What to plant in August in Alaska
In Alaska (AK), August sits about 4 weeks before the average first fall frost (September 13). The state averages 119 frost-free days a year (last frost May 17, first frost September 13; USDA zones 1a, 2b, 3b, 4b, 5b, 6b, 7b, 8b).
8 crops have a sowing or planting window this month, including chervil, mustard greens, spinach, tatsoi, turnip, arugula - and 8 of those windows close during August.
Dates here come from Alaska frost dates (last frost May 17, first frost Sep 13). For one crop in detail, see when to plant spinach, arugula or radish in Alaska.
Alaska covers a very wide range of climates, so dates near you can be two weeks or more either side of these. Enter your ZIP code in the planting calendar for dates tuned to your town.
Alaska: planting activity through the year
Last chance in August
Chervil (sow for a fall crop, by Aug 2) · Mustard Greens (sow for a fall crop, by Aug 2) · Spinach (sow for a fall crop, by Aug 2) · Tatsoi (sow for a fall crop, by Aug 2) · Turnip (sow for a fall crop, by Aug 2) · Arugula (sow for a fall crop, by Aug 9) · Watercress (sow for a fall crop, by Aug 9) · Radish (sow for a fall crop, by Aug 16)
For fall and winter harvests (8)
Sowings counted back from Alaska's first fall frost, so the crop matures before the cold - or, for garlic and similar, planted after it.
| Crop | What to do | Window | This month |
|---|---|---|---|
| Chervil | Sow for a fall crop | Jul 16 – Aug 2 | Last chance - ends Aug 2 |
| Mustard Greens | Sow for a fall crop | Jul 16 – Aug 2 | Last chance - ends Aug 2 |
| Spinach | Sow for a fall crop | Jul 16 – Aug 2 | Last chance - ends Aug 2 |
| Tatsoi | Sow for a fall crop | Jul 16 – Aug 2 | Last chance - ends Aug 2 |
| Turnip | Sow for a fall crop | Jul 16 – Aug 2 | Last chance - ends Aug 2 |
| Arugula | Sow for a fall crop | Jul 23 – Aug 9 | Last chance - ends Aug 9 |
| Watercress | Sow for a fall crop | Jul 23 – Aug 9 | Last chance - ends Aug 9 |
| Radish | Sow for a fall crop | Jul 30 – Aug 16 | Last chance - ends Aug 16 |
Harvesting in August
First harvests expected this month from crops sown or planted on time earlier in the season.
Planting dates for popular crops in Alaska
Every crop has its own full-year dates for Alaska: indoor start, transplant or direct sowing, and harvest.
Fall garden season: August garden jobs in Alaska
- The average first frost is September 13, about 4 weeks away. Pick tender crops (tomatoes, peppers, squash, beans) before it, or cover them on cold nights.
- Still time to sow or plant: chervil, mustard greens, spinach, tatsoi, turnip, arugula. Fast greens and radishes are the safest bets this late.
- Row cover buys 4-6°F of frost protection and weeks of extra harvest - see season extension.
- Pull finished crops and sow a cover crop (cereal rye or crimson clover) into empty beds before the soil gets cold.
USDA zone chart for 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.
Questions gardeners ask
What vegetables can I plant in Alaska in August?
8 crops have a window in August: chervil, mustard greens, spinach, tatsoi, turnip, arugula, watercress, radish. The tables above give the exact dates for each.
Is it too late to plant garlic in Alaska in August?
Not too late - it's actually a little early. In Alaska the next garlic window opens around September 24: plant in fall, after first frost.
Is it too late to plant tomatoes in Alaska in August?
For this year, yes - the tomato windows in Alaska have closed. The next step is to start seeds indoors from about March 22.
When is the first frost in Alaska?
The statewide average first fall frost is around September 13 and the last spring frost around May 17. Alaska covers a wide range of climates, so local dates can differ by two weeks or more - look yours up by ZIP code.
What can I harvest in Alaska in August?
From plantings made on time: cabbage, cauliflower, radicchio, tarragon, potato, parsley, new zealand spinach, fennel (bulb), summer savory, mint.
What to plant in August in other states
Dates are computed from Alaska’s statewide average frost dates (from NOAA/NCEI climate normals) and each crop’s timing in our crop database. Your garden may be a week or two either side - for dates tuned to your ZIP code, use the planting calendar.