SBK: The Brushwood Killer and Its Various Uses

Hi, Dave here from Foxy Gardens in southwestern Ontario.  If you’ve been battling stubborn weeds like brambles, nettles, and tree saplings in your yard, there’s a good chance you’ve heard of SBK the Brushwood Killer.

This powerful, selective herbicide is a go-to solution for homeowners and landscapers alike who want to control woody weeds without damaging surrounding grass or plants.

In this article, we’ll explore what SBK is, how it works, its various applications, and why it’s a practical solution for difficult-to-remove vegetation—especially in places like Ontario, where invasive plants and persistent brush can quickly take over.

What Is SBK the Brushwood Killer?

SBK stands for “Selective Brushwood Killer.” It is a herbicide designed to kill tough, woody plants right down to the root system. Unlike general-purpose weed killers that often burn the foliage without reaching the roots, SBK contains triclopyr, a systemic herbicide that is absorbed through the leaves and travels internally through the plant.

This makes it particularly effective against:

• Brambles and blackberry bushes

• Nettles

• Ivy

• Tree stumps

• Saplings and small trees

• Dock and thistle

• Horsetail (with proper preparation)

Its selectivity means it typically won’t harm your lawn, making it ideal for targeted applications around grass margins, paths, fences, and open gardens.

How SBK Works

SBK Brushwood Killer works by mimicking plant growth hormones. When absorbed, it causes uncontrolled cell growth in the plant tissues, which leads to wilting, yellowing, and ultimately the death of the plant.

The active ingredient, triclopyr, is especially effective at targeting broadleaf and woody species without affecting most grasses.

It’s important to note that SBK is not a contact herbicide. It won’t work overnight, but over several weeks, it disrupts the plant’s internal systems so that regrowth is prevented.

Key Uses of SBK the Brushwood Killer

Here are the most common and effective ways to use SBK in gardens and outdoor spaces:

1. Killing Brambles and Woody Brush

Brambles are notorious for their fast growth and tough root systems. SBK is specifically made to handle these kinds of stubborn invaders. Apply during the active growing season (usually late spring to early fall) for best results.

Use a sprayer or watering can to coat the leaves thoroughly. In about 3–4 weeks, you’ll notice significant dieback, and regrowth is minimized.

2. Treating Tree Stumps

One of SBK’s standout features is its ability to kill tree stumps and prevent them from re-sprouting. This is particularly useful for invasive species or trees growing too close to structures.

To use:

• Cut the tree down as close to the ground as possible.

• Immediately apply a 50:50 mixture of SBK and water to the freshly cut surface using a brush or sprayer.

• Apply during the dormant season (late fall to early winter) for best results.

This method is often called the cut-stump treatment and is commonly used in both residential and rural Ontario settings to control spread without uprooting.

3. Controlling Ivy and Creeping Vines

Ivy can strangle trees, fences, and buildings. SBK can be sprayed onto the leaves and stems to control overgrowth. For tough vines like poison ivy, multiple treatments may be needed, especially if the plant has a waxy surface.

Tip: Lightly damaging the surface of the leaves before spraying can help the herbicide penetrate better.

4. Dealing with Invasive Horsetail

Horsetail (Equisetum) is a nightmare for many Ontario gardeners because of its deep rhizome network and waxy coating. While no herbicide can offer a guaranteed kill in one go, SBK is one of the more effective options.

To maximize results:

• Crush or damage the plant surface with a roller or rake.

• Add a surfactant or wetter like soap or a branded additive (e.g., KPlus+) to improve absorption.

• Apply SBK on a dry day during active growth.

You may need to re-treat throughout the season, but SBK gives you a fighting chance against this prehistoric pest.

When to Apply SBK for Best Results

Timing is crucial for SBK to be effective.

Avoid applying SBK during periods of drought, freezing temperatures, or heavy rain. You want the plant to be actively growing so it draws the herbicide deep into the root.

How to Apply SBK Brushwood Killer

• Mix according to label instructions (typically 25–30 ml per litre of water).

• Use a watering can with a rose or a hand sprayer for even distribution.

• Avoid drift—SBK can harm desirable broadleaf plants if it reaches them.

• Keep pets and children away from treated areas until dry.

You can buy SBK in different sizes depending on your needs, with 250 ml, 500 ml, and 1-litre bottles being common.

Is SBK Safe?

SBK is safe for home garden use when used as directed. However:

• Always wear gloves and eye protection.

• Don’t use near ponds or water features.

• Do not compost treated plants.

• Keep away from edible crops and fruit trees.

Once dried, the treated area is generally safe for pets and humans to walk through, although it’s best to wait a few hours.

Is SBK Legal and Available in Ontario?

As of writing, SBK is not widely sold in Canada, including Ontario, due to the province’s strict cosmetic pesticide regulations. While triclopyr products are used in forestry and industrial weed control, consumer options are limited or regulated.

If you’re in Ontario and considering importing SBK or using similar products, check with:

• Ontario Ministry of the Environment

• Municipal bylaws

• Integrated Pest Management (IPM) alternatives

For legal alternatives, you may need to consult a licensed pesticide applicator or look into vinegar-based or iron-based selective herbicides approved for home use.

Final Thoughts

SBK the Brushwood Killer is a powerful and reliable option for controlling invasive and woody weeds in your garden or rural property. Its versatility—from killing brambles to halting stump regrowth—makes it a favorite in the UK and other regions. Though it may not be as readily available in Ontario due to regulations, it remains an important benchmark for what a good brushwood herbicide can achieve.

If you’re battling deep-rooted weeds and looking for a selective herbicide that won’t wreck your lawn, SBK (or a Canadian-approved alternative with triclopyr) could be the solution you need.