
Introduction
Alaska is the biggest state in the United States, with a very unique and varied climate. Conditions are at times quite severe on gardening and agriculture. With this in mind, the USDA has come up with a well-rounded Plant Hardiness Zone Map to assist gardeners and farmers in their planting decisions. This very extremely serves as a very important tool in understanding the growing zones within Alaska and allows each resident the opportunity to pick the right plants that can grow in their zone.
What is the USDA Plant Hardiness Zone Map?
The USDA Plant Hardiness Zone Map is used as the standard through which a gardener or grower can refer to find out plants that are more likely to thrive at a location. The map takes into consideration an average annual extreme minimum temperature, divided by 10-degree Fahrenheit zones. Each zone represents a range of temperatures a plant is able to bear. The zones are numbered from 1, the coldest, to 13, the warmest.
Unique Alaska Climate and Its Challenges
Alaska’s climate is quite variable due to the state’s large area and geography. The state ranges from very cold in the interior to maritime influences along the coast and relatively milder conditions in the south-central regions. This broad span of climatic conditions further breaks up this great state into distinctly different planting zones, each represented by a different set of challenges and opportunities for gardeners intending to plant there.
Alaska USDA Planting Zones Overview
The USDA Plant Hardiness Zone Map for Alaska contains zones 1 through 7, which indicates the wide temperature range of the state. The following is an overview of each zone.
1. Zone 1: (-60°F to -50°F)
Locations: Northernmost parts of Alaska, including parts of the Arctic Coastal Plain and the Brooks Range.
Challenges: Extreme cold, short growing seasons, permafrost
Type of Plants: Hardy perennials, some native plants, cold-resistant vegetables
2. Zone 2: (-50°F to -40°F)
Areas—Northern and central interior regions; vicinity of Barrow and Fairbanks.
Challenges: Extreme cold, very short growing season, poor soils.
Suitable Plants: Cold-hardy shrubs, evergreens, some vegetables such as carrots and radishes .
3. Zone 3 (-40°F to -30°F)
Locations—Interior regions, parts of Yukon River Valley.
Challenges: Extreme cold, soil drainage.
Suitable Plants: Cold-hardy trees like birch and spruce, vegetables like peas and lettuce.
4. Zone 4 (-30°F to -20°F)
Locations: Areas around Anchorage, the Matanuska-Susitna Valley, and parts of the Kenai Peninsula.
Challenges: Cold winters and moderate growing seasons.
Suitable Plants: A wide variety of trees, shrubs, and perennials; most vegetables and many fruits, including potatoes and strawberries.
5. Zone 5 (-20°F to -10°F)
Locations: South-central Alaska, including Juneau and the northern Panhandle.
Challenges: Milder winters but still a short growing season.
Most fruit trees and berries; tomatoes and all vegetables except those requiring a very long growing season.
6. Zone 6 (-10°F to 0°F)
Locations: Southern coastal belt, including the Panhandle and Sitka areas.
Challenges: Long growing season, high humidity and heavy rainfall.
Plants Suitable for Zone: Most vegetables, fruits and most ornamental plants.
7. Zone 7 (0°F to 10°F)
Locations: Extreme southernmost coastal belt, including Ketchikan and parts of Panhandle.
Challenges: Very wet, very mild winters.
Shrubs: A wide range of garden plants; most, including more tender kinds which cannot stand colder areas.
Gardening Tips for Each Zone
Understanding challenges and opportunities specific to each zone can better prepare a gardener to take advantage of the growing conditions. Some general tips for gardening in each of Alaska’s USDA zones include the following:
Zone 1 & 2:
Use cold frames and greenhouses to extend the growing season.
Use plants that are native or known to be very cold hardy. Make the soil drain well and more fertile.
Zone 3 & 4:
Start seeds indoors to get a head start on the very short growing season.
Use heavy mulching to protect plants from cold snaps.
Grow early-maturation varieties of vegetables.
Zone 5 & 6:
Build raised beds that will warm up fast and drain well.
Use companion planting to fill in places and enhance yields.
Use row covers to protect plants from unexpected cold spells.
Zone 7:
Make use of the milder climate that gives increased production of crops for wider varieties.
Improve the drainage to prevent root rot from too much moisture. Make use of vertical gardening in enhancing limited space.
Conclusion
The USDA Plant Hardiness Zone Map is such a great tool for Alaskan gardeners since it offers them the vital information regarding the best plants that should grow in each region’s special climate. Knowing the planting zone, gardeners can help themselves out with plants that have a better chance of success in the different regions, therefore having more successful and rewarding gardening experiences. From the interior’s frigid to the more mild coastal areas, there are ample opportunities for growing a wide array of plants and enjoying all that an Alaskan garden has to offer in beauty and bounty.