How to prune raspberries

In order to correctly prune raspberries or blackberries or any of their many hybrids it is important to understand their basic growth habit as well as what you want to get from them. 

If you don’t understand their growth you will never get the full potential from them.  If you don’t know what you want from them you are wasting your time in pruning them at all.

Floricane blackberry will not fruit well if pruned like this

Established brambleberries grow from a crown, each year they put up new growth, this new growth is referred to as a primocane.  The primo part of this word means 'first' as they are first year growth.

After the growing season is over the primocane will sit over winter and not do a great deal that you can see, the following season this older growth is referred to as a floricane.  Floricanes were originally the only canes that flowered, but we have since bred some varieties that can flower on their primocanes.   Knowing about floricane and primocane is important so you can prune them properly.

Raspberries

Primocane vs Floricane
All brambleberries can be roughly divided into two artificially imposed and sometimes slightly overlapping groups.  One group can only flower and fruit on old growth, we call them floricane (or summer fruiting)  The other group can flower and fruit on new growth, we call them primocane (or autumn fruiting or everbearing).  It is important to which about them as the way each group can be pruned can be slightly different.

All brambleberries have the ability to flower and fruit on a floricane, or second year growth.   This is how most of the wild brambleberries work.  Most varieties of cultivated brambleberries will only ever flower and fruit on floricanes.  This means if you prune your plant to the ground each winter, or if animals get in and damage the canes, the plants will be nice and healthy but you will never get any fruit.

My golden raspberries are floricane flowering

Pruning Floricane Raspberries
Most people prune floricane varieties by leaving new growth and cutting out canes that have fruited the previous year. They also cut out the tip growth to encourage branching which means they produce more flowers.  It can be difficult to know which canes are which and there is extra time and care required to prune them.   Some people put tape or something around a cane that has fruited to show that it should be pruned out in winter, this takes time and effort.

Some canes die after fruiting, others will fruit again the following year.  Some people only prune in spring when the plants are breaking dormancy by removing any dead canes.  Again, it takes a little time and effort to achieve this.

One benefit of floricane varieties is that there are a lot of varieties to choose from, some do better in different climates and some fruit earlier or later than others.  Don’t ever buy an un-named variety, accept them if they are free, but don’t buy them.

Some brambleberries fruit on floricanes as mentioned above, but they also flower and fruit on first year growth, these varieties are referred to as primocane.  There are several ways to prune primocane varieties, there are benefits to each way.

Dormant raspberries, these are thornless primocane

How to prune Primocane raspberries to get one crop per year
The way that most people are encouraged to prune primocane varieties is each winter to cut it to the ground, this can be done quickly and easily if you run over the plant with the lawnmower.   The results are that the plant will throw up new growth in spring and fruit late summer/early autumn.

Many commercial producers prune in this way, it is fast, it is simple, and it is cost effective.  Different varieties fruit earlier or later so you can extend your harvest by planting a few named varieties.   Instead of the lawnmower you could carefully cut out each cane and use it as a cutting to grow more plants.   You have options depending on how much time and effort you have to spend on them.


How to prune Primocane raspberries for two crops per year
Another way to prune primocane varieties is to treat them as if they were floricanes.  Each year don’t cut them to the ground, instead leave that growth to flower and fruit next year.   Only remove dead canes, and possibly remove the tips of the floricanes.  Removing the tips encourages the plant to branch, thus producing more flowers and more fruit.  The plant still puts up new growth in spring, it still flowers and fruits on this new growth in autumn, but it will also produce an earlier crop on each of the floricanes.

Pruning like this gives you a second crop, an early crop from the floricanes and a late crop from the primocanes.  I have heard gardeners say that removing the floricanes helps the plant produce a larger crop on the primocanes, this seems logical enough, unfortunately every study I have seen on this tends to indicate this is not the case.

Brambleberries store a lot of energy in the roots, getting two crops each year does not appear to decrease the primocane crop in any way.

Thornless raspberries

Can you get a second crop from a floricane variety
I mentioned earlier that there is some overlap between floricane varieties and primocane varieties, this is where things get interesting.  I currently grow a thornless raspberry that is referred to as a floricane variety.  It usually only produces one large crop in summer on old growth.  Sometimes it will produce also produce a small autumn crop on each of the primocanes.  This second crop is not guaranteed, and is usually based on the weather, but it is still a primocane crop from a floricane variety.

Just like above, I prune them as if they are floricane, otherwise there is a chance that I will not get any crop from them that year.

There are a lot more floricane varieties than primocane varieties, this is simply because they are more prevalent in the wild and it took us a while to find good primocane varieties and breed from them.  I grow both primocane and floricane raspberry varieties, but I prune them both as if they were floricane and sometimes get two crops from both. 
 

Raspberry plants for sale in Australia
I grow several different varieties, some are thornless, some are primocane flowering, one is a thornless floricane that sometimes fruits on its primocanes, I even sell a yellow fruiting golden raspberry.  I sometimes sell raspberry canes on my for sale page over winter when they are dormant.