Triclopyr Weed Killer


Triclopyr Weed Killer: The Best Solution for Tough Weeds?

You've tried them all! Every weed killer you've used hasn't had any affect on your tough weeds but have you tried Triclopyr? This tough weed killer is ranked amongst the strongest you can buy.

Developed in the 1970's, it is widely approved across the world (although it is restricted for professionals in certain countries) for a variety of situations:

Triclopyr is widely used to control a wide variety of tough weeds. It's a selective weed killer that is also used in lawns as it doesn't effectively kill grass (unless used in really high doses). Triclopyr is commonly used to control Brambles, Thistles, Docks, Nettles & to a lesser degree Ivy.

Which is better Glyphosate or Triclopyr?

It depends on the application and weed species - different strokes for different folks!

Glyphosate is a non-selective herbicide, meaning it will kill all plants that it comes into contact with. Triclopyr is a selective herbicide, meaning it will only kill certain plant species.

For example, glyphosate would be better for killing weeds in a garden, while triclopyr would be better for killing weeds in a lawn or near grass you want to keep.

Triclopyr vs Glyphosate: Advantages & Disadvantages.

Advantages of Glyphosate: 
  • Non-selective, meaning it will kill all plants that it comes into contact with.
  • Can be used on a variety of weeds, it's effective against almost all plant life.
  • Less expensive than triclopyr - sometimes upto 10x less expensive per litre!
  • Breaks down quickly in the environment so you can safely replant in the same area.
Disadvantages of Glyphosate: 
  • Can leach into water, causing contamination (it's toxic to aquatic invertebrates).
  • Cannot be used in lawns as it will kill your grass very effectively.
  • Drift can happen causing damage to neighbouring plants if care is not taken.
Advantages of Triclopyr: 
  • Selective, meaning it will only kill certain plant species lessening accidental drift.
  • Better for killing weeds in a lawn as it won't kill most types of grass.
  • Once applied there is very little chance that it will drift into water or neighbouring plants.
Disadvantages of Triclopyr: 
  • More expensive than glyphosate (sometimes upto 10x more expensive per litre!)
  • Can be toxic to beneficial insects (see below for studies on bees etc)
  • Can be more difficult to use than glyphosate & may be restricted to professionals.

Can you mix Roundup (Glyphosate) and Triclopyr?

In theory the mixture of Triclopyr and Glyphosate seems like a match made in heaven. Both target a wide spectrum of weeds and together they target almost every kind of unwanted vegetation, if the mixture didn't kill it, it would almost certainly harm the weeds.

But the big question is: Can you mix RoundUp with Triclopyr?

Yes! You can safely mix these two strong weed killers without ill effects. This is especially useful if clearing a large area with a mixture of broadleaf and woody vegetation.

Neither of these two herbicides have long lasting effects in the soil therefore you can safely use them together and replant in the same area after all the weeds are gone.

What is another name for Triclopyr?

Triclopyr is the active ingredient in SBK Brushwood Killer as it is commonly known in the UK.

Typically it is used to kill tough weeds like Brambles, Ivy, Thistles & Dock. There is no other known names for Triclopyr but it is the active ingredient in many types of weed killer.

Is Triclopyr absorbed by roots?

Yes, triclopyr is absorbed by the roots of plants. In addition, it can be absorbed through the leaves and stems of plants. The absorption of triclopyr by plants occurs when the chemical is applied to the foliage and soil.

Once absorbed, it is then transported throughout the plant, including its roots. This allows the chemical to be effective in controlling or killing weeds, brush, and other unwanted vegetation.

One of the reasons Triclopyr is often used against deep rooted perennials such as Brambles, Thistles and Docks is that it is effective even when you cut them back whereas other weed killers such as Glyphosate must be applied to the foilage & not the soil.

Is Triclopyr safe around trees?

Yes, triclopyr is generally safe to use around trees when applied according to the manufacturer’s instructions. Triclopyr is often used to kill Ivy on trees, great care should be taken when doing so as Triclopyr may penetrate the outer bark and harm or even kill mature trees.

