Why You Should Prune Blueberries Bushes

Full Disclosure

First off, let me be completely upfront about this post: I planted my original blueberries nine years ago, and have never pruned them. They came in three-gallon containers, were well shaped from the start and have increased in production each year since I set them out. They have been wonderful producers and have given us plenty of berries to make delicious jams, cobblers and other desserts. I wasn’t concerned about pruning blueberries. Why risk screwing up a good thing?

Time For Action

They are getting really big. My four original plants are Vaccinium ashei (rabbiteye) varieties which, unpruned, may get to ten feet or taller. They also have a tendency to sucker heavily once established. In the meantime, since that first planting I have added a dozen Vaccinium corymbosum (highbush) plants of several varieties that will need care as well. Long story short, it’s time to reign them in before they get out of control.

What Will Pruning Blueberries Accomplish?

My objectives are to control the overall size of the plants, maintain good berry production levels, stimulate production of vigorous new shoots, and to maintain or improve fruit quality and size. Winter pruning allows you to see the bare branch structure easily and the swollen flower buds, making this the best time of year to get the job done. To end up with the results I hope for, a little understanding of blueberry “behavior” is needed.

Before Pruning, Know This

• Blueberries produce flowers and set fruit on wood that grew in the previous year, on established branches and potentially on suckers.
• Mature plants may produce thick, tall, unbranched canes (suckers) from the ground that reach seven feet or taller in a single season.
• The best production comes from canes that are between four and seven years old.
• The flower buds swell in late winter, making it easy to see where potential fruit exists.
• Pruning is known to decrease numbers but increase size of berries. It can also condense the ripening period. Pruning blueberries will also intensify production of new shoots.

My Plan

1. Scale back the plants to meet my size requirements by removing the oldest, least productive stems. Many of these old stems are not that tall, and are congesting the inner areas of the bushes or have spread too wide for the allotted space. To avoid over production of suckers, I will not remove all of the original stems this year but will take the worst example from each plant.
2. Remove all weak, spindly lateral branches from the remaining stems.
3. Cut the tall unbranched canes down to three or four feet, to force lateral branching and a lower canopy.
4. In the coming years, work toward attaining  better “age-balance” among the canes by removing the oldest stems annually. The ideal here is to have roughly equal numbers of 5-7 year, 3-5 year and 1-3 year old stems.

After nearly a decade of not pruning blueberries, I am anxious to find out the results of my work. If all goes well, I expect to have bigger berries, easier harvest and long lived plants. I’ll keep you posted.