Frost Dates & Planting Calendar for Bethel, AK
Plan your garden around Bethel, AK's typical frost-free growing season, using NOAA climate normals and a 42-crop planting calendar built for this location.
Last Spring Frost
May 21
Safe Jun 2
Typical May 21
Risky May 8
First Fall Frost
September 22
Safe Sep 7
Typical Sep 22
Risky Oct 4
Growing Season
122 days
Typical last frost to typical first frost.
USDA Hardiness Zone
Zone 4a
Very cold winters, focus on short-season varieties and cold-hardy perennials.
Data: NOAA station BETHEL AP, AK US, 4.1 km away.
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days until the typical last spring frost
Monthly Temperatures
Avg. high
Avg. temp
Avg. low
Planting Calendar
| Crop | Start indoors | Direct sow | Transplant | Fall planting | Maturity | Notes |
|---|---|---|---|---|---|---|
| Tomato | Mar 26 – Apr 9 | — | May 28 – Jun 4 | — | 60–85 days | Start indoors 6-8 weeks before last frost; transplant out 1-2 weeks after last frost once soil has warmed. |
| Pepper | Mar 12 – Mar 26 | — | May 28 – Jun 11 | — | 60–90 days | Slow to germinate; start indoors 8-10 weeks before last frost. Transplant only once nights stay above 55F, 1-3 weeks after last frost. |
| Eggplant | Mar 12 – Mar 26 | — | Jun 4 – Jun 11 | — | 65–85 days | Warm-season crop, similar timing to pepper; needs consistently warm soil (65F+) to transplant. |
| Cucumber | Apr 23 – Apr 30 | May 28 – Jun 4 | May 28 – Jun 4 | — | 50–65 days | Can be started indoors 3-4 weeks before transplanting, or direct-sown 1-2 weeks after last frost once soil is warm. |
| Zucchini | Apr 30 – May 7 | May 28 – Jun 11 | May 28 – Jun 4 | — | 45–55 days | Fast-growing squash; direct sow 1-3 weeks after last frost, or start indoors 2-3 weeks early for a head start. |
| Winter Squash | Apr 23 – Apr 30 | May 28 – Jun 11 | May 28 – Jun 4 | — | 80–110 days | Long season; direct sow after soil warms, or start indoors 3-4 weeks before last frost in short-season climates. |
| Pumpkin | — | May 28 – Jun 11 | — | — | 90–120 days | Direct sow 1-3 weeks after last frost; back-time from your first fall frost so the 90-120 day maturity window lands before it. |
| Watermelon | Apr 23 – Apr 30 | — | Jun 4 – Jun 11 | — | 70–90 days | Needs warm soil (65F+); start indoors 3-4 weeks before last frost, transplant 2-3 weeks after last frost. |
| Cantaloupe | Apr 23 – Apr 30 | — | Jun 4 – Jun 11 | — | 70–90 days | Same warm-soil requirements as watermelon; avoid disturbing roots when transplanting. |
| Corn | — | May 21 – Jun 4 | — | — | 60–100 days | Direct sow at last frost to 2 weeks after, once soil reaches 60F; does not transplant well. Succession sow every 2 weeks. |
| Green Bean | — | May 21 – Jun 4 | — | — | 50–65 days | Direct sow at last frost to 2 weeks after, once soil has warmed; frost-tender, do not rush. |
| Pea | — | Apr 9 – Apr 23 | — | — | 55–70 days | Cold-hardy; direct sow 4-6 weeks before last frost as soon as soil can be worked. |
| Lettuce | — | Apr 23 – May 7 | — | Jul 28 – Aug 11 | 45–60 days | Cold-hardy; direct sow 2-4 weeks before last frost. Also transplantable from indoor starts. |
| Spinach | — | Apr 9 – Apr 23 | — | Jul 28 – Aug 11 | 40–50 days | Very cold-hardy; direct sow 4-6 weeks before last frost as soon as soil can be worked. |
| Kale | — | Apr 23 – May 7 | — | Jul 14 – Jul 28 | 50–65 days | Cold-hardy; direct sow 2-4 weeks before last frost or start indoors for earlier transplants. |
| Arugula | — | Apr 23 – May 7 | — | Aug 11 – Aug 18 | 30–40 days | Fast-growing, cold-tolerant green; direct sow 2-4 weeks before last frost, succession sow every 2-3 weeks. |
| Swiss Chard | — | Apr 30 – May 14 | — | — | 50–60 days | Fairly cold-hardy; direct sow 1-3 weeks before last frost. Tolerates light frost in fall too. |
| Broccoli | Apr 2 – Apr 16 | — | Apr 30 – May 7 | Jul 21 – Jul 28 | 55–80 days | Start indoors 5-7 weeks before last frost; transplant out 2-3 weeks before last frost (hardens off to light frost). |
| Cauliflower | Apr 2 – Apr 16 | — | May 7 – May 14 | Jul 14 – Jul 21 | 55–85 days | Fussier than broccoli about temperature swings; start indoors 5-7 weeks before last frost, transplant 1-2 weeks before last frost. |
| Cabbage | Apr 2 – Apr 16 | — | Apr 23 – May 7 | Jul 14 – Jul 28 | 60–100 days | Cold-hardy; start indoors 5-7 weeks before last frost, transplant 2-4 weeks before last frost. |
| Brussels Sprouts | Apr 2 – Apr 16 | — | Apr 30 – May 14 | — | 90–110 days | Long-season crop best timed to mature after a light fall frost for sweetest flavor; start indoors 5-7 weeks before last frost. |
| Carrot | — | Apr 23 – May 7 | — | Jun 30 – Jul 14 | 60–80 days | Direct sow only (does not transplant); sow 2-4 weeks before last frost, as soon as soil can be worked. |
