Why Blackberry Keeps Coming Back After You Clear It
Updated: Sep 7
Almost everyone with land in the Fraser Valley has fought Himalayan blackberry at some point. Most people share a similar experience: you knock it down, the property looks fantastic for a season, and then it comes back—sometimes thicker than before.
This isn't bad luck or a sign that you did something wrong. It's simply how the plant is built. Himalayan blackberry has three separate ways of coming back, and cutting the canes off only addresses one of them. Let’s dive into what’s really happening beneath the surface and what it takes to finish the job.
Understanding the Challenge
Himalayan blackberry, also known as Armenian blackberry, is listed on the BC Provincial Priority Invasive Species List as a regional containment and control species. It’s not just an aggressive shrub; it’s one of the most effective colonizers we have. This plant spreads in three different ways:
The Root Crown
This is the most significant factor. Beneath every clump of canes lies a woody crown in the soil, which holds the plant's energy reserves. When you cut the canes, the crown remains untouched. It responds like any pruned plant would, pushing out new growth. According to King County's guidance, blackberry cut without further treatment can resprout from the crown at greater density than before. This explains the thicker-than-before effect that many people report.
Tip Rooting
The canes of this plant can stretch up to twelve metres long. When a first-year cane arches over and touches the soil, it can root and form a new independent plant. This is how one crown can quickly turn into a thicket that swallows a fence line in just a couple of seasons, spreading outward on its own.
Seed Production
An established thicket can produce between 7,000 to 13,000 seeds per square metre. Birds and mammals eat the fruit and distribute the seeds across your property and others. These seeds can remain viable in the soil for several years.
So, when you mow a patch, you only remove the canes. The crowns are intact, any tips that have already rooted are still there, and the seed bank remains untouched. Regrowth isn’t just a possibility; it’s a scheduled event.
Why Mowing and Brushcutting Fail
Mechanical cutting does one useful thing: it removes the top growth, allowing you to see the ground and access what truly matters. This is a valuable first step. However, it doesn’t eliminate the plant.
If you’re getting quotes for clearing, it’s crucial to understand this. A single forestry mulching pass over a blackberry field may leave you with a beautifully flat, clean-looking property. It may appear finished, but it is not. The crowns remain in the ground beneath the chip layer, and you’ll see canes again within weeks during the growing season.
Repeated cutting can work over time because it eventually exhausts the crown's reserves. But "over time" means several cuts a year for multiple consecutive years. If you take a season off, the plant will recover everything it lost. For most acreage owners, that’s not a realistic commitment.
What Actually Works: Excavation
The reliable mechanical solution is excavation. First, remove the top growth so you can see what you’re doing, then dig out the crowns and as much of the root mass as possible with a machine.
Two Honest Caveats
Incomplete Removal: It’s challenging to get all of it. Roots can get severed, and fragments left in the soil can resprout. Anyone who claims that one pass with an excavator eradicates blackberry is overselling it.
Moving Soil Moves the Problem: If you strip topsoil from a blackberry area and spread it elsewhere on your property, or bring in soil from a site that had blackberry, you’ve just planted a new infestation. The same applies to pushing debris piles into a low spot and covering them. Material from a blackberry area must be handled deliberately, not shuffled around.
When done correctly, excavation can remove the vast majority of the plant in one go, turning a multi-year battle into a manageable follow-up issue.
The Critical Year Two
Here's where most blackberry projects fail, and it has nothing to do with the machine work. Even after thorough removal, you still have a seed bank in the soil and likely a few root fragments that you didn’t get. The following spring, seedlings and resprouts will emerge. They’re small, easy to deal with, and easy to ignore.
Ignore them for one season, and you’ll find yourself back where you started. At that point, they’ll be establishing crowns of their own.
A Realistic Plan
Season One: Cut, then excavate the crowns and root mass, handling the material properly.
Season One, Later: Walk the ground and pull or spot-treat anything that comes up. This is a light job at this stage.
Season Two: Repeat the walk, but expect less work.
Season Three: By now, you’re maintaining rather than fighting.
The properties where this approach works are the ones where someone consistently walks the ground. It’s not glamorous, and it’s not expensive. It’s simply the difference between finished and unfinished.
Occupy the Ground or Something Else Will
Blackberry is a disturbance specialist. It thrives on bare, open, sunny ground, which is exactly what you have after clearing it. If you leave that ground empty, you’re creating ideal blackberry habitat, and it will find its way back.
So, the last step of blackberry removal isn’t just about removal; it’s about putting something else there. Consider planting pasture grass, a cover crop, your actual crop, a lawn, dense native shrubs, or trees that will eventually shade the area. Anything that competes with the blackberry is beneficial.
On a site that’s going to be developed, this is less of a concern since the ground will be built on. However, on an acreage you’re reclaiming, it’s the entire game.
A Note on Herbicide
Chemical control is part of the toolkit for many blackberry management programs, and it can be effective, especially on regrowth. Timing is crucial, as are the regulations. In BC, herbicide application is regulated, and some municipalities have restrictions. Additionally, there are considerations near watercourses.
This isn’t our area of expertise, and I would advise caution with anyone treating it casually. If herbicide is the right approach for your site, use a licensed applicator who can guide you on what’s appropriate for your property.
One More Thing: Blackberry Near Water
If your blackberry is along a creek, ditch, or wetland edge, and much of it is, don’t just start digging. Riparian areas have setback rules, and work near a watercourse may require approvals you don’t want to discover later. It’s a solvable problem, but it needs to be checked first.
If You're Staring at a Wall of Blackberry
Blackberry is one of the most satisfying plants to remove properly because the difference is dramatic. The land underneath is often better than people expect. However, it’s also one of the easiest things to overspend on if the first pass only takes the tops off.
If you have a thicket you’ve already cut once or twice and watched come back, or if you’re looking at a property where you can’t tell what’s under the brambles, reach out. Let us know roughly how much area you’re dealing with, how long the blackberry has been there, whether there’s water nearby, and what you want the ground to do afterward. We’ll provide an honest assessment of what it will take, including whether you can handle part of it yourself.
Call or text (604) 353-3386, email zvsoperations@gmail.com.
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