
Each crop's windows are counted from Healy Lake'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 10 – Apr 24 | Jun 12 – Jun 19 | Aug 11 – Aug 31 | — |
| Pepper | Very tender | Mar 27 – Apr 10 | Jun 19 – Jun 26 | Aug 18 – Sep 17 | — |
| Cucumber | Tender | May 8 – May 15 | Jun 12 – Jun 19 | Aug 1 – Aug 21 | — |
| Summer squash / zucchini | Tender | — | Jun 12 – Jun 19 | Jul 27 – Aug 11 | — |
| Bush bean | Tender | — | Jun 12 – Jun 19 | Aug 1 – Aug 11 | Jun 22 – Jul 2 |
| Sweet corn | Tender | — | Jun 5 – Jun 19 | Aug 4 – Sep 3 | — |
| Basil | Very tender | Apr 24 – May 8 | Jun 12 – Jun 19 | Jul 12 – Jul 27 | — |
| Lettuce | Half-hardy | Apr 24 – May 8 | May 8 – May 22 | Jun 22 – Jul 7 | Jun 8 – Jun 23 |
| Pea | Hardy | — | Apr 24 – May 8 | Jun 18 – Jul 3 | May 29 – Jun 13 |
| Spinach | Hardy | — | Apr 24 – May 8 | Jun 3 – Jun 13 | Jun 18 – Jun 28 |
| Carrot | Half-hardy | — | May 15 – May 22 | Jul 14 – Aug 3 | May 19 – Jun 8 |
| Broccoli | Half-hardy | Apr 10 – Apr 24 | May 8 – May 22 | Jul 2 – Jul 22 | May 24 – Jun 13 |
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 USC00502352. 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 | — | — | — | — | 48 |
| 32°F (freeze) | Jun 5 | Jun 30 | Aug 21 | Sep 1 | 75 |
| 28°F | May 25 | Jun 5 | Sep 1 | Sep 14 | 99 |
| 24°F | May 12 | May 28 | Sep 14 | Sep 26 | 123 |
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) | 657 | standard warm-season base (tomato, corn, beans) |
| Base 40°F (cool-season) | 1,844 | cool-season crops (brassicas, greens) |
Hardiness zone 3b
Healy Lake sits in USDA plant hardiness zone 3b on the 2023 map — meaning its average annual extreme minimum winter temperature is about −35 to −30 °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 3b, or see all USDA hardiness zones.
Frequently asked questions
- What USDA hardiness zone is Healy Lake?
- Healy Lake, Alaska is in USDA plant hardiness zone 3b on the 2023 map (average annual extreme minimum temperature −35 to −30 °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 Healy Lake?
- The average (median) last spring frost at 32°F is around June 5, 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 Healy Lake?
- The average first fall frost at 32°F is around August 21. That leaves a growing season of about 75 days between the average last spring and first fall frosts.
- When should I start tomatoes in Healy Lake?
- Start tomato seeds indoors about Apr 10 – Apr 24 and transplant them outside about Jun 12 – Jun 19, once the danger of frost has passed. Estimated first harvest is around Aug 11 – Aug 31.
- How long is the growing season in Healy Lake?
- About 75 days at the 32°F threshold (NOAA 1991–2020, median) — the span between the average last spring frost (~June 5) and the average first fall frost (~August 21). 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 USC00502352 (Delta Junction 20 Se, 21.2 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.