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Blackberry Pruning Demystified

RachelThis year we got a rather large number of free blackberry canes given to us from our lovely next door neighbors that were moving. My husband Matt and his friend dug them up and planted them in their new location early this spring. While all bramble fruit seem pretty no muss no fuss, they actually do require some tender loving twice a year. They will continue to fruit and reproduce without pruning of course, but they won't be nearly as vibrant from season to season if you don't devote just a little time to them. These pruning methods can be applied to raspberries, too, since the plants' growing habits are the same.

There are several kinds of blackberry plants that behave in all sorts of different ways. The three main types are Erect, Trailing, and Thorn-less. It helps to know what type you have when it comes to trellising the canes. I happen to have erect blackberries, they have tall arching canes and I do not trellis them. I find that they do just fine without it for our circumstances, though perhaps in the future it would be nice to do an upgrade. No matter the type you have, they all like to be pruned in the same manner. Pruning has many benefits including helping ward off diseases, larger berries, and higher yield.

Before we get started you might want to consider purchasing a pair of kevlar sleeves, I was given a pair and I love them. They save your arms from getting cut and scraped by those nasty thorns when you are working with them, whether pruning or picking, and if you have a big berry patch they can really save you from looking like you got beat up by that cranky old barn cat.

Blackberry canes are “biennial” meaning that the canes live for two years. In nearly all varieties first year canes will not bear fruit and are called “primocanes”; they are easy to spot because they are nice and green. In the spring you will want to tip prune the first few inches from the primocanes when they are shorter than 3 feet tall. This makes the primocane grow a thicker stem that will support a larger fruit load next year, and grow more lateral branches where more berries will grow. You will notice in the fall that the primocanes will have grown their thin brown bark in preparation for the winter and next year
Blackberry primocane
Blackberry primocane

Some varieties of blackberries send runners or “suckers” off a few feet away from the patch. If the suckers look nice, we like to dig them up and plant them back in the row. Its a nice free way to expand our patch. Suckers are primocanes.
Blackberry sucker
Suckers will pop up around 2 to 3 feet from your blackberry patch.

The current year's fruiting canes are called “floricanes”. Besides blossoming and bearing fruit these canes can be identified by their thin brown bark. After their fruit ripens the leaves on these canes start to fizzle out. In the winter trim the spent floricanes back to the crown. In winter when there are no leaves and the brand new floricanes for the coming season look the same at first glance as last year's dead floricanes, pruning can be a little tricky. Last year's spent floricanes will look brown while new floricanes will have a purplish tint when compared with each other. Another way to tell them apart is to look for the remnants of last years fruiting blooms. And if that isn't quite enough to make you certain you are about to chop the right cane, you can take your clippers and scrape a teeny bit of bark off. If it is green underneath the bark you have a new cane, if its brown you have a dead cane that needs to be pruned. Getting rid of the spent canes in the winter before fruiting helps the plant to focus nutrients on the new floricanes.
Blackberry floricane
Current year floricanes.

Dead Floricane

A spent floricane in need of pruning. Notice the thin stems with buds on the ends.

When you are finished pruning the spent floricanes be sure to collect them all and burn them or have them hauled away. Be sure to wash your clippers too. Do not try to compost them as they could possibly spread disease. Blackberries and raspberries are notorious for contracting all sorts of fungal diseases. Better safe than sorry. Seriously how simple was that? Just a little work for bigger and better berries!