In What Zones Can Concord Grapes Grow?

Concord grapes bear seeded, sweet fruits good for juice, jam or baking.

A selection of native American fox grape (Vitis labrusca), Concord yields dark violet fruits with a powdery white residue. Known as a slipskin type, with a leathery outer skin that easily slides away from the inner juicy flesh, Concord grapes contain seeds. This cultivar demonstrates considerable resilience to winter cold when dormant, unlike the more famous European wine grape types. It prospers across the central and northern parts of the United States, and is the most widely grown grape east of the Rocky Mountains.

Winter Hardiness

Based on average annual winter minimum temperatures, Concord grows in U.S. Department of Agriculture plant hardiness zones 3b through 9a. Some subfreezing temperatures must occur when the vine is dormant for long-term health, vitality and production of flowers each late spring. Significant vine cane dieback occurs in USDA zones 3 through 5 if cold, drying winds bombard the plant in winter. According to the University of Minnesota, Concord is not reliably hardy in USDA zones 3 and 4.

Regional Considerations

Although Concord is considered by horticulturists as a midseason ripening grape, insufficient time for ripening may occur in the northernmost U.S. For example, in USDA zones 3 and 4, early fall frosts in late September can severely damage grapes, causing them to burst. Therefore, grapes must be picked early to save them from frost or freeze damage. Their flesh flavor may not fully develop before fall cold causes leaves to turn color and drop away. A Concord grape plant needs at least 150 days of frost-free growing to develop ripe fruits for a good harvest.

Climate Zones

In the western United States, where highly variable elevation makes use of the USDA zones tedious and confusing, the Sunset climate zone system dominates. Concord grapes grow best in zones 2b and 3, 6 through 9 and 14 through 23. This grape does not fare well in the coldest, highest elevations of the Rockies, in arid deserts, along the Pacific Coast or where winters rarely endure frost.

Cultural Considerations

Concord grapes may grow well in USDA zones 3 and 4 if canes are removed in late fall and rested on the ground. Then place a 12- to 24-inch mulch over the canes to insulate them from brutal cold. The Maine Organic Farmers and Gardeners Association website notes that Concord grapes are hardy only to minus-15 degrees Fahrenheit without protection. Comparable dark-fruited fox grapes for colder winter regions include cultivars "Edelweiss," "Fredonia" and "Bluebell."

References

• Learn2Grow: Vitis Labrusca "Concord"
• "Sunset Western Garden Book"; Kathleen Norris Brenzel, editor; 2007
• University of Minnesota Extension; Growing Grapes for Home Use; Emily Hoover, et al.; 2008
• Maine Organic Farmers and Gardeners Association; Growing Grapes; John Fuchs

Resources

• National Gardening Association: USDA Hardiness Zone Finder
• Sunset Magazine: Find Your U.S. Sunset Climate Zone