How to Trim Blackberry Canes

Overview

Domestic blackberry vines are deciduous and will continue to produce fruit for 15 to 20 years in a temperate climate. Erect varieties of blackberry plants produce long, upright canes. Trailing varieties spread laterally along a fence or trellis. Blackberries fruit on second-year canes, according to the University of Florida IFAS Extension Program. The first year, non-fruiting canes are called primocanes; in the second year, when the canes produce fruit, they are called floricanes. After fruiting, the floricanes die out and are replaced by new growth. They need occasional trimming.

Step 1

Prune out the thinner, weaker stalks early in the growing season with pruning shears, leaving five or six healthy canes on each plant. Remove any dead or diseased-looking canes when you're pruning. Cut the stalks as close to the ground as possible.

Step 2

Trim the tips off the primocanes to encourage division and increased fruit production. Using a sharp pair of shears, clip off the top 1 inch of each cane. Trim the tips of erect varieties when the cane is 30 to 36 inches tall; trim trailing varieties when the canes are 46 inches long.

Step 3

Remove the floricanes after the harvest; these second-year canes will not reproduce and will eventually shrivel and die on the plant. Cut out the floricanes close to the ground to improve the plant's health and appearance.

Step 4

Thin and remove dead or diseased canes at any time of year. When trimming out diseased canes, sanitize your tools between each cut to avoid spreading diseases.