USDA Plant Hardiness Zone 4

USDA Plant Hardiness Zone 4 extends across the uppermost United States. Some of the geographical regions included in this zone include parts of Idaho, Montana, Wyoming, Minnesota, Wisconsin, South Dakota, Nebraska, Vermont and Maine. Although the climates may vary, the winters are characterized by having average low temperatures in the range of -30 to -20 degrees F. Plants benefit from a 3"-4" layer of mulch, which helps protect the roots and prevent some plants from heaving out of the ground during spring thaws.

Plants that prosper in Zone 4 include:

Trees

Deciduous

Trees for outstanding fall color:

• Autumn Blaze Maple (Acer freemanii 'Jeffersred') – also called the Freeman Maple, the fast-growing Autumn Blaze Maple is the result of crossing American Red Maple and Silver Maple
• Autumn Purple Ash (Fraxinus americana 'Autumn Purple') – the largest Native American ash tree, with purplish shading on yellow fall leaves
• Tulip Poplar (Liriodendron tulipifera) – very tall (to 90 feet) with leaves and flowers shaped like tulips and bright-yellow fall foliage

Evergreens

Use these evergreen trees as wind screens during cold Zone 4 winters:

• Emerald Green Arborvitae (Thuja occidentalis 'Emerald Green') – tall, pyramidal shape quickly grows into a disease-resistant evergreen hedge
• Skyrocket Juniper (Juniperus scopulorum 'Skyrocket') – good for narrow spaces, this slender tree has bluish-green foliage

Flowering Trees

For a succession of flowers, plant trees that have different bloom times, such as:

• Eastern Redbud (Cercis canadensis) – a native tree with rose-pink flowers, blooming in spring before the leaves appear
• Jane Magnolia (Magnolia x 'Jane') – spectacular pink, tulip-shaped flowers cover small trees (10-15 feet) in early summer

Shrubs

Plant these shrubs to round out your landscape design by adding texture and color:

• Hetz Midget Arborvitae (Thuja occidentalis 'Hetz Midget') – a dwarf Thuja shrub with evergreen appeal
• Endless Summer Hydrangea (Hydrangea macrophylla 'Endless Summer') – a cold-hardy hydrangea that blooms continuously during the growing season, sporting large mophead flowers

Rose Bushes

Zone 4 gardeners are at the northernmost (coldest) range of these two outstanding roses:

• Oso Easy Rose (Rosa x Oso Easy®) – as its name implies, the Oso Easy Rose is a low-maintenance gem that is disease-resistant and needs no deadheading
• Drift Roses (Rosa 'Apricot Drift') – a colorful groundcover, Drift Roses have a spreading habit and offer continuous flowering throughout the growing season

Citrus

Although citrus plants cannot grow outside year-round in Zone 4, gardeners can cultivate citrus fruits in heated greenhouses in this cold climate. For non-greenhouse gardeners, simply grow these citrus plants in containers, which can be moved indoors during cold weather and back outdoors in summer:

• Meyer Lemon (Citrus x meyeri) – a delightful alternative to taller lemon trees, this lemon-orange hybrid is a champion in containers
• Key Lime (Citrus aurantiifolia) – smaller than supermarket limes, Key Limes grow on small plants that are beautifully ornamental in pots
• Calamondin Orange (Citrus mitis 'Calamondin') – these small citrus fruits resemble tangerines and may bear fruit year-round under optimal conditions

Fruit Trees

Zone 4 gardeners can grow many fruits in their own backyard, including:

• Dwarf McIntosh Apple (Malus domestica 'Honeycrisp') – plant another apple cultivar, such as the Dwarf Gala Apple, to ensure cross-pollination and fruit formation
• Rainier Cherry (Prunus avium 'Rainier') – beautiful cherry blossoms in spring are followed by sweet cherries in summer
• Contender Peach (Prunus persica 'Contender') – a cold-hardy peach tree, which produces late-season flower buds that aren't damaged by late frosts

Berries

Easy to grow, low maintenance and pest-resistant, these berries thrive in Zone 4:

• Lingonberry (Vaccinium vitis-idaea) – small evergreen shrubs produce two harvests of delicious lingonberries each year
• Stevens Cranberry (Vaccinium macrocarpon 'Stevens') – grow Stevens Cranberry for its harvest of berries as well as a beautifully ornamental and evergreen groundcover
• Sweetheart Blueberry (Vaccinium corymbosum 'Sweetheart') – a hybrid cross between Northern and Southern highbush blueberries, Sweetheart produces two crops each year

Container Plants

These plants are not in Zone 4's hardiness range, but they are easily grown in pots that you can move indoors when cold weather threatens:

• Sago Palm (Cycas revoluta) – a smaller palm that excels as a houseplant
• Dwarf Cavendish Banana (Musa acuminata) – although Zone 4's growing season is not typically long enough for banana plants to produce fruit, add a tropical touch to your garden by growing Dwarf Cavendish Banana as a foliage plant