| Beet | — | Apr 23 – May 7 | — | Jul 14 – Jul 28 | 50–65 days | Direct sow 2-4 weeks before last frost; tolerates light frost. |
| Radish | — | Apr 16 – Apr 30 | — | Aug 11 – Aug 25 | 22–30 days | Very fast and cold-hardy; direct sow 3-5 weeks before last frost, as soon as soil can be worked. |
| Turnip | — | Apr 23 – May 7 | — | Jul 14 – Jul 28 | 40–60 days | Cold-hardy; direct sow 2-4 weeks before last frost. |
| Onion | Mar 12 – Mar 26 | — | Apr 23 – May 7 | — | 90–120 days | Start seeds indoors 8-10 weeks before last frost (or use sets/transplants); set out 2-4 weeks before last frost, very cold-tolerant as seedlings. |
| Garlic | — | — | — | Aug 25 – Sep 8 | 240–270 days | Fall-planted crop only; not planted in spring in most climates. |
| Potato | — | Apr 23 – May 7 | — | — | 70–120 days | Plant seed potatoes 2-4 weeks before last frost, as soon as soil can be worked and is above 45F; light frost on emerging foliage is usually tolerated. |
| Sweet Potato | — | — | Jun 4 – Jun 18 | — | 90–120 days | Set out slips 2-4 weeks after last frost once soil is thoroughly warm (65F+); very frost/cold sensitive. |
| Asparagus | — | — | Apr 23 – May 7 | — | 730–1095 days | Perennial; plant crowns 2-4 weeks before last frost as soon as soil can be worked. Takes 2-3 years to full production. |
| Crop | Start indoors | Direct sow | Transplant | Fall planting | Maturity | Notes |
|---|---|---|---|---|---|---|
| Basil | Apr 9 – Apr 16 | — | May 28 – Jun 4 | — | 50–70 days | Very frost/cold sensitive; start indoors 5-6 weeks before last frost, transplant only after all danger of frost (1-2 weeks after) and nights stay warm. |
| Cilantro | — | Apr 30 – May 14 | — | Jul 28 – Aug 11 | 45–70 days | Cool-season, bolts in heat; direct sow 1-3 weeks before last frost, succession sow through spring. |
| Parsley | Mar 26 – Apr 9 | — | May 7 – May 14 | — | 70–90 days | Slow to germinate; start indoors 6-8 weeks before last frost, transplant 1-2 weeks before last frost (biennial, cold-tolerant). |
| Dill | — | Apr 30 – May 14 | — | — | 40–60 days | Taprooted, does not transplant well; direct sow 1-3 weeks before last frost, succession sow through summer. |
| Oregano | Mar 26 – Apr 9 | — | May 21 – May 28 | — | 80–90 days | Perennial herb; start indoors 6-8 weeks before last frost, transplant around/just after last frost date. |
| Thyme | Mar 26 – Apr 9 | — | May 21 – May 28 | — | 85–95 days | Perennial herb, slow from seed; start indoors 6-8 weeks before last frost, transplant around/after last frost. |
| Crop | Start indoors | Direct sow | Transplant | Fall planting | Maturity | Notes |
|---|---|---|---|---|---|---|
| Sunflower | — | May 28 – Jun 11 | — | — | 70–100 days | Direct sow 1-3 weeks after last frost once soil has warmed; taprooted, resents transplanting. |
| Zinnia | Apr 23 – Apr 30 | May 28 – Jun 11 | May 28 – Jun 4 | — | 60–70 days | Frost-tender; direct sow 1-3 weeks after last frost, or start indoors 3-4 weeks early for earlier blooms. |
| Marigold | Apr 9 – Apr 23 | — | May 28 – Jun 4 | — | 45–60 days | Frost-tender; start indoors 4-6 weeks before last frost, transplant after all frost danger has passed. |
| Cosmos | Apr 23 – Apr 30 | May 28 – Jun 11 | May 28 – Jun 4 | — | 60–90 days | Easy from direct seed 1-3 weeks after last frost; can also start indoors 3-4 weeks early. |
| Nasturtium | — | May 28 – Jun 11 | — | — | 50–65 days | Frost-tender, resents root disturbance; direct sow 1-3 weeks after last frost once soil has warmed. |
| Dahlia | — | — | May 28 – Jun 11 | — | 90–120 days | Plant tubers 1-3 weeks after last frost once soil is warm (60F+); very frost-sensitive. |
Date ranges are estimates based on university extension guidelines and this city's NOAA frost normals — not a guarantee. Scroll to see all columns on narrow screens.
Frequently Asked Questions
When is the last frost in Bethel, AK?
Based on 1991–2020 NOAA climate normals for the BETHEL AP, AK US station, the last spring frost in Bethel typically falls around May 21. A cautious gardener might wait until June 2 (only a 10% chance of a later frost), while May 8 marks an earlier, higher-risk planting date.
When is the first frost in Bethel, AK in fall?
The first fall frost in Bethel typically arrives around September 22. To stay safe, assume frost could start as early as September 7; in milder years it can hold off until October 4.
How long is the growing season in Bethel, AK?
Bethel's average frost-free growing season is about 122 days, running from the typical last spring frost (May 21) to the typical first fall frost (September 22).
What USDA hardiness zone is Bethel, AK in?
Bethel, AK is in USDA plant hardiness zone 4a, per the USDA's 2023 Plant Hardiness Zone Map. Very cold winters, focus on short-season varieties and cold-hardy perennials.