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Regional Calendars, Climate & DataAlaska Planting Calendar
Alaska has a short growing season, but it has very long summer days. Growers use that daylight, protect crops from cold and match varieties to their own region.
Key points
- Alaska is many climates, so start with local frost data.
- Long daylight speeds growth but can cause bolting in some crops.
- Warm soil with raised beds, plastic and tunnels.
- Use only tested procedures for food preservation.
What sets the Alaska growing season?
Alaska spans coastal rainforest, interior continental climate, and arctic and subarctic areas. Last spring frost, first fall frost and soil warming vary widely among them. The interior has warm summers and cold winters, while southcentral and southeast areas are cooler and wetter in summer.
Because of this variety, advice written for one part of Alaska may not suit another. Begin with your local frost data and ask the University of Alaska Fairbanks Cooperative Extension Service for guidance tied to your region.
Local weather stations and your own thermometer give the best picture. Note soil temperature at planting depth in the morning, because cool soil slows germination even when sunny days feel warm. Garden sites near water or at different elevations can show noticeable differences even within the same community.
How does long daylight help?
In midsummer, daylight extends for many hours, and plants grow quickly during the short season. Some cool-season crops, such as cabbage and root crops, can do very well. Daylight can also affect crops sensitive to day length, such as spinach and lettuce, which may bolt.
Choose varieties suited to northern conditions and compare days to maturity with your frost-free window. Check your state extension planting guide for the range for your area.
- Choose fast varieties
- Watch for bolting under very long days
- Compare days to maturity with your season
How do you warm cold soil?
Soil in Alaska warms slowly and can stay cold well into the season, especially in shaded or low spots. Raised beds, black plastic mulch, clear plastic for early warming, low tunnels and high tunnels all help. Choose a site with good sun exposure and drainage.
Starting transplants indoors and setting them out when the soil has warmed gives long-season crops a head start. Harden transplants off carefully before moving them outside.
What are high tunnels and season extension?
High tunnels, low tunnels and row covers extend both ends of the season. In Alaska, high tunnels can allow crops such as tomatoes and cucumbers that might struggle in open ground. Tunnels need management: vent on warm days, watch humidity and secure the structure against wind and snow load.
Ask your extension office about structure design, snow loads and local building rules. Funding programs for high tunnels exist through USDA NRCS in some places, so check with your local office.
Check the snow load rating of any structure you buy or build, and plan how you will manage heavy snow in fall and spring. Many growers remove or vent plastic coverings seasonally. Your extension office can share designs that have held up in your area.
How do you manage frost, wind and wildlife?
Early and late frosts can occur even in summer in some Alaska locations, so keep cover on hand. Wind dries soil and damages plants, so windbreaks and fences help. Moose, rabbits, voles and birds can damage crops, so plan physical barriers before planting.
For pest and disease problems, identify the cause and ask extension for current recommendations. Pesticide use must follow the label, observe pre-harvest intervals and protect pollinators, and applicator licensing varies by state.
How do you plan harvest and storage?
Short seasons mean harvest timing matters. Count back from your average first fall frost and set a plan for crops that tolerate light frost, such as kale and carrots, and for those that do not. Harvest tender crops before a killing frost and cure or store according to tested guidance.
For canning, freezing, drying and other preservation, use only tested procedures from the National Center for Home Food Preservation, USDA and extension. Do not rely on untested recipes or old family methods without checking.
How do you build your own Alaska calendar?
For example, if your last spring frost usually falls in late May, you might start seeds indoors in the weeks before, set hardy transplants out around that date and tender ones later, and compare the days left before your first fall frost with the days to maturity listed for each variety. This is a worked example of the method and not a recommended date.
Keep a log of soil temperature, last and first frost, planting dates and results. Over the years it will tell you how your own site compares with published averages.
If you grow for sale, check local rules about cottage food, farmers markets and state licensing. Regulations vary by state and municipality, and your extension office or state department of agriculture can point you to the right contact.
Sources and further reading
Last reviewed: November 2026. Educational information, ranges only. Confirm timing with your county extension office.