Summer-bearing raspberries, often called “floricane-fruiting” varieties, follow a distinct two-year growth cycle that dictates when and how they should be pruned for maximum productivity. Understanding the plant’s natural life stages and applying precise pruning techniques ensures that the plant directs its energy toward developing large, sweet fruit rather than maintaining non-productive wood.
Understanding the Raspberry Growth Cycle
Raspberry canes operate on a biennial system, meaning any single cane lives for two seasons. The first year of growth produces a cane known as a primocane, which emerges from the ground as a green, non-woody shoot. Throughout its first season, the primocane focuses on vegetative growth, gathering energy and establishing itself without producing any fruit.
The following spring, this cane transitions into a floricane. It is this second-year cane, the floricane, that develops lateral branches, flowers, and ultimately bears the summer fruit. After the harvest is complete, the floricane has fulfilled its biological purpose and begins to senesce, gradually dying back to the ground.
For summer-bearing varieties, this distinction is important because fruit production occurs exclusively on the floricanes. The pruning process, therefore, revolves around removing the spent floricanes and managing the healthy, new primocanes that will become the next season’s crop. Removing the dead wood is a fundamental step in maintaining the health and vigor of the entire raspberry patch.
When to Prune Summer-Bearing Varieties
Pruning for summer-bearing raspberries occurs at two distinct times of the year. The most immediate and important pruning takes place right after the summer harvest concludes, usually in late summer or early autumn. At this time, all canes that have just finished fruiting—the floricanes—must be identified and removed completely.
Cutting these spent canes back to the soil line prevents them from becoming reservoirs for fungal diseases, such as cane blight, which could otherwise overwinter and infect the new growth. This post-harvest pruning also immediately improves air circulation throughout the patch, which helps keep the remaining primocanes dry and less susceptible to disease.
The second instance of pruning occurs during the dormant season, typically in late winter or early spring before new buds swell. This later pruning focuses entirely on thinning and shaping the remaining primocanes, which are the future floricanes. This is the time to remove any canes that are weak, damaged, or growing too close together.
The Step-by-Step Pruning Process
Begin by identifying the canes that look dry, woody, and brown or gray; these are the spent floricanes that have already produced fruit. Use clean, sharp bypass pruners to cut these canes as close to the ground as possible, ensuring no stub remains above the soil line.
Do not confuse these dead floricanes with the still-green, vigorous primocanes, which are the future crop. Removing the spent wood should be followed by immediate disposal to prevent any lingering pests or diseases from reinfecting the patch. This action redirects the plant’s entire energy supply into the developing root system and the new primocanes.
The second stage of pruning, performed in late winter, involves thinning the remaining primocanes. The goal is to reduce cane density to encourage better sunlight penetration and air movement, which results in larger, healthier berries. Selectively remove the thinnest, shortest, or least vigorous canes until you have an ideal spacing of four to six strong, healthy canes per linear foot of row.
Any young canes that have sprouted outside of the intended planting width, typically a band 12 to 18 inches wide, should also be removed. If the remaining healthy canes are exceptionally tall, they can be tipped back slightly—removing just the top few inches—to encourage sturdier growth and prevent them from snapping in heavy winds.
Post-Pruning Trellising and Support
Once the dormant season thinning is complete, the remaining healthy primocanes must be secured to a support system. Raspberry canes, particularly when laden with fruit, require structural assistance to prevent breakage and keep the fruit off the ground. Common methods include the T-trellis or a simple post and wire system running along both sides of the row.
The canes should be loosely tied to the support wires using soft twine or plastic clips to maintain an upright position. Proper trellising ensures that sunlight reaches all parts of the plant and keeps the foliage and developing fruit separated from the damp soil.