Raspberries have perennial roots and crown with bi-annual canes. Each year, new canes appear and grow vegetative manner. Those same canes give us the berries the second year and then die. This cycle is repeated each year and left unpruned gives us that unmanageable bramble patch in just a few years. Annual pruning involves the removal of those 2-year-old dead canes each spring if they have not been removed the previous summer.
We prune to encourage a good juicy crop, along with better air and light through the canes. Another good reason to prune properly is to prevent the buildup of disease problems.
There are two types of raspberries. The one we know well are the summer bearing types. The other is a fall bearing type. While these two varieties bear fruits for us in different seasons, they are maintained in a similar manner. Both kinds will be pruned in the early spring before any growth resumes while the different kinds of canes are easily seen and identified. Depending on our early spring weather, pruning could begin as early as February 15 and could continue through the end of March. The goal for mature planting would be to have viable fruiting canes 6 to 8 inches apart with a row about two feet wide. You would have fewer fruiting canes the first 2 to 3 years.
For the typical summer-bearing red raspberry:
- During the summer, after harvest, cut the canes at ground level
- During the dormant season, remove all weak canes (under pencil size, winter damaged or diseased canes)
- If the fruiting canes were not removed last season, now is the time (February 15 through end of March)
For fall-bearing (and yellow raspberries):
- The fall crop shows up on the upper part of the cane
- Pruning after they fruit means just removing the dead portion (year one)
- They will fruit again the next season farther down the cane and then the remainder of the cane dies (end of second year)
- Prune the entire cane away after the summer crop as you would the red raspberry
- If the fruiting canes were not removed last season, now is the time
- If you do not want to do any spring pruning, you can cut the entire fall raspberry plant down to the crown after the fall crop and you will get only the fall crop each year
For more information on raspberries, visit extension.illinois.edu/raspberries
The Kendall County Master Gardener Help Desk resumes for 2018 in March – Monday, Wednesday and Friday from 9 a.m. to 12:30 p.m. at 630-553-5823.
Richard Hentschel is a Horticulture Extension Educator with University of Illinois Extension, serving DuPage, Kane and Kendall counties. Stay tuned to more garden and yard updates with This Week in the Garden videos at facebook.com/extensiondkk/videos and the Green Side Up podcast at go.illinois.edu/greensideup.