Blueberry Plants in the Winter

Dormancy

Blueberries go dormant during the winter months when the days become shorter and temperatures drop below 45 degrees Fahrenheit. Flower and leaf buds develop in late summer and throughout fall, but they stop all development when the plant enters dormancy. Once the bush becomes dormant it tolerates prolonged periods of freezing weather without damage. Blueberries that don't go dormant in winter won't develop fruit the following year. It's important to plant varieties developed for your climate to ensure the plants can go dormant and break dormancy at the correct time.

Winter is planting time for new blueberry bushes. Dormant 2- to 3-year-old bare root nursery plants go in the ground in late winter, usually in February or March as soon as the soil thaws enough to dig the planting hole. Container-grown blueberries go in the bed in early winter before the ground begins to freeze but after the plants enter dormancy. Planting during the dormant season causes less shock to the plants which helps them adjust more quickly to their new bed when they begin actively growing again in spring.

The bushes don't require severe pruning until they are approximately 5 years old. Light pruning in the first five years occurs during the winter dormant season. Most bushes only require removal of dead and damaged canes and any twiggy growth near soil level on the main stems. Mature blueberries that are more than 5 years old are primarily pruned in summer after the berry harvest, but they may need some winter pruning to control their size. Removing a third of the oldest canes keeps the bush size more manageable.

Planting the right variety for your region helps ensure your blueberries survive winter cold. Varieties that fruit early usually flower earlier, which isn't suitable in climates that experience late season freezes. Professional growers use overhead irrigation to protect early flowering blueberries from late freezes, but this method isn't suitable for use in the home garden. Pruning mature bushes immediately after harvest forces the plants to flower later in the spring, providing some protection from frost damage. Covering the plants with a frost blanket may also provide some protection if a freeze is expected once the bushes begin to flower.