Spring will come, although not soon enough for cabin-fevered gardeners. In late winter, take advantage of a mild day to do raspberry maintenance. Here's how to prune red, gold, purple or black raspberries, and clean up your raspberry jungle in preparation for this year's delicious crop.Supplies you'll need
- hand pruners
- gloves that withstand raspberry stickers
- leaf rake
- hand cultivating or weeding tool
- organic mulch, a generous amount
Drop the wires or support system, if you have one. This gives you easier access to the work zone. If you have no raspberry trellis, you can receive guidance from the article, " Okay, so you have raspberries, blackberries or other brambles... How do you control them? With a Bramble Trellis! " by Darius Van d'Rhys.Understanding raspberries helps you make sense of pruning them
First you should know a bit about berry biology. A raspberry cane designed by Mother Nature is like a biennial plant. A new cane grows up from the ground for a year. In its second summer, it blooms from the top down and has fruit. That's the way summer bearing, old fashioned red raspberries grow, and how purple and black raspberries grow. After the fruit is picked in the second year, you'll see tall canes with old dried clusters of fruitless cores, like in the picture above. Those canes usually die soon.
Newer cultivars of red, and gold, raspberries developed by Father Agriculture now cheat that two-year cycle. These everbearing or fall-bearing raspberries will produce new canes each year which start to bloom and fruit the same year in the fall. They bloom first on the tip of the cane. Then from the top down, they bloom on side shoots originating at each leaf on the main stem. These canes survive the winter and you can see the skeletons of old fruit on them. The following spring, fruiting side shoots continue to appear from the point at which they stopped when winter hit. Those canes will be finished a few weeks later and will not produce any more berries. Everbearing raspberries can also be managed to provide just one main crop each year.
Black raspberries grow in a bushier form, and purple raspberries are a black-red hybrids which also grow as a bush.
Different raspberry types have different pruning needs. In raspberry culture, there are three basic categories of raspberry:
- Red standard, summer bearing (floricane)
- Red, and gold, everbearing (fall-bearing, primocane)
- Purple raspberries and black raspberries
Find the type you own in the table below and follow the instructions. If you have no idea what kind of raspberries you're growing, skip to the last section of the table.
Red summer-bearing raspberries (also called floricane fruiting)
Some cultivars: Boyne, Canby, Citadel, Encore, Killarney, Latham, Liberty, Nova, Prelude, Reveille, Taylor, Titan
You'll find tall straight canes that have not bloomed and other canes with clusters of side branches where fruit was picked. Cut to the ground all canes which have had fruit, and remove any brittle, dead wood. You're left with the first-year canes which are straight and show no evidence of old flower and fruit clusters. These canes will bear fruit from the top down in their second summer. However, if there are too many canes close together you won't get the best quality fruit. Now you cut the skinniest of them if needed, so that no two canes are closer to each other than about six inches. Also remove any little spindly crooked sprouts. They are runts that won't be productive.
To maintain: Prune fruited canes as soon as you finish picking berries from them.
Red everbearing raspberries, (also called fall-bearing or primocane fruiting, and includes gold, which are just a variation of red)
Some cultivars: Amber, Autumn Bliss, Autumn Britten, Caroline, Fall Gold, Fall Red, Goldie, Heritage, Jaclyn, Redwing, Ruby
Two-crop method: 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 the ground. Remove any dead wood. Now thin out the canes you have left, by taking out the smallest and leaving at least six inches between canes. Also remove any weak scrawny sprouts or dead wood.
To maintain: As soon as the older canes bear fruit early this summer, they can be cut out, leaving space for the new canes.
One-crop method: Cut all of the canes now. You can even mow the area. Why do this? The main crop of raspberries is in the fall. This is when you'll get your 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. This method makes pruning a lot quicker and easier.
Purple raspberries and black raspberries
Some cultivars: Brandywine, Bristol, Jewel, Mac Black, Royalty
These raspberries are like a bush with many canes coming from one point. You have tall straight canes that have not bloomed and other canes with side branches where fruit was picked. Cut off at ground level all canes which have had fruit, and any dead, dry canes. You're left with the canes which are straight and strong and show no evidence of old flower and fruit clusters. Cut them down to about two and a half feet. They will grow fruiting side branches this year. Now if you're still left with a massive bush, remove more canes until you are left with about six of the strongest, best looking canes.
To maintain: Remove canes as they finish fruiting on side branches.
"I have no idea what kind they are" raspberries
You inherited a raspberry jungle and have no idea what kind they are? Prune out all canes which have evidence of old fruit sprays. Thin (cut off extras at the ground) the rest of canes to leave six inches between them. Observe the raspberries during the next growing season and maybe you can determine which type you have.
If you've navigated that table of pruning you've finished the hard part of the job. Use the leaf rake to rake out pieces of cane and leaves from the berry bed. Take all the cut canes and debris away to dispose of it by burning or bagging.
Edge the bed
Keep the raspberry row 24 inches wide or less, for good air circulation and picking ease. Dig out sprouts coming up outside the boundary of the bed.
Now that the jungly overgrowth is gone, you can weed the berry bed by hand or with gentle cultivation. Remember, those red raspberry plants have shallow roots which produce replacement canes.
Raspberries like an organic soil. Apply a generous layer (up to eight inches) of organic mulch like straw, compost, or aged manure. This mulch will keep new weed seeds from sprouting, and will enrich and cool the soil during the growing season. Don't use a weed blocker on red raspberries; they need to make new canes from underground roots throughout the bed.
Step back and stretch
At this point, step back, take a well deserved stretch and admire your airy, neat, fertile looking mulched raspberry bed. Put away the garden tools; your next task in this bed will only require a cereal bowl.
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University of Kentucky, Jones, R. T. and J. G. Strang, Growing Raspberries and Blackberries in Kentucky
Cornell University, Cornell Fruit Resources, Berries
Photo creditsThanks to Lee Anne Stark for the use of the raspberry picture above, and to Dave's Garden Admin Melody for photo advice. Other pictures taken by and property of the author. PlantFilesRead Dave's Gardener comments on many of the abovementioned varieties here in PlantFiles (Editor's Note: This article was originally published on February 21, 2009. Your comments are welcome, but please be aware that authors of previously published articles may not be able to respond to your questions.)