USDA Zone 1: Where is it? What to Plant? Tips to Success
If you are new to gardening, or new in your area, you may be wondering what to plant this spring.
What you plant and when you plant it depends on where you live, or your hardiness zone.
There are 13 USDA plant hardiness zones across the United States, including Alaska, Hawaii, and Puerto Rico. These zones are determined by temperature, humidity, elevation, and the seasons of that area.
They typically run north to south across the U.S., but there are some areas that don’t quite follow suit. Zone 1 is one such example.
The zone ratings describe where a plant can survive the winter. You can plant trees and flowers outside of your zone, but those plants may not grow or develop like they should. Depending on the growing season, you may get late blooms or plants that bear no fruit.
What is Zone 1?
Zone 1 is one of the thirteen climate zones on the USDA Plant Hardiness Map, which outlines the frost dates and the average regional temperatures.
Each zone is ten degrees warmer or cooler than the zone next to it. The colder the average temperature is, the lower the zone number.
So, zone 1 is the coldest it can get, and in the United States, you find zone 1 only in north and central Alaska.
Zone 1 has an arctic climate with long, frigid winters and very short, cool summers. The temperature can drop 60℉ below zero in the winter, and barely get above freezing (36℉) in the summer.
The plants in zone 1 must be extremely hardy, and be able to survive frigid temperatures and droughts, because there is very little precipitation. The sun does not rise at all during some weeks in the winter, and never sets during some weeks in the summer.
The growing season for zone 1 is short. The last frost hits around June 1st, and the first frost sets in around July 31st. That leaves about two months for outdoor gardening.
Like all 13 zones, zone one consists of two subzones, zone 1a and zone 1b. Zone 1a has average temperatures of -60℉ to -55℉, and zone 1b has average temperatures of -55℉ to -50℉.
Where is Zone 1?
Zone 1 is only in Alaska. Most of zone 1 covers the North Slope of Alaska, which is a barren wasteland. Smaller portions also cover patches of Central Alaska, deep within the national wildlife refuges.
You can find a small strip of zone 1 on the eastern edge of Alaska, as well, by the Tetlin National Wildlife Refuge. There you will find the city of Tok, where the temperatures get as low as 60℉ below zero in the winter months.
Tok lies between the Tanana River and the Alaska Range and is an important junction of the Alaska and Glenn Highways.
Minimum Average Temperatures in Zone 1
Each hardiness zone is divided into two subsets; zone 1 subsets are 1a and 1b. Each subzone is separated by 5 degrees.
- Zone 1: This zone has a minimum average temperature of -60℉ to -50℉.
- Subzone 1a: This subzone has a minimum average temperature of -60℉ to -55℉.
- Subzone 1b: This subzone has a minimum average temperature of -55℉ to -50℉.
The average temperature for the winter months determines the zone and subset ranges. But colder temperatures can occur.
Frost Dates in Zone 1
The frost dates for zone 1 can vary, depending on the current weather patterns.
The average frost dates for zone 1 are:
- Last frost date: around May 22nd June 1st
- First frost date: around August 25th to 31st
The frost dates can also vary based on where you are located in Zone 1 as well. For example, in 2010, Tok last experienced temperatures conducive to frost (32°F or below) on May 18th and on July 29th in 2022.
Zone 1 States
Each state (except Delaware) has multiple hardiness zones because every state’s climate can vary across the state. Portions of Alaska are in zones 1 through 8.
Within the United States, though, zone 1 is only found in Alaska, as is zone 2 after it.
When to Plant in Zone 1
Because zone 1 barely gets above freezing, the growing season is short. That doesn’t mean you can’t plant though.
It’s best to start your seedlings indoors or in a greenhouse and transplant when the temperature warms up. Cold weather crops, such as radishes, lettuce, peas, broccoli, and potatoes will do the best.
Warm season crops, such as tomatoes, peppers, beans, corn, cucumbers, and egg plants need it to warm up a bit before you can transplant them. The nightly temperature should consistently stay above 60℉.
You should wait until the last frost before sowing or transplanting, usually around June 1st.
Tips for Gardening in Zone 1
You can use our interactive hardiness zone map to determine which plants grow best in your region. Believe it or not, there are a lot of plants hardy enough to survive the cooler summers of zone 1.
- Since the growing season is so short, it is best to start your plants indoors, or in a greenhouse, about six weeks before the last frost.
- If you have the resources, you can grow an indoor garden in pots.
- Raised gardens outside are also a great choice, because the ground thaws faster and drains better in a raised bed.
- You can directly sow turnips, strawberries, rutabagas, radish, potatoes, peas, parsnip, onions, mustard, horseradish, carrots, and beets zero to two weeks before the last frost.
- Sow beans zero to two weeks after the last frost.
Check the maturation date on your seed packet. This is the time it takes for your plant to mature and be ready to eat, from sowing to harvesting.
Choosing Plants for Zone 1
Knowing what zone you are in is the first step to choosing your plants.
