Planting Calendar & Monthly Lists
Scroll to Map & Zone DescriptionNOTE: No Planting in Winter Months.
Extreme Minimum Temperate −34.4 to −31.7°C (−30 to −25°F)
Temperate with Mild Summers and Cold Winter
Indicative Towns: Minneapolis/St.Paul, Minnesota; Lewistown, Montana
Zone 4a includes semiarid steppe, alpine and humid continental (cool summer) climates and northern mountainous areas. It includes most of Alaska and northern areas of USA. Lewistown experiences a relatively dry humid continental climate (Köppen Dfb) with long, dry and usually cold winters and short, warm, wetter summers.
Zone 4 (a & b) has more opportunities for growing vegetables and herbs with a slightly extended growing season and warm summers. Start plants early indoors or purchase seedlings grown in a greenhouse. Adding a good layer of mulch and covering plants during last frosts can help more plants survive the cold winters.
Vegetables to add to Zone 2 & 3 lists for growing in Zone 4 include: Rhubarb, Okra, Pumpkins,
Eggplant and Melons. Extra herbs to grow include: Angelica, Sage, Lemon balm,
Mint, Thyme and Winter savory.
Towns include:
Belgrade, Montana
Big Lake, Minnesota
Billings, Montana
Bismark, North Dakota
Dargo, North Dakoka
Fergus Falls, Minnesota
Glasgow, Kentucky
Glendive, Montana
Grand Forks, North Dakota
Greenville, Maine
Jamestown, North Dakota
Minneapolis,
Minnesota
Minot, North Dakota
Montpelier, Vermont
St. Cloud, Minnesota