By Jake Overgaard
Extension Educator, Winona County
Pruning of raspberries is done to improve yield, ease of management/harvest, and to lower the incidence of disease by removing dead/dying tissue, increasing light penetration/air movement, and spray penetration. Below are some simple guidelines for pruning different types of raspberries. Remember that raspberries have perennial roots and biennial canes. The canes are distinguished as primocanes (1st year's growth) and floricanes (2nd year's growth).
Primocane Fruiting Raspberries aka Everbearing
- Prune floricanes to the ground after final harvest
- Thin primocanes (next year's floricane) late in the fall to 4-5 per linear foot (If concerned about hardiness, thin in the spring when winter survival is apparent)
- Head back (prune) floricanes in spring just below winter injury point, or no more than 25% the height of the cane
There are two options for primocane fruiting raspberries; they can be pruned to produce a summer and fall harvest, or a fall harvest alone. Pruning for fall berries alone is much easier, but there is more risk that you won't get a crop because of fall frost risk and because there is no summer crop.
If you want both summer and fall berries...
- Thin the primocanes (next year's floricane) to 4-5 canes per linear foot, select the best canes
- If concerned about hardiness, thin in the springtime when winter survival is apparent
- In the spring, prune the floricane a few inches below the last node that produced fruit as a primocane in the fall
- Cut all canes down to the ground in the Spring before growth starts. Yep, that's it
Black & Purple Raspberries
- Tip the primocanes (cut or pinch off the top 2-3") when they reach 24-30"
- Prune side branches to 12-18" on floricanes in the spring and select 4-5/hill
- After fruiting, cut floricanes to the ground
For more information on raspberry production, visit Raspberries for the Home Garden at http://z.umn.edu/83u.