Zone 1 Planting Guide
Extreme Cold — Alaska Interior & High Mountain Peaks
- Min Winter Temp
- -60 to -50 °F / -51 to -46 °C
- Last Spring Frost
- Late May – mid June
- First Fall Frost
- Late July – mid August
- Growing Season
- 50–80 days
- Annual Rainfall
- 10–20 in
Climate overview
Growing in Zone 1 demands extreme cold-hardiness from every plant you choose. The frost-free window can be as short as 50–60 days, concentrated in June and July. Snow cover often persists from October through May, and permafrost underlies much of the region. Despite these constraints, the long summer days — up to 20+ hours of daylight in Alaska — allow fast-maturing vegetables like radishes, lettuce, and kale to thrive in containers or raised beds with cold frames. Season-extension tools such as row covers, low tunnels, and cold frames are not optional here — they are the difference between a harvest and failure.
States & regions
- Interior Alaska
- High Rockies (above timberline)
Example cities
- Fairbanks, AK
- Tok, AK
- Chicken, AK
Soil notes
Permafrost or shallow, acidic soils common; raised beds with imported soil are standard practice.
- Temperature range
- -60 to -50 °F / -51 to -46 °C
- Growing season
- 50–80 days
- Annual rainfall
- 10–20 inches
Challenges
- Extremely short growing season (50–80 days)
- Permafrost limits in-ground planting
- Late spring and early fall frosts
- Very limited plant palette for perennials
Advantages
- Very long summer daylight hours (18–20+ hrs)
- Low pest and disease pressure due to cold
- Cool nights intensify flavor in root vegetables
Gardening strategies for Zone 1
- 1
Use raised beds filled with imported soil mix to bypass permafrost
- 2
Start all vegetables indoors 6–8 weeks before last frost
- 3
Deploy cold frames and row covers to extend the season by 3–4 weeks
- 4
Focus on fast-maturing varieties (under 60 days to harvest)
- 5
Grow cool-season crops: radishes, lettuce, kale, spinach, turnips
Monthly planting calendar
What to sow, transplant, and harvest each month in Zone 1.
Browse by sun exposure
Find the best plants for your specific spot in Zone 1.
Browse by plant category
Targeted guides for vegetables, herbs, fruits, and flowers in Zone 1.