By Kelly Miller
Raspberries are easy to grow but occasionally pruning raspberries helps keep your shrubs healthy and producing an abundance of tasty fruits.
Raspberries grow well throughout most of North America, from zones 3–9. Although there is a species native to North America, the American red raspberry (Rubus strigosus), there are many cultivars available that were developed from the European raspberry (Rubus idaeus). The Rubus idaeus varieties are quite popular among home gardeners and grow well throughout much of North America.
Pruning is an essential part of caring for raspberry shrubs, but knowing when and how to prune can be a bit confusing. Let’s step through all you need to know about pruning raspberry shrubs for organized growth and strong harvests.
Understanding Your Raspberry Plants: Primocanes and Floricanes
Raspberry plants are perennial and can produce fruit for more than 10 years. However, a raspberry shrub’s individual woody stems—known as canes—are biennial, which means they live for just two years.
Raspberries produce two types of canes – primocanes and floricanes. Primo means “first” in Italian, and a primocane is a cane in its first year of growth. Floricanes are raspberry canes in their second year of growth.
The terms primocane and floricane refer to the age of a cane, not to varieties of raspberries. However, some raspberry varieties are described as primocane-fruiting or fall-bearing, while others are floricane-fruiting or summer-bearing.
- Primocane-fruiting shrubs produce berries on canes in their first year (their primo year) of growth in late summer and fall.
- Floricane-fruiting shrubs don’t produce berries on primocanes. They bear fruit on second-year canes during the summer months.
Knowing Which Type of Raspberry Plant You Have
If your raspberry plant bears fruit in September or October, it’s a fall-bearing variety. If it bears fruit between June and August, it’s a summer-bearing variety. If you have it, you can also check the plant label or seed package to find out which type you have.
When to Prune Raspberries
Prune raspberries annually in early spring or late winter. Many growers also prune in the fall. However, in the fall it may be trickier to tell live canes from dead ones. Plus, old canes that are left in place during the winter will continue sending helpful carbohydrates and nutrients into the root system. Pruning raspberries in early spring is recommended and it’s also a good time to generally prune to reduce your shrub’s size if it’s getting too dense or sprawling, making it difficult to harvest the berries.
How to Prune Raspberries
To cut back a raspberry plant, you’ll need thick gloves and pruning shears.
Raspberry roots can spread aggressively. One purpose of pruning raspberries is to remove new canes that are growing outside of their rows. Note that the ideal row width for raspberries is just two feet (60cm). Cut these canes down to ground level or simply mow the perimeter of the rows.
Pruning Summer-Bearing Raspberries
A summer-bearing raspberry patch that’s more than one year old has the previous year’s primocanes and floricanes growing side by side. Primocanes should be preserved, while “spent” floricanes at the end of their life cycle should be pruned. So, it’s important to know how to tell them apart.
Primocanes are thicker and bend easily. Floricanes are thinner and brittle and may hold old, dried-up fruit clusters. You can try breaking a few canes to help with identification. Spent floricanes easily snap, revealing brown, woody flesh. Primocanes are more resistant to breaking. If you do snap one, the revealed flesh will be green.
Remember, the floricanes are dead, while the primocanes are merely dormant.
When pruning raspberries it’s important to identify the spent floricanes. These canes should be removed. However, it’s not necessary or helpful to yank them out. Simply snip off the canes at the soil level.
After removing spent floricanes, move on to pruning any damaged or diseased canes. Then, it may be helpful to remove some healthy primocanes to thin out the patch and prevent overcrowding.
Pruning Fall-Bearing Raspberries
To prune a fall-bearing raspberry patch, simply cut all of the canes down to ground level. The new growth that emerges later on in spring will produce fruit in the fall. Alternatively, you can leave some canes behind. These will make fruit in summer, thus extending the length of the patch’s harvest season.
Finally, post-pruning is a good time to install a support system, such as a trellis, fence, or tomato stakes. Providing support spaces out canes. This helps prevent the spread of disease and improves access to sunlight.
How Important is Pruning Raspberries?
What happens if you don’t prune your raspberry shrubs? Pruning is a necessary part of growing raspberries. Unpruned shrubs become overcrowded, forming a thick mass of weak canes. As the canes compete for sunlight, the lower half of the shrub will be shaded out and begin to die. Meanwhile, fewer branches will produce fruit and that fruit will be smaller and less tasty.
Gardening for a Sweet Tooth
Homegrown raspberries are ideal for topping off desserts, pancakes, or a bowl of cereal but shrubs do require a fair amount of space to grow. If you’re looking for something on a smaller scale, try growing the most popular garden fruit: strawberries! Plant strawberries once and you will enjoy several years of fruit production. Get started with our Top Tips for Growing Strawberries.
