Getting rid of blackberry bushes permanently requires cutting, digging the root crowns, and following up with persistent smothering or targeted spot herbicide application on regrowth.
A single blackberry patch can turn into a thicket fast. The canes root where they touch the ground, and root crowns send up new shoots for years. The goal is to starve the root system so it stops coming back. Here is the working sequence, from first cut to the point you can replant.
Why Blackberry Bushes Are So Hard To Kill
The root crown — a thick woody mass just below the soil surface — stores energy and holds dormant buds. Cut the canes and the crown sends up new canes within weeks. Even a root fragment can grow into a new plant. Oregon State Extension emphasizes that removal requires persistence and planning because the plant is biologically designed to survive everything short of total root removal or properly timed herbicide application.
The Mechanical Removal That Actually Works
Start on a dry day when soil is firm. Wear heavy leather gloves, long sleeves, and eye protection — thorns can puncture thin garden gloves and cause infections.
- Cut every cane to ground level. Use loppers or a brush cutter for thick basal canes. Lay cut canes on a tarp — do not leave them on bare soil because tips can root.
- Dig around the root crown. Use a sharp spade or mattock to cut a circle about 12 inches around the crown, then pry the whole mass out. Remove as much root material as possible.
- Repeat digging in six weeks. New shoots will emerge from missed fragments. Cut and dig again each time to drain energy from remaining root pieces.
For large patches, Oregon State Extension recommends mowing repeatedly or grazing with goats. Neither eradicates roots completely, but both weaken the patch over time.
Smothering and Herbicide: Two Ways To Finish The Job
Smothering. Cover the cleared area with thick black plastic or heavy-duty landscaping fabric. Secure edges and leave for at least one full growing season. Some sources recommend adding a 4-inch mulch or cardboard layer under the plastic. Downside: you cannot plant there until the plastic comes off, and persistent root crowns can push shoots at edges.
Herbicide. When digging and smothering are not enough, targeted herbicide is the most reliable way to kill deep-rooted remnants. Triclopyr is effective on green foliage; glyphosate is effective in late summer to early fall when the plant pulls energy into roots. Trimec works for smaller patches. The cut-stump method — cut the cane and apply herbicide directly to the fresh stump — works well in fall or winter. Oregon State Extension notes that timing matters: spraying on a windy day, before rain, or during drought reduces effectiveness and increases drift risk.
Common Mistakes That Let Blackberries Come Back
- Leaving cut canes on the ground. They can root at the tips. Bag them or cart them off-site.
- Not digging enough root crown. A fist-sized crown can send up 20 new canes. Plan to cut regrowth every 3–4 weeks if you cannot get the whole thing.
- Spraying on a windy day or before rain. Herbicide drifts or washes off. Check the label for a rain-free window.
- Applying glyphosate to drought-stressed plants. The plant cannot transport the chemical effectively. Wait for a healthy growth flush after rain.
Once blackberry is gone, replant with competitive grasses or fast-growing perennials. Oregon State Extension recommends this because dense ground cover reduces the chance that dormant blackberry seeds will germinate.
FAQs
Can goats really clear blackberry bushes?
Yes. Goats eat canes and foliage and can clear large patches over time. They do not remove root crowns, so regrowth is likely, but grazing weakens the patch significantly and works on steep or rocky ground.
Will digging remove blackberries forever?
Not in one pass. Even when you remove the main crown, small root fragments can resprout. Persistent digging and cutting over one to two seasons permanently exhausts the root system.
Is it safe to use herbicide near other plants?
Triclopyr can damage broadleaf ornamentals; glyphosate kills any green plant it touches. Shield desirable plants with cardboard or plastic during spraying, and only apply on calm days.
References & Sources
- Oregon State University Extension. “Tackling invasive Himalayan blackberry takes persistence, planning.” Core source for mechanical removal steps, timing, and persistence requirement.
- Oregon State Extension Ask an Expert. “How to permanently get rid of blackberry bushes.” Details on digging depth, crown removal, and smothering methods.
- Northwest Center for Alternatives to Pesticides. “Blackberries: A Management Guide.” Herbicide options and safety considerations for blackberry control.