They’re important because — with hardiness ratings tied to individual plant varieties and indicated on plant tags and on websites — it’s easy to know which plants will survive the winter in your area.
In Zone 4, early snowmelt in the spring and additional frost-free days in the fall allow a wide variety of foods to flourish.
There are also more evergreen shrubs to choose from, more annual flowers that have the frost-free growing season they need, and different types of perennials play a role. We examine the main features of gardening in this region, and consider which plants will thrive best in this climate.
How to Garden in US Hardiness Zone 4
In Zone 4, average winter lows fall in the range of -30 F and -20 F. It is important to remember that whether a particular plant grows in your garden or not is also affected by the local presence of mountains, large bodies of water and buildings.
Gardening in Zone 4
- Choose plants labeled as suitable for Zone 4, but don’t be too strict about applying this rule. Some plants classified as zone 5 may succeed in suitable garden climates.
- Hoop houses and low tunnels are especially valuable in helping steal extra growing days in the spring.
- Spring mulching will have a beneficial insulating effect in the fall.
- Evergreen shrubs and small, mature trees help create microclimates and comfortable places where border plants can thrive.
- Remember that features in neighbors’ gardens and in your own gardens can also create protected areas.
- But fences, walls and hedges can also protect plantings from the warmth of the spring sun and hinder spring growth.
- Don’t be afraid to expect the unexpected: Carefully selected kiwi vines and cacti can thrive in Zone 4.
- Mulch is your friend – bark, garden compost, compost leaves and gravel (in sunny, well-drained areas) all help ease winter chills, while black plastic helps raise soil temperatures in the spring.
- Consider creating raised beds, as in the spring they will warm up more quickly than other areas (and will also reduce back pain from weeding).
Zone 4 – Key Features
Average cold winter temperatures in Zone 4 fall to between -30 F and -20 F.
Zone 4a has a minimum average temperature of -30 F to -25 F. Zone 4b has a minimum average temperature of -25 F to -20 F.
Region 4 includes much of the northernmost part of the United States including most of Montana, parts of western and southern Alaska, and most of North Dakota, Minnesota, and highland Wyoming. It also includes parts of South Dakota, Wisconsin, New York, Vermont, New Hampshire, and Maine.
The ground in Zone 4 remains frozen and hard for several winter months, plants remain dormant, and the active growing season is usually about four months. The long summer days are often warm.
The first frost date in the fall is usually around September 21 – October 7, while the last frost date in the spring is usually around April 24 – May 12.
Zone 4 plants
Many deciduous trees, shrubs, perennials, vegetables and fruits enjoy Zone 4 and many annuals, especially fast-growing species, will thrive in the longer, warmer days of summer.
flowering cherry (Plum) Clouds of white or pink spring flowers, some with a fiery autumn color or attractive bark.
Magnolia bowl (Magnolia x solangiana) A stunning spring display of large pink or white saucer-like flowers.
Also try: Crabapple (Malos)
Colorado spruce (Picaea bongens) A vigorous, elegant tree with cultivars in a range of heights, many with silvery-blue needles.
Tree of the life (Thuja western) is native to North America in a wide range of cultivars, many with bronze winter foliage.
Also try: Other spruces e.g Picea coreana.
barberry (Berberis thunbergii) Tough, with very beautiful foliage in summer and fall. Choose only new, non-invasive varieties.
red agate (Aesculus of Pavia) Colorful spikes of orange and red flowers bloom just in time to feed incoming hummingbirds.
Also try: Winterberry (Elex verticillata).
boxwood (boxwood) They are invaluable evergreen plants for foundation plantings, dwarf and medium hedges and for shearing to shape them.
rhododendron (Rhododendron) A wide range of plant sizes, flower colors and leaf sizes – all insisting on acidic (lime-free) conditions.
Also try: Heather (Kalona).
kiwi vine (Actinidia) A twining vine with bold leaves, sometimes with pink and white green leaves.
jasmine (Clematis) A large variety of spring and summer flowering, self-supporting vines in a wide range of flower sizes and colours.
Also try: Climbing hydrangea (Hydrangea petularis).
Shasta Daisy (Leucanthemum) The large white daisies face upward from the dark green foliage. Yellow and double-flowered varieties are also now available.
cranesball (Geranium) A variety of bushy or weed-strangling plants with saucer-shaped flowers in blue, pink, white and bicolor.
Also try: Hellebore (Helleborus).
snow drop (Galanthus) The beautiful white flower that tells us that winter is over. Beautiful, easy to grow and spreads steadily.
saffron (saffron) Cup-shaped flowers open widely in the sun to reveal a dazzling array of colours.
Also try: Snow Glory (Chionodoxa)
Autumn saffron (Colchicum) such as large-flowered crocuses in late summer and fall in purple, purple, pink or white.
lily (lily) flamboyant flowers in a wide range of colours, many beautifully spotted, on erect stems. Some are original.
Also try: Ornamental onions (garlic).
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Black raspberries (Aronia melanocarpa) An elegant shrub with shiny leaves, clusters of white flowers followed by edible black berries.
creeping trumpet (Campsis Radicals) A vigorous deciduous vine with loose spikes of large, orange flowers in late summer.
Also try: Columbine (Aquilegia canadensis).
Universe (Universe) Chamomile’s colorful flowers have golden eyes in red and many shades of pink and white on the feathery foliage. Good for cutting.
Sunflower (Helianthus) Easy annual plants from knee height to head height in a growing range of sunny colours.
Try also: Zinnia (Zinnia).
Tomatoes: Start by trying your favorite local varieties, but also try some of the newer introductions on the websites which are often more disease-resistant.
Cucumbers: Growing vining varieties in pots against a warm wall is often the best method.
Also try: zucchini.
Apples: Check with neighbors, or your extension service, to see which varieties do best in your area, and remember to check their pollination needs.
Strawberries: They grow well even in cold areas, but do not expect fruits in the first year.
Also try: sour cherries.
How long is the growing season in zone 4?
Hardiness Zone 4 in the United States has a fairly short growing season, which lasts an average of four months. There is still a wide variety of plants you can grow in this region of the United States, however many may need a little more care to keep them warm during the colder months, using horticultural wool, blankets or a greenhouse.
There are plenty of annuals that will grow well in Zone 4 during the summer. You may find our guides on growing cosmos or zinnias useful if you live in this area.