Q. How do I prune raspberries in my garden?
Pruning is an important factor in raising a bounty of tasty raspberry (Rubus) fruit.
Pruning instructions can be very confusing, since there is more than one way to do it. However, not pruning leads to an unproductive, disease-prone, tangled, thorny mess. When winter weather subsides, you can tame your raspberry bramble patch with proper and timely pruning techniques.
To start, some supplies are needed: protective gloves, sterile, sharpened hand pruners, a leaf rake, hoe or other cultivating tool, and organic mulch. Also, constructing a trellis is an option--it's helpful in making the brambles manageable.
Black raspberries grow in a bushier form, and purple raspberries are black-red hybrids which also grow as a bush.
There are three basic categories of raspberry, (1) summer-bearing, also called floricane; (2) fall-bearing, also known as primocane; and (3) the purple and black raspberry type. All three require specific early-spring pruning techniques.
Floricane-fruiting types (red summer-bearing raspberries)
To prune summer-bearing raspberry plants, look for tall canes growing in the patch. Only prune to the ground canes with clusters of side branches where fruit was previously picked. Also, cleanly remove any brittle, dead wood. You're left with the first-year canes, which are straight and show no evidence of old flowers and fruit clusters. These canes will bear fruit from the top down in their second summer. However, if there are too many canes growing close together you won't get the best quality fruit, so more pruning is required. Cut the thinnest canes, leaving the strongest canes spaced at least 6 inches apart. Also remove any little spindly crooked sprouts; these are runts that won't produce fruit.
For general maintenance of summer-bearing raspberries, prune fruited canes as soon as you finish harvesting them.Some cultivars of red summer-bearing raspberries include: Boyne, Canby, Citadel, Encore, Killarney, Latham, Liberty,
Primocane-fruiting, or red ever-bearing, (also called fall-bearing) which include gold raspberries, are just a variation of red raspberries. Some cultivars include: Amber, Autumn Bliss, Autumn Britten, Caroline, Fall Gold, Fall Red, Goldie, Heritage, Jaclyn, Redwing, and Ruby.
There are two options for pruning ever-bearing raspberries.
Option 1: You have a mass of canes with evidence of fruiting. Some will have fruited this year on the top foot or so of the cane. These can be left to continue fruiting this summer for the early crop, but cut off the end of the cane where fruit has already grown. Other canes show old fruit sprays all the way down. They are finished bearing and should be removed by cutting at ground level. Now thin out the canes you have left, by taking out the smallest and leaving at least six inches between canes. Also remove dead and any weak scrawny sprouts of wood. As soon as the remaining canes bear fruit early in the summer, they can be cut out, leaving space for the new growth of canes.
Option 2, the one-crop method: This method makes pruning a lot quicker and easier by cutting all of the canes now. Why do this? The main crop of raspberries is in the fall. This is when you'll get the best quality fruit. Early crops tend to be smaller and the fruit is borne lower, in between foliage of new canes. Many growers choose to forego that early crop and just enjoy the main crop of berries.
Purple raspberries and black raspberries (summer bloomers)
These raspberries are like a bush with many canes coming from one point. You will find tall, straight canes that have not bloomed and other canes with side branches where fruit was previously harvested. Cut off at ground level all canes which have had fruit, and any dead, dry canes. That leaves only canes which are straight and strong and show no evidence of old flower and fruit clusters. Cut them down to about 2 1/2 feet. They will grow fruiting side branches this year. You will be left with a massive bush. To reduce its size, remove more canes until you are left with about six of the strongest, best-looking canes of the bunch. When summer fruiting finishes on the side branches, the second-year canes can then be removed.Some cultivars include: Brandywine, Bristol, Jewel, Mac Black, and Royalty.
For tips on a variety of gardening topics, see our Plant Information Guides.
- Courtesy of NYBG Plant Information Service