Next you can research the native plants for zone 1 and talk to the local greenhouses. What do they offer?
You can also check the tag of the plant you purchased or read the seed packet. They should mention the USDA zone.
Keep in mind, the zone listed is the coldest place that the plant can grow, but the zone listing usually applies to perennials. You don’t need your garden vegetables to survive the winter.
You may even be able to plant some warmer zone flowers in your bed and treat them as annuals.
And finally, pay attention to how much water, sun, and soil nutrients you can expect in your area. This will play into what plants you can choose for your garden.
What to Grow in Zone 1
Once you have a good handle on your climate and landscape, it’s time to choose your plants. All is not lost in zone 1!
Below are a few categories and specific varieties that are hardy enough to survive the colder winters and drought-like conditions of this zone:
Trees for Zone 1
There are many zone 1 trees to choose from including fruit trees, flowering trees, evergreens, shrubs, and native trees of Alaska.
Although you can grow a large variety of fruit trees in Alaska, very few are hardy enough to survive the extreme temperatures of zone 1.
- Apple Trees: The Fort Mac Apple and 9-22 End Apple are both good options for zone 1. The September Ruby Apple may be a suitable option if your location is bordering zone 2a. The September Ruby Apple is great for fresh eating, baking, and juicing. Plus, it keeps for up to three months in cold storage. The Fort Mac and 9-22 End Apples are good baking apples, but you must process the 9-22 End Apple pretty quickly, because it does not keep very long. The Fort Mac Apple and the 9-22 End Apple are both self-fertilizing apple trees, meaning you do not need another apple tree for pollination.
- Haskap: The Haskap is also known as the Honeyberry. This shrub’s berries are great for fresh eating, sauces, wines, and baking. They taste like a blueberry.
- Saskatoon Bush: The Saskatoon goes by many names, such as the Western Juneberry, the Prairie Berry, and the Western Service Berry. It produces bluish purple berries in the summer that taste like cherries, but with a hint of almond.
- Other fruit trees: The Hudar Pear and the Crowberry
These flowering trees will add beauty to the harsh, cold landscape all year.
- Netleaf Willow: The Netleaf Willow is an Alaskan native flowering shrub that can survive up to 62℉ below zero. It has simple, broad leaves and spiky, red, purple, and yellow flowers, that bloom in early summer. It is home to many animals and insects, including grassland frogs and tiger flies.
- Dwarf Birch: The Dwarf Birch is a deciduous, low spreading shrub, native to the tundra. It has half-inch leaves that are thick and leathery. The flowers are called catkins, which are thin, spiky flowers, usually with no petals. Each catkin is either male or female, and both sexes can grow on the same plant. These catkins bloom in the spring and are yellowish brown.
- Balsam Poplar: The Balsam Poplar, is a hardy, fast-growing shade tree. It is generally short-lived, although some have been found to be 100 years old. It has sweet, sticky resinous buds and can be used to create cough syrup.
- Other flowering trees: Narrowleaf Cottonwood and the American Linden
Very little evergreens grow in zone 1.
This is because the permafrost is very thin and cannot support an evergreen’s deep roots. The trees that do manage to get their roots past the permafrost usually cannot get them deep enough to keep from being blown over in the harsh tundra winds.
- White Spruce: The White Spruce will grow at the edge of the tundra, bordering other climate zones. It can grow as tall as 120 feet, and it has stiff, pointed needles that are coated in a white wax. They give off a strong odor when crushed. The cones are long and slender. The White Spruce makes an excellent Christmas tree.
- Sub Alpine Fir: The Subalpine Fir goes by many names, such as the balsam fir, the Rocky Mountain fir, and the white fir. It grows up to 100 feet, in the shape of a pyramid. Its needles have blunt edges and are blue-green, with a single white band on the top, and two underneath. The cones are a deep purple. It too, makes a great Christmas tree.
- Crowberry: The Crowberry, also known as the blackberry, is a low-growing, evergreen shrub that makes for a good ground cover. It produces unnoticeable flowers between May and June, and black or purple berries that are great for making wine, juices, or jelly. The fruit can also be used as a natural food dye.
- Quaking Aspen: The Quaking Aspen is a small, beautiful tree that makes a “quaking” sound when the wind blows through its leaves. It grows fast, in the shape of an oval, and can grow as tall as fifty feet. It produces long, silvery catkins in April or May, that give way to cottony tufts in late spring. The leaves turn a brilliant yellow in the fall.
- Other native trees: The Dwarf Birch and the Netleaf Willow
Vegetables for Zone 1
Because vegetables are typically treated as annuals, meaning you only need them to stay alive for the growing season, you can get away with planting vegetables that are not native to zone 1. Cold weather crops do work best in zone 1, however.
