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Trellising thornless blackberries is one of the smartest things you can do to keep your plants healthy, productive, and easy to manage.
If you’ve been wondering how to trellis thornless blackberries, the good news is that it’s simpler than you might think.
Thornless blackberries still grow long, sprawling canes, and without support, those canes end up tangled on the ground, which invites disease and makes harvesting a chore.
A proper trellis keeps your thornless blackberries upright, improves airflow, and makes picking baskets of fruit way more enjoyable.
In this post, we’ll walk through how to trellis thornless blackberries step by step, including the best trellis types, when to set them up, and how to train the canes properly.
Let’s dig in.
How to Trellis Thornless Blackberries: The Basics
Trellising thornless blackberries starts with understanding how these plants grow.
Thornless blackberries produce two types of canes: primocanes and floricanes.
Primocanes are the first-year canes that grow vegetatively, while floricanes are second-year canes that produce fruit.
Knowing the difference matters because how you trellis thornless blackberries depends on which canes you’re dealing with.
Most thornless blackberry varieties are trailing or semi-erect, which means they really do need a trellis to thrive.
1. Choose the Right Trellis Type
The best trellis for thornless blackberries is usually a T-trellis or a two-wire trellis system.
A T-trellis uses a sturdy post with a horizontal crossbar at the top, and you run wires along each side.
This design works beautifully for thornless blackberries because it lets you spread the canes out and keep them separated.
A simple two-wire trellis with wires at roughly 3 feet and 5 feet high also does the job for many home gardeners.
2. Pick the Right Location
Before you trellis thornless blackberries, pick a spot with full sun and good drainage.
Thornless blackberries love at least six to eight hours of sunlight daily.
The trellis should run north to south if possible, so both sides of the plants get even light.
Good airflow around your trellised thornless blackberries also cuts down on fungal problems.
3. Set Posts and Wires Properly
Use sturdy posts that are at least 6 to 8 feet long and sink them about 2 feet into the ground.
Space your posts roughly 10 to 15 feet apart, depending on how many thornless blackberries you’re growing.
Run high-tensile wire between the posts and tighten it well, because sagging wires won’t hold your canes.
For a T-trellis, attach the crossbar at the top and run wires along both sides to support the canes.
How to Train Thornless Blackberries on a Trellis
Once your trellis is up, training your thornless blackberries is where the real work begins.
You can’t just build it and walk away, because thornless blackberries need guidance as they grow.
1. Train Primocanes First
During the first growing season, let your primocanes grow and gently guide them toward the trellis.
As the canes of your thornless blackberries get long enough, tie them loosely to the wires.
Use soft ties or twine so you don’t damage the canes.
Spread them out rather than bunching them together so air can move freely.
2. Separate Floricanes for Fruiting
In the second year, your floricanes are the ones that will fruit.
Train these fruiting canes along the wires where they get maximum sun exposure.
Keep them separate from the new primocanes, so you always know which canes to prune later.
This separation is a big reason why learning how to trellis thornless blackberries correctly pays off.
3. Prune After Harvest
After your thornless blackberries finish fruiting, cut the old floricanes back to the ground.
This clears space for the new primocanes to take over next season.
Pruning keeps your trellised thornless blackberries from becoming a tangled mess.
It also reduces pest and disease pressure year after year.
Common Mistakes When You Trellis Thornless Blackberries
Even with good intentions, gardeners often make a few mistakes when they trellis thornless blackberries.
1. Using Weak Posts
Thornless blackberries get heavy once they’re loaded with fruit.
Flismy posts will lean or snap under the weight, so go sturdy from day one.
2. Crowding the Canes
Packing canes too tightly defeats the purpose of trellising thornless blackberries.
Crowded canes trap moisture and encourage rot and fungal disease.
3. Skipping Winter Care
In colder zones, thornless blackberries may need their canes laid down and covered for winter.
A flexible trellis system makes this much easier to manage.
4. Forgetting to Tie New Growth
New canes grow fast, so check your thornless blackberries every week or two during the growing season.
Tying them early keeps them from flopping over and breaking.
So, How Do You Trellis Thornless Blackberries?
You trellis thornless blackberries by building a sturdy T-trellis or two-wire system, training primocanes and floricanes separately, and pruning old canes after harvest.
Thornless blackberries reward you with cleaner fruit, better airflow, and easier picking when they’re properly supported.
A little planning upfront makes trellising thornless blackberries a breeze, and your plants will thank you with bigger harvests season after season.
Now you know exactly how to trellis thornless blackberries and keep them thriving for years.