How to Prune Blueberries

About 5 years ago, after considerable research, I bought 3 varieties of blueberries that complimented and cross-pollinated each other, so I’d have blueberries nearly the whole growing season. I was told this would be simple.

Oh, how pathetic my wilting and tiny blueberry shrubs were a year after I planted them in my alkaline, hard clay soil in Pennsylvania. And forget about fruit—1 berry per bush if I was lucky. It turns out the soil in my area was the exact opposite of what a blueberry bush needs: well-drained, highly acidic, loamy soil.

After two years, I was about to put them out of their misery. But instead, I gave it one last shot and moved the blueberries to a raised garden bed so I could control the soil conditions. I loaded the soil in the garden bed with peat moss. To that, on a regular basis, I added elemental sulfur and compost for 2 years. Now the soil is almost where it needs to be, at a pH of 5 (but I’d like to get it to 4). Oh, and the plants look great and are producing small crops of berries for the first time.

Pruning blueberries is essential to their health

To get a great crop of blueberries every year, one also has to prune the shrubs every winter. Not spring or fall, but during the winter when the plant is dormant. Pruning is a little tricky in the beginning, but the video below from the University of Maine explains clearly how to prune blueberries and why.

The goal of pruning blueberries is to prune out older, less productive canes and leave the newer canes.

Blueberries fruit on 1-year-old shoots; you’ll see the swollen buds at the tip of the canes. The swollen buds are the fruit buds, which break in spring, producing flowers and fruit. Always prune out the smaller canes with few fruit buds and vegetative buds, as they won’t produce much fruit.

Every winter, prune the old, graying canes, which are frequently covered with lichen. They’ll be growing from the base and should be removed at ground level with loppers because they shade out new growth. There should be no canes on the blueberry bush older than 6 years.

When pruning the top of the plant, leave the strong shoots and trim out the weak shoots (small twig-size). In fact, these can be snapped off by hand due to their small size.

The goal is to prune out 50–75% of the blueberry bush. While this may sound too aggressive, it’s not. In fact, the aggressive pruning results in a bush that’s far more productive, with larger, sweeter blueberries.

Prune out the weak fruiting wood so the bush doesn’t try to support way too many fruits. Without pruning, your fruit would be very small and would tend to ripen rather late. It also makes the plant more susceptible to disease because so much of the bush will be shading itself. The idea, just as with pruning fruit trees, is to open the plant up to light and air so it heats up faster, can conduct photosynthesis more efficiently, and dries faster after rain.