- Cabbage: Cabbage cannot survive below 50℉, so you have to pay close attention to the first and last frost dates when planting your cabbage. Plant your cabbage in the ground two weeks after the last frost. If you wait any longer than that, you may not have enough time for the cabbage to mature before the first frost hits. If you are starting your cabbage from seeds, plant them indoors or in a greenhouse 70 days before the average last frost date. As the weather warms up, slowly introduce your cabbage to the outdoors an hour or two at a time, before finally transplanting them after the last frost. This will harden you cabbage and prepare it for outdoor living.
- Kale: Kale is a leafy green vegetable, closely related to cabbage. It cannot survive below 40℉, so again, you need to pay attention to your frost dates. You can plant your kale plants directly into the ground two weeks after the last frost. If you are starting your kale from seeds, plant them indoors or in a greenhouse 50 days before the average last frost date. And slowly introduce your kale to the outdoors to harden the plant before transplanting.
- Potatoes: Potatoes have compound leaves arranged in a spiral. They produce white, lavender, and purple flowers, and a poisonous fruit. The “potato” that we eat grows undergrown, and is the stem of the plant, not the root. You can plant russets, reds, yellows, white, purples, petites, and fingerlings. Potatoes cannot grow in temperatures below 50℉, but you can still directly plant them outdoors. Quarter your seed potatoes and drop one or two into a mound, or plant them in row. Cover them with four to six inches of dirt. You can also start seed potatoes indoors, by planting them in pots 60 days before the last frost date.
- Other vegetables: tomatoes, beans, broccoli, cauliflower, lettuce, radish, spinach, and sweet peas
It is not recommended to plant asparagus in zone 1.
Perennial Flowers for Zone 1
Because zone 1 is mostly a barren wasteland, perennials typically do not grow. You can, however, plant hardy perennials often found in zones 2 and 3 and treat them as annuals.
You may even be able to get them to grow year after year, with a little TLC.
Plant your flowers in sheltered locations, such as between or alongside buildings, or in greenhouses. Cover them with heavy winter mulch during the cold months and give them plenty of water during the warmer months.
If you baby these flowers, you may be able to plant them as perennials:
- Siberian Iris: The Siberian Iris blooms in early spring, with intricate, frilly flowers. The iris makes a gorgeous backdrop for other early bloomers in your flower bed. You plant them by dividing the plants, or by planting corms, which is the underground stem, similar to a bulb. It’s best to plant in late summer or early fall, in full sun to partial shade. The Siberian Iris comes in pink, white, blue, and purple.
- Creeping Jenny: Creeping Jenny is also called Moneywort or Lysimachia. It is an evergreen perennial and works well as cover in hard to grow places. You can plant it in rock gardens, between steppingstones, around ponds, and even in containers. It grows in full sun or shade and has yellow-green foliage that turns bronze in the winter.
- Columbine: Columbine produces bell-shaped flowers in a variety of colors. It blooms in the spring and may be used in cut flower arrangements. The leaves are dark green, turning maroon in the fall. Hummingbirds love Columbine.
- Other perennial flowers: False Spirea, Cranesbill, Delphinium, Lily of the Valley, Golden Rod, Fleabane, Oxeye Daisies, Hosta, Arrowhead, Sunflower, and Lapland Rosebay
At the very least, they will survive the summer. But you may need to replant again next spring.
Herbs for Zone 1
Almost any herb can be grown as an annual in zone 1.
- Yarrow: Yarrow can be planted from a seed or as a plant. They thrive in full sun, and well-drained soil. Yarrow can be invasive, however. Yarrow is used for minor wounds, swollen or cramped muscles, and as a fever reducer. It is also good in shampoos, facial wash, and as an astringent.
- Self-heal: Self-heal is also called Prunella Vulgaris and has been used medicinally for centuries. The entire plant is edible. It can be used both internally and externally, but it is most commonly used for cold sores. It blooms from June through August, with lavender or white flowers. It requires cool to mild temperatures and sun to partial shade. Self-heal can also be invasive, so provide some form of containment.
- Wild Field Mint: Wild Field Mint is not native to zone 1, but it is hardy enough to survive. It grows six to eighteen inches tall, with tufts of flowers puffing out. Plant it in full sun or almost full sun. Wild Field Mint is invasive, and best kept in pots. It is used for flavor and in teas.
- Other herbs: Basil, Chives, Oregano, Rosemary, Thyme, Catnip, Cilantro, Dill, Fennel, and Pennsylvania Cinquefoil
The Zone is Only Part of the Story
The USDA Hardiness Zone Map uses the average lowest temperature of the region, to help you pick the best trees and plants to survive the winter months in your zone. The hardiness zones focus on perennials, which are designed to grow year after year.
You may be able to get by with perennials from other zones, if you treat them as annuals, and are willing to replace them each year.
The map doesn’t take into account other factors, though, such as droughts, rainfall, soil fertility, and unusual weather patterns.
You can start with the USDA Hardiness Zone Map, when choosing your plants, but you also need to know your soil type and the amount of sun you can provide.
Gardening is all about fun and experimentation. So, give some of our recommended plants for Alaska a shot and have fun with it!