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You can prune thornless blackberries in late winter or early spring while the plants are still dormant.
The best time to prune thornless blackberries is usually February or early March, just before new growth begins.
If you prune too early in winter, cold damage can hurt the fresh cuts.
If you prune too late, you may accidentally remove the new canes that will produce fruit.
That’s why timing matters so much when you prune thornless blackberries.
In this post, we’ll walk through how and when to prune thornless blackberries, the tools you need, and the simple steps to keep your plants healthy and productive.
Let’s get started.
When to Prune Thornless Blackberries
Knowing when to prune thornless blackberries makes all the difference between a weak harvest and a bumper crop.
Here’s how to time it right.
1. Late Winter Is the Sweet Spot
The ideal window to prune thornless blackberries is late winter, when the plants are dormant but the worst cold has passed.
In most regions, that means February through early March.
At this stage, the canes are resting, and pruning won’t shock the plant.
You also get a clear view of the structure since there are no leaves in the way.
2. Avoid Pruning in Freezing Temperatures
Don’t prune thornless blackberries when temperatures are below freezing.
Fresh cuts are vulnerable to freeze damage and can die back.
Wait for a mild day when the forecast looks stable.
If you prune thornless blackberries too early, you risk losing healthy canes to winter injury.
3. Prune After the Last Severe Frost
A good rule is to prune thornless blackberries after the last severe frost but before buds break.
That’s when the plant is still dormant but ready to grow.
If you wait until you see green tips, you’re cutting it close.
Pruning thornless blackberries at the right moment sets up strong spring growth.
4. Summer Pruning for Tips
You can also lightly prune thornless blackberries in summer to control size.
This is called tipping, where you cut the tips of new canes to encourage branching.
Just don’t do heavy pruning in summer, as it can stress the plant.
Light summer pruning of thornless blackberries helps keep them manageable.
How to Prune Thornless Blackberries
Now that you know when, let’s talk about how to prune thornless blackberries step by step.
The process is simple once you understand the plant’s growth cycle.
1. Remove Dead and Damaged Canes
Start by cutting out any dead, broken, or diseased canes.
These won’t produce fruit and can harbor pests or disease.
Cut them at the base, close to the ground.
When you prune thornless blackberries, always remove the weak canes first.
2. Cut Out Old Fruiting Canes
Thornless blackberries produce fruit on second-year canes, called floricanes.
After they finish fruiting, those canes die and won’t produce again.
So when you prune thornless blackberries, cut out the old floricanes entirely.
This makes room for new canes, called primocanes, to grow and fruit next year.
3. Thin the New Canes
Keep only the strongest, healthiest new canes.
A good rule is to leave about 5 to 8 canes per plant.
Space them out so air can flow freely.
When you prune thornless blackberries, thinning prevents overcrowding and disease.
4. Trim Side Branches
Cut side branches back to about 12 to 18 inches.
This encourages more fruit-producing laterals.
Shortening these branches also keeps the plant from getting top-heavy.
If you prune thornless blackberries properly, you’ll get more berries per cane.
5. Tie Canes to a Trellis
After pruning, secure the remaining canes to a trellis or wire system.
This keeps them upright and makes harvesting easier.
Tying also improves air circulation around the plant.
When you prune thornless blackberries and train them, you set up a cleaner, more productive patch.
Tools and Tips for Pruning Thornless Blackberries
Having the right tools makes the job easier and safer.
Here’s what you need and a few tips to keep in mind.
1. Use Sharp Bypass Pruners
Sharp bypass pruners give clean cuts that heal faster.
Dull tools crush the canes and invite disease.
Clean your pruners with rubbing alcohol before and after use.
When you prune thornless blackberries, clean cuts are your best friend.
2. Wear Gloves and Eye Protection
Even though thornless blackberries have no thorns, the canes can still scratch.
Wear gloves to protect your hands and glasses to protect your eyes.
Safety first, always.
3. Dispose of Cuttings Properly
Don’t leave diseased canes on the ground.
Burn them or bag them for trash pickup.
This prevents pests and disease from spreading back to your plants.
After you prune thornless blackberries, clean up the area well.
4. Don’t Over-Prune
It’s tempting to cut everything back, but don’t.
Removing too much can stress the plant and reduce next year’s crop.
Stick to removing only dead, old, and weak canes.
When you prune thornless blackberries, moderation is key.
So, How and When to Prune Thornless Blackberries?
You prune thornless blackberries in late winter or early spring while they’re dormant, and you do it by removing dead canes, cutting out old floricanes, thinning new growth, and trimming side branches.
Timing it right avoids cold damage and protects new growth.
Doing it correctly keeps your plants healthy and your harvest heavy.
Now you know exactly how and when to prune thornless blackberries, so grab your pruners and get ready for a great season.