How to Trim Raspberry Plants

How you prune raspberries depends on the variety.

Raspberries plants are unusual in that the roots are perennials living for many years, but the individual canes are biennial. Canes emerge in spring and spend their first year in a vegetative state. In the second year, the cane blooms and sets fruit. Knowing when and how to prune your raspberry canes increases branching, which in turn increases the yield of these juicy berries. Pruning varies among varieties.

Things You'll Need

• Pruning shears

Instructions

1. Prune summer bearing raspberries immediately after the crop has been harvested. Cut the fruit-bearing canes to ground level. The Washington State University Extension recommends thinning the new canes, or primocanes, to 10 to 12. Once pruned, tie the new canes to a trellis in preparation for next year's harvest.

2. Prune fall-bearing raspberries by cutting all canes back to ground level in the fall once the plant has gone dormant. According to Washington State University, this prevents winter damage to canes and reduces the risk of insects and disease. The University of Illinois suggests waiting until March or April before cutting canes back to the ground and notes that this delays fall fruiting, but increases yield.

3. Prune black and purple raspberries in the summer by cutting back the top 3 to 4 inches of each cane once they have reached a height of 2½ to 3 feet. This encourages side shoots that also produce fruit. Once canes have produced fruit and harvesting is complete, cut old canes back to ground level. Thin the remaining canes by removing any that are less one-half-inch in diameter.

References

• Washington State University Extension: Pruning Raspberries
• Purdue University Consumer Horticulture: Prune, Propagate Raspberries for Tidy Garden, Better Crop
• Iowa State University Extension: Pruning Raspberries

Resources

• Ohio State University Extension: Raspberries for the Backyard Fruit Planting