Do Thornless Blackberry Bushes Spread

Thornless blackberry bushes do spread, and they can spread quite aggressively once they get established in your garden.
 
The lack of thorns doesn’t slow them down one bit when it comes to creeping across your yard.
 
So if you’ve been wondering whether thornless blackberry bushes spread, the short answer is yes, they absolutely do.
 
In this post, we’ll look at how thornless blackberry bushes spread, how far they can travel, and how to keep them under control.
 
Let’s dig in.
 

Why Thornless Blackberry Bushes Spread

Thornless blackberry bushes spread because they grow from a perennial root system that keeps sending up new canes year after year.
 
Here’s what’s really going on underground and above it.
 

1. They Spread Through Rhizomes and Suckers

The biggest reason thornless blackberry bushes spread is their root system.
 
Blackberries grow from rhizomes, which are underground stems that creep outward and pop up new shoots.
 
These new shoots are called suckers, and each one can become a whole new plant.
 
So even if you plant just one thornless blackberry bush, you can end up with a whole thicket before you know it.
 

2. Tip Rooting Sends Canes Traveling

Thornless blackberry bushes also spread by tip rooting.
 
That’s when the end of a long cane bends down, touches the soil, and grows roots right there.
 
Some thornless varieties like Triple Crown and Chester are famous for this habit.
 
So a single cane arching over can quietly plant itself a few feet away from the main bush.
 

3. They Spread Faster Than You’d Expect

Thornless blackberry bushes spread quickly because they’re vigorous growers.
 
In one season, a healthy bush can send out canes that reach 10 to 20 feet long.
 
Those canes then root, sucker, or simply sprawl into new territory.
 
The thornless trait doesn’t change any of this, so don’t expect a tamer plant just because it’s easier on your hands.
 

How Far Do Thornless Blackberry Bushes Spread?

Thornless blackberry bushes can spread several feet in every direction each year.
 
Here’s what that looks like in real terms.
 

1. Underground Spread of 3 to 6 Feet

The rhizomes and roots of thornless blackberry bushes spread roughly 3 to 6 feet from the main plant in a single growing season.
 
Over several years, that number grows fast.
 
So a bush planted near a fence or a garden bed can easily invade both.
 

2. Canes That Reach 20 Feet

The canes of thornless blackberry bushes spread even further than the roots.
 
A mature cane can stretch 10 to 20 feet if you let it.
 
When those canes tip root, your blackberry patch can double in size within a couple of seasons.
 

3. Spread Varies by Variety

Not every thornless blackberry bush spreads the same way.
 
Semi-erect types like Navaho and Apache spread less aggressively than trailing types like Black Satin.
 
So if you’re worried about thornless blackberry bushes spreading too much, choose a semi-erect variety and you’ll have an easier time.
 

How to Control Thornless Blackberry Bushes That Spread

You can keep thornless blackberry bushes from spreading with a few smart habits.
 
Here’s how to stay ahead of them.
 

1. Install a Root Barrier

A root barrier is the best way to stop thornless blackberry bushes from spreading underground.
 
Bury a sturdy plastic or metal edging at least 12 to 18 inches deep around the patch.
 
That barrier blocks the rhizomes and stops suckers from popping up on the other side.
 

2. Prune Canes Regularly

Thornless blackberry bushes spread faster when you let the canes run wild.
 
Trim the canes back to about 4 to 5 feet and tip them in summer to encourage branching instead of rooting.
 
Remove any spent floricanes after harvest so the plant puts energy into fruit, not extra growth.
 

3. Mow or Dig Up Suckers

Suckers that pop up outside your blackberry row are easy to handle if you catch them early.
 
Run a mower over them or dig them out with a spade before they establish roots.
 
If you ignore thornless blackberry bushes that spread this way, they’ll form a dense thicket in no time.
 

4. Grow Them in Containers

If you don’t want to deal with spreading at all, grow thornless blackberry bushes in large containers.
 
A 20 to 30 gallon pot with a trellis works great for semi-erect varieties.
 
That way, the plant stays put and you still get plenty of berries.
 

5. Keep the Patch Mulched and Monitored

Mulch around your thornless blackberry bushes to make suckers easier to spot and pull.
 
Walk your patch every couple of weeks during the growing season and yank anything that’s wandered out of bounds.
 
Consistency is what keeps thornless blackberry bushes from spreading into a problem.
 

So, Do Thornless Blackberry Bushes Spread?

Thornless blackberry bushes do spread, mainly through rhizomes, suckers, and tip rooting.
 
The thornless trait makes them friendlier to handle, but it doesn’t make them any less vigorous.
 
So plant them with a root barrier, prune them regularly, and stay on top of the suckers.
 
Do that, and you’ll enjoy a healthy crop of berries without letting your thornless blackberry bushes spread where you don’t want them.