When to plant broccoli in Alaska
Alaska’s average last spring frost is May 17, and the first fall frost typically arrives around September 13 — about 119 frost-free days (USDA zones 1a, 2b, 3b, 4b, 5b, 6b, 7b, 8b). Broccoli needs 60–85 days to mature, which fits comfortably within Alaska's growing season.
Alaska covers a wide range of climates, so your exact frost dates may differ from the state average by two weeks or more. For dates tuned to your town, use the calendar generator.
When to plant broccoli in Alaska: the short answer
For a spring planting, plant out Apr 26 – May 13, with seeds started indoors Mar 29 – Apr 12. Seeds germinate in soil from 45 to 85°F.
Windows are ~1–2 week bands around each date. Frost dates are a statewide average from NOAA/NCEI normals; your town may differ by two weeks or more. Calendar year 2026.
How to grow broccoli in Alaska, step by step
- Start seeds indoors (Mar 29 – Apr 12). Sow seeds ½ inch deep in seed-starting mix under bright light. They take 5-10 days to sprout, fastest in soil around 75°F. Harden seedlings off for a week before they go outside.
- Prepare the bed. It needs at least six to eight hours of direct sun a day and loose soil at least 18 inches deep, with a pH between 6.0 and 7.0. Dig in compost before planting.
- Plant out (Apr 26 – May 13). Space plants about 18 inches apart in rows 30 inches apart. It tolerates a light frost but not a hard freeze. As a cool-season crop it does best before summer heat arrives in Alaska.
- Water and feed. Give it steady, even moisture, about an inch of water a week from rain or the hose.
- Watch for pests and problems. Pests: cabbage worm, cabbage looper, aphids, flea beetle, cabbage root maggot. Diseases and disorders: clubroot, black rot, downy mildew.
- Harvest (from about Jul 2 – Jul 27). Broccoli takes 60-85 days to reach harvest. Days to maturity counted from transplant. Keep cutting side shoots after the main head for weeks. Spring crop must size up before heat or it buttons.
Figures come from our crop data; dates use Alaska’s average frost dates. More in the full broccoli growing guide.
Broccoli planting dates by USDA zone in Alaska
Alaska spans USDA zones 1a, 2b, 3b, 4b, 5b, 6b, 7b, 8b. Colder zones, usually higher or further inland, have a later last spring frost and an earlier first fall frost than the state average, so the broccoli dates shift with them.
| Zone | Last frost | First frost | Season | Start indoors | Plant broccoli |
|---|---|---|---|---|---|
| Zone 1 | Jun 15 | Aug 20 | 65 days | Apr 27 – May 11 | May 25 – Jun 11 |
| Zone 2 | Jun 1 | Sep 1 | 90 days | Apr 13 – Apr 27 | May 11 – May 28 |
| Zone 3 | May 15 | Sep 15 | 120 days | Mar 27 – Apr 10 | Apr 24 – May 11 |
| Zone 4 | May 10 | Sep 25 | 135 days | Mar 22 – Apr 5 | Apr 19 – May 6 |
| Zone 5 | Apr 30 | Oct 5 | 160 days | Mar 12 – Mar 26 | Apr 9 – Apr 26 |
| Zone 6 | Apr 15 | Oct 15 | 185 days | Feb 25 – Mar 11 | Mar 25 – Apr 11 |
| Zone 7 | Apr 5 | Oct 25 | 200 days | Feb 15 – Mar 1 | Mar 15 – Apr 1 |
| Zone 8 | Mar 20 | Nov 5 | 230 days | Jan 30 – Feb 13 | Feb 27 – Mar 16 |
When to plant broccoli in nearby states
| State | Last frost | Plant out |
|---|---|---|
| Alaska (this page) | May 17 | Apr 26 – May 13 |
| Hawaii | frost-free | - |
Questions gardeners in Alaska ask
When is the best time to plant broccoli in Alaska?
Plant broccoli transplants outdoors in Alaska between April 26 and May 13. That timing is set by Alaska's average last spring frost of May 17; Alaska spans several climates, so cooler and higher parts of the state run later.
When should I start broccoli seeds indoors in Alaska?
Start seeds indoors between March 29 and April 12, about 6 weeks before the last frost, so the seedlings are ready to plant out from April 26.
Can I plant broccoli in the fall in Alaska?
Yes. For a fall crop, start transplants between June 4 and June 21, so the crop matures in cool weather before Alaska's first frost around September 13.
When will broccoli planted in Alaska be ready to harvest?
Planted on time, broccoli is usually ready from about July 2 to July 27, 60-85 days after transplanting.
When is the last frost in Alaska?
On average around May 17, with the first fall frost around September 13 - about 119 frost-free days. Your town may differ by two weeks or more.