Zone 3
Among the coldest gardened places in the lower 48: high northern mountains and the far northern plains. Short seasons and deep cold limit woody plants to the toughest species.
What zone 3 means
Zone 3 covers places where the average coldest night of the year falls between -40 and -30 °F (-40 to -34 °C). Zone 3a is the colder half (-40 to -35 °F) and zone 3b the warmer half (-35 to -30 °F).
A plant rated “hardy to zone 3” is expected to survive that typical winter low with its roots in the ground. 53 plants in the catalog reach the cold edge of their range here — give those a sheltered spot, good drainage and winter mulch.
What the zone doesn’t tell you
- Summer heat and humidity — many plants rated for zone 3 still fail from heat, especially in the Southeast.
- Rainfall and drainage — cold plus wet soil kills plants that would survive cold in dry soil.
- Frost dates — the length of the growing season is a separate question; check local frost dates.
- Your microclimate — walls, slopes, pavement and wind shift conditions by half a zone or more across one property.
Find your exact zone on the USDA Plant Hardiness Zone Map, then treat it as one filter among several. The planner’s OL-HARDY check uses the zone you set for the site.
Catalog plants rated for zone 3
Hardiness is necessary, not sufficient: check light, moisture and soil on each plant page, and prefer plants native to your region. Filter the plant library by zone 3.
Trees (5)
Red maple · Sugar maple · American hornbeam · Russian olive · White oak
Conifers (7)
White fir · Eastern red cedar · Dwarf Alberta spruce · Colorado blue spruce · Eastern white pine · Emerald Green arborvitae · Eastern hemlock
Shrubs (12)
Black chokeberry · Summersweet · Red twig dogwood · Northern bush honeysuckle · Annabelle smooth hydrangea · Limelight panicle hydrangea · Winterberry · Diabolo ninebark · Mops dwarf mugo pine · Gro-Low fragrant sumac · Common lilac · Arrowwood viburnum
Grasses (3)
Blue grama · Little bluestem · Prairie dropseed
Perennials (20)
Common yarrow · Eastern red columbine · Swamp milkweed · Butterfly weed · Blue false indigo · Moonbeam threadleaf coreopsis · Purple coneflower · Stella de Oro daylily · Sum and Substance hosta · Autumn Joy sedum · Siberian iris · Dense blazing star · Cardinal flower · Wild bergamot · Walker's Low catmint · Garden peony · Husker Red foxglove beardtongue · Goldsturm black-eyed Susan · Black-eyed Susan · New England aster
Groundcovers (7)
Canadian wild ginger · Pennsylvania sedge · Blue Rug creeping juniper · Golden ragwort · Moss phlox · Christmas fern · Foamflower
Vines (1)
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