In this video, David Handley, a vegetable and small fruit specialist for the University of Maine Cooperative Extension, explains what to look for when pruning highbush blueberries. He demonstrates proper pruning techniques on a bush that’s about 20 years old.

Typically blueberries are pruned in the dormant season

In Maine, that means the end of December through the end of March. Pruning too early in the fall may cause the bushes to sprout and get winter injury. Pruning too late in the spring will cause them to bleed and will create an opportunity for diseases to infect them.

Open up the interior of the blueberry bush

When you are pruning a highbush blueberry, you want to maintain the basic height but open up the bush to allow in sufficient light. This will increase the size and quality of the fruit and allow it to mature earlier. It will also improve air circulation, reducing the opportunity for diseases to take hold.

Reduce the number of canes

From a mature bush like the one in the video, you want to end up with six to 12 canes growing from the base of the plant. These canes, which provide the bush’s upright structure, should be from one to six years old. Every year a blueberry bush will produce new canes, and the process of removing canes involves cutting out the smaller, weaker ones. It also involves cutting out a few older canes. Canes older than six years produce weaker wood and should always be removed.

Thin the shoots

After removing canes, it’s time to thin the shoots. Blueberry shoots have two types of buds: (1) fruit buds, which will produce flowers and then fruit, and (2) vegetative buds, which will produce new shoots. A desirable shoot has fruit buds at the tip and vegetative buds at the base. Shoots with few or no buds should be removed, and smaller shoots can be removed as well.