Pruning raspberries in Oregon is a task directly tied to the mild winters, wet springs, and potential for fungal diseases common across the state. Consistent and timely pruning is the single most effective way to maximize berry yield and ensure the long-term health of the patch. Removing spent and weak canes increases light and air circulation, managing the moisture-loving pathogens that thrive in the Pacific Northwest. The correct timing depends entirely on the specific fruiting habit of the raspberry variety being grown.
Distinguishing Between Raspberry Varieties
Raspberry plants are categorized by when they bear fruit, which determines their pruning schedule. Summer-bearing varieties, known technically as floricane-fruiting types, produce fruit on canes that grew the previous year. These first-year canes are called primocanes, and they become the fruiting floricanes in their second year before dying off.
Fall-bearing varieties (primocane-fruiting types) produce fruit on the tips of the current season’s growth (primocanes), typically from late August until the first frost. The lower portion of these canes survives the winter and produces a second, smaller crop the following summer, becoming floricanes. Pruning is simply the systematic removal of canes that have finished their productive life.
Pruning Schedule for Summer-Bearing Varieties
The pruning for summer-bearing raspberries involves two distinct phases to maintain plant vigor. The first phase occurs immediately after the summer harvest, typically in late July or August, when all spent floricanes must be removed. These canes are woody, often brown, and have already produced fruit; cutting them down to the ground prevents them from becoming a source of disease.
The second, more significant pruning happens during the plant’s dormant period, ideally in late winter before new growth begins, which in Oregon is generally February or early March. During this late-winter thinning, the patch is cleared of all weak, damaged, or overcrowded new primocanes. Only the thickest, healthiest primocanes should be retained, with a density of about four to eight canes per linear foot of row.
These remaining vigorous canes are then tipped to a manageable height (five to six feet), which encourages the development of fruiting laterals lower down. Performing this final cut before spring rains ensures the plant focuses its energy on developing the remaining canes for the summer harvest.
Pruning Schedule for Fall-Bearing Varieties
Fall-bearing varieties provide the option of either a single, large autumn crop or two smaller crops. For a single, substantial fall harvest, the most straightforward approach is to cut every single cane down to the ground in late winter, typically from late February through early March. This complete cut-back eliminates the summer crop but concentrates the plant’s energy into producing a dense flush of new primocanes that will fruit in the fall.
If a grower prefers a double-cropping system, the pruning is more nuanced, involving the removal of only the fruited cane tips after the fall harvest. The bottom portion of these canes is left to overwinter and produce a smaller summer crop the following year. After this second, smaller summer crop is harvested, the entire two-year-old cane is then removed at the ground level, ensuring the patch remains clear of spent wood.
The major cut-back for either option must be timed for the dormant season to minimize stress. Waiting until late winter, just before bud break, is important in Oregon to allow the plant maximum time to reabsorb nutrients from the canes into the roots before they are cut.
Essential Techniques and Cane Management
Beyond timing, proper technique is necessary for maintaining a healthy patch. All cuts should be made with sharp, clean pruning shears to ensure a smooth cut that heals quickly, minimizing entry points for pathogens. Sanitation is particularly important in Oregon’s wet environment, which favors diseases like cane blight and spur blight.
When thinning, leave the strongest primocanes spaced approximately six inches apart to promote air circulation and dry foliage quickly after rain. Any diseased canes, such as those with purple blotches or split bark, should be removed immediately and disposed of away from the garden area. Raspberries benefit from a support system, with canes tied to a trellis or wires to prevent sprawling and improve light exposure and airflow.