How Do You Prune Thornless Blackberry Bushes

You prune thornless blackberry bushes by removing the old canes that already produced fruit and cutting back the new ones to keep them manageable.
 
Thornless blackberry bushes still grow vigorously and need annual pruning, just like their thorny cousins, because without it they turn into a tangled mess.
 
The good news is that pruning thornless blackberry bushes is actually easier since you don’t have to fight thorns while you work.
 
In this post, we’ll walk through exactly how to prune thornless blackberry bushes, when to do it, and the simple steps to keep your plants healthy and productive.
 
Let’s dig in.
 

How Do You Prune Thornless Blackberry Bushes?

You prune thornless blackberry bushes by focusing on two main things: removing the canes that already fruited and thinning out the new canes for next year.
 
The reason is simple.
 
Thornless blackberry bushes produce fruit on second-year canes, which are called floricanes.
 
Once a floricane finishes fruiting, it will never produce berries again.
 
So if you leave it in place, it just takes up space, blocks sunlight, and invites disease.
 
Here’s how to approach pruning thornless blackberry bushes step by step.
 

1. Remove the Old Fruiting Canes

Right after harvest, cut the canes that just produced berries all the way down to the ground.
 
These floricanes are spent and won’t give you anything next season.
 
Use clean, sharp pruning shears and make your cuts as close to the soil line as possible.
 
This is the most important part of pruning thornless blackberry bushes because it clears the way for new growth.
 

2. Thin Out the New Canes

The new canes that grew this year are called primocanes, and they’ll fruit next season.
 
You don’t want to keep every single one because overcrowding leads to poor airflow and smaller berries.
 
When pruning thornless blackberry bushes, aim to leave about four to six strong, healthy canes per plant.
 
Cut the rest back to the ground.
 
Choose canes that are thick, upright, and evenly spaced.
 

3. Trim the Canes to a Manageable Height

Once you’ve selected your keepers, tip them back to around four to five feet tall.
 
This encourages side branching, which is where the fruit actually forms.
 
If you’re growing trailing varieties of thornless blackberry bushes, you can let them grow a bit longer and train them along a trellis.
 
For upright types, keeping them shorter makes harvesting much easier.
 

4. Clean Up All Debris

After pruning thornless blackberry bushes, gather every cane, leaf, and berry you removed.
 
Don’t leave them lying around the base of the plant.
 
Old plant material can harbor pests and fungal diseases that will cause problems next season.
 
Either burn the debris or bag it and toss it in the trash.
 

When Is the Best Time to Prune Thornless Blackberry Bushes?

The best time to prune thornless blackberry bushes is in late summer right after you finish harvesting, usually around July or August depending on your climate.
 
That’s when you remove the spent floricanes and thin the new growth.
 
You can also do a light cleanup in late winter or early spring before new growth starts.
 
At that point, just remove any canes that died over the winter or look weak and damaged.
 
Avoid heavy pruning thornless blackberry bushes in the middle of winter when the plants are fully dormant because you might remove canes that would have fruited.
 
Timing really matters if you want a good harvest.
 

1. Summer Pruning After Harvest

This is your main pruning session.
 
Cut out the old canes and thin the new ones right after the berries are done.
 
This gives the plant time to recover before winter and directs energy into the canes that will fruit next year.
 

2. Late Winter Touch-Ups

A quick pass in late winter helps you spot dead or broken canes easily since there are no leaves in the way.
 
Just don’t go overboard.
 
Light maintenance is all you need during this window.
 

Tools and Tips for Pruning Thornless Blackberry Bushes

Having the right tools makes pruning thornless blackberry bushes faster and safer.
 
Here’s what you’ll want on hand.
 

1. Sharp Bypass Pruners

A good pair of bypass pruners handles most of the work.
 
Keep them sharp and clean to make smooth cuts that heal quickly.
 
Dull blades crush the canes and open the door to disease.
 

2. Loppers for Thick Canes

Some canes on mature thornless blackberry bushes get thick.
 
Loppers give you extra leverage for those tougher cuts.
 
You’ll save your hands a lot of stress.
 

3. Gloves and Safety Glasses

Even though thornless blackberry bushes don’t have thorns, the canes can still be tough and whippy.
 
Gloves protect your hands, and glasses keep debris out of your eyes.
 

4. Disinfect Your Tools Between Plants

Wipe your blades with rubbing alcohol before moving to the next plant.
 
This small habit prevents spreading disease from one thornless blackberry bush to another.
 

So, How Do You Prune Thornless Blackberry Bushes?

You prune thornless blackberry bushes by cutting out the old fruiting canes and thinning the new ones to four to six strong canes per plant.
 
Do it right after harvest in late summer, clean up all the debris, and use sharp, clean tools.
 
The process is straightforward, and because these bushes have no thorns, it’s a lot more enjoyable than pruning other brambles.
 
Stay consistent with pruning thornless blackberry bushes each year and you’ll be rewarded with bigger, sweeter berries and healthier plants season after season.