Growing plants in some of the high altitude areas of East Idaho and Western Wyoming where extreme cold temperatures often occur can be frustrating and difficult. By planting varieties that are genetically tolerant of harsh weather conditions you can greatly increase your chances for success. Following is a list of plants that have been proven to tolerate extreme cold temperatures. All plants on this list are USDA hardiness zone 3 unless noted in parenthesis as zone 2. Zone 3 means the plant has been known to survive temperatures of -40°F. Zone 2 indicates that the plant has been known to survive -50°F.

Many other factors can affect the ability of a plant to survive cold temperatures. Some of these factors include excessive wind, lack of snow cover, rapid temperature changes, unusually early fall or late winter cold snaps, high pH of the soil, sun exposure, etc. Therefore, a plant that may survive well in a situation where it receives good early snow cover and is protected from the winter sun and prevailing winds may not survive nearby where those conditions are not met.

Note: An asterisk (*) indicates that the plant requires an acidic soil to do well.

A plus sign (+) indicates that the plant should be protected from harsh winds, especially in the winter.

Shade and Flowering Trees

Ash, Marshall

Ash, Patmore (2)

Aspen, Quaking (2)

Aspen, Swedish (2)

Birch, Cutleaf Weeping (2)

Birch, European White (2)

Birch, Paper (2)

Birch, Young’s Weeping (2)

Caragana, Weeping (2)

Cherry, Canada Red (2)

Hackberry, Common (2)

Linden, Redmond

Locust, Purple Robe

Maple, Amur* (2)

Maple, Emerald Lustre

Maple, Parkway

Maple, Tatarian

Mayday Tree

Mountain Ash, European (2)

Oak, Bur

Pear, Prairie Gem

Plum, Cistena Tree Form

Plum, Rose Tree of China (2)

Poplar, Robusta

Poplar, Siouxland

Poplar, Theves Lombardy (2)

Russian Olive (2)

Sumac, Cutleaf Staghorn

Sumac, Smooth

Sumac, Staghorn

Willow, Golden

Willow, Laurel Leaf (2)

Willow, Prairie Cascade

Evergreen Trees

Arborvitae, Pyramid

Juniper, Wichita Blue

Juniper, Tolleson’s Wpg

Pine, Eastern White

Spruce, Alberta +

Spruce, Baby Blue Eyes

Spruce, Black Hills

Spruce, Colorado (2)

Spruce, Fat Albert

Spruce, Hoopsi (2)

Spruce, Norway (2)

Spruce, Norway Wpg (2)

Evergreen Shrubs

Arborvitae, Hetz Midget

Arborvitae, Little Giant

Arborvitae, Woodward

Fir, Dwarf Balsam

Juniper, Blue Chip

Juniper, Buffalo

Juniper, Calgary Carpet

Juniper, Tam

Pine, Mugo (2)

Spruce, Blue Nest (2)+

Spruce, Dwf. Norway (2)+

Spruce, Globe Blue (2)

Spruce, Nest (2)+

Tall Deciduous Shrubs (4′ and up)

Buckthorn, Fernleaf

Buckthorn, Tallhedge

Cherry, Nanking (2)

Chokeberry, Autumn Magic

Chokecherry, Native (2)

Cotoneaster, Peking

Dogwood, Bailey (2)

Dogwood, Isanti (2)

Dogwood, Ivory Halo

Elderberry, Golden

Forsythia, Meadowlark

Forsythia, Northern Gold

Honeysuckle, Copper Dwf.

Honeysuckle, Dwf. Bush

Lilac, Beauty of Moscow

Lilac, Common Purple (2)

Lilac, Katherine Havemeyer

Lilac, Ludwig Spaeth

Lilac, Miss Canada (2)

Lilac, Miss Kim

Lilac, Mme. Lemoine

Lilac, Monge

Lilac, Mount Baker (2)

Lilac, Pocahontas (2)

Lilac, President Grevy

Lilac, Sensation

Lilac, Tinkerbelle

Mockorange, Blizzard

Ninebark, Dart’s Gold (2)

Ninebark, Diabolo

Ninebark, Nugget

Peashrub, Siberian (2)

Plum, Cistena

Plum, Rose Tree of China (2)

Snowball Bush

Snowberry, White

Spirea, False Ash Leaf (2)

Spirea, Vanhoutte

Sumac, Cutleaf Staghorn (2)

Sumac, Smooth (2)

Sumac, Staghorn (2)

Viburnum, Alfredo (2)

Viburnum, Bailey Compact (2)

Low Deciduous Shrubs (Under 4′)

Bearberry Kinnickinnick*

Currant, Alpine (2)

Hydrangea, Annabelle

Lilac, Dwarf Korean

Potentilla, All Varieties (2)

Spirea, Goldflame

Spirea, Goldmound

Spirea, Little Princess

Spirea, Magic Carpet

Sumac, Gro-Low

Vines

Honeysuckle, Dropmore

Hops, Nugget Ornamental

Ivy, Engelman

Ivy, Virginia Creeper

Grape, Beta

Grape, Valiant

Roses

Belle Poitevine

Blanc Double de Coubert

Champlain

Cuthbert Grant

David Thompson

George Vancouver

Hansa

J.P. Connell

Morden Blush

Morden Centennial

Morden Fireglow

Rugosa (2)

Therese Bugnet

Winnipeg Parks

Climbers:

Henry Kelsey

John Davis

William Baffin

Fruit Trees

Apple, Haralred

Apple, Sweet Sixteen

Apple, Yellow Transparent

Apricot, Scout

Pear, Golden Spice

Plum, Toka

Small Fruits

Cherry, Nanking (2)

Chokecherry, Native (2)

Currant, Red Lake

Elderberry, Adams

Gooseberry, Pixwell

Grape, Beta

Grape, Valiant

Lingonberry, Red Pearl (2)*

Raspberry, Amity

Raspberry, Golden Summit

Raspberry, Latham (2)

Raspberry, Summit