Is it Too Cold for Blueberry Plants in Minnesota?

Types of Blueberry Shrubs

• The only blueberries with demonstrated cold hardiness to the Minnesota climate are hybrids of Northern highbush blueberry (Vaccinium corymbosum) with the compactness and exceptional cold-hardiness of lowbush blueberry (V. angustifolium). These hybrids are sometimes called "half-high blueberries." The University of Minnesota Extension recommends these cultivars: Northblue, Northcountry, Northsky, St. Cloud, Polaris and Chippewa. Minnesota is in U.S. Department of Agriculture Plant Hardiness Zones 3 and 4, which are too cold for reliable survival of other blueberries grown in other areas of the United States.

Growing Requirements

• When growing half-high blueberry varieties in Minnesota, meet other growing conditions to ensure their health and longevity. The soil must be strongly acidic, ideally with a pH 4.0 to 5.0. Minnesota's soils are often loamy clay with a neutral to alkaline soil, although in northeastern Minnesota's conifer woodlands, the soils are naturally acidic. Western Minnesota's soils are alkaline and prairie winds are deadly in winter. Blueberries need a loose, crumbly soil rich in organic matter and remain evenly moist, never soggy. Plant them in a full sun exposure in a wind-sheltered spot.

Animal Threats

• Animals challenge Minnesotans. If fruits develop on the half-high blueberry shrubs, various songbirds will visit the plants and quickly steal the berries. Netting is needed to keep birds from fully rendering a productive plant barren. Rabbits will eat the twigs of blueberries in fall and winter when other foods are scarce. Wire fence caging is necessary to protect shrubs, especially in the southern and western counties in Minnesota.

Fruit Production

• Winter survival is key to blueberry production in Minnesota. Regardless of winter threat, ample branches must survive in order for flowering and fruiting to be possible. Blueberries bloom on twigs that grew the previous year. Winter dieback of plants effectively ends the chance of flowering and fruiting for the next growing season. Prune with restraint, but remove all dead tissue in early spring. Prune so a good balance between existing flowering twigs as well as production new growth that will flower the next year.