When killing Ivy on trees you should clip the Ivy at the base of the tree and paint the Triclopyr on neat at onto the stems, this will prevent any contamination.

How to kill saplings with Triclopyr

Triclopyr is often used to kill unwanted saplings in verges or around homes. Unlike mature trees, Triclopyr is much more easily absorbed and transported around young saplings.

  • Wear protective clothing / gloves before applying the weed killer.
  • Dilute according to the manufacturers instructions.
  • Spray or paint the Triclopyr all over the sapling.
  • Ensure the whole sapling is covered in the solution.
  • Wait 4-6 weeks then re-apply if needed.

What are the risks of Triclopyr?

Triclopyr is generally considered safe to use but as with all Herbicides there are risks:

  • Can cause eye corrosion: When applying care should be taken not to get the solution into your eyes, wear safety goggles before & whilst applying.
  • Can cause skin irritation: Cover all exposed skin whilst applying the product.
  • High oral doses over long periods result in limited and reversible kidney and liver effects.

Whilst all herbicide use carries risk, Triclopyr is believed to be a low risk (non carcinogenic to humans) weed killer when used according to the manufacturers instructions.


Is Triclopyr bad for dogs & pets?

It can be toxic to mammals, aquatic life and can be hazardous to pets and other animals if ingested. According to the Environmental Protection Agency, Triclopyr is moderately toxic to dogs and cats, with an oral LD50 (the amount of a substance needed to kill 50 percent of a test population) of 874 mg/kg in rats.

Exposure to triclopyr can cause vomiting, diarrhoea, inappetence, depression, weakness and anorexia in dogs. If your dog has been exposed to triclopyr and exhibiting any of these symptoms, it is important to take them to a veterinarian as soon as possible.

Treatment may include decontamination, such as inducing vomiting, gastric lavage or activated charcoal to absorb any remaining chemical in the gastrointestinal tract.

The vet may also administer intravenous fluids and medications to prevent or treat seizures, which can be a complication of triclopyr poisoning. The veterinarian may also monitor the dogs electrolyte levels, as triclopyr can cause electrolyte imbalances.

Please always read the label of your Triclopyr weed killer to ensure safe use around pets & dogs.

Is Triclopyr harmful to bees?

Bees are a hot topic when it comes to herbicide use.

Some weed killers have been blamed for decimating the worlds bee populations but in the case of Triclopyr, it has been deemed "relatively non toxic" to bees. However weeds and unwanted foliage provide a vital nutrient source for bees around the year, please consider the bees.

How long does it take for Triclopyr to work?

Triclopyr isn't the fastest weed killer but it does get to work quickly. Once applied you should start to notice some affects after 7 days but it may take 2-4 weeks for it to kill your weeds.

It should be noted that your weeds may appear to grow more quickly after applying Triclopyr, this is normal, it causes unstable growth before the ultimate death of the weeds.

How long does Triclopyr need before rain?

Triclopyr is typically diluted in water then applied to the unwanted vegetation. If it rains the solution is further diluted making it much less effective.

Most Triclopyr herbicides are rainfast within 6-8 hours and best applied between May - October.

You should never apply herbicides in rainy, windy or freezing conditions.

Does Triclopyr work in winter?

No, please do not apply Triclopyr in the winter months. There has been several studies with treatment of Brambles and other woody plant species during the winter.

The Triclopyr had some affect at reducing the Bramble cover but was much less effective against everything else (90% less effective) - Triclopyr is best applied when your weeds are actively growing: typically between May & October.

What is the best way to apply Triclopyr?

All weed killers are best applied through a sprayer (knapsack, pressure or trigger) with a fine mist. This is the most efficient, accurate & safe way to apply herbicides. It is best to apply on a day with minimal wind to prevent accidental drift.

You can also paint Triclopyr directly onto the weeds, this is especially useful when killing Ivy on trees or Brambles that have grown over plants you'd like to keep.

DO NOT use a watering can to apply Triclopyr (or any other weed killer!) not only is it inefficient, you are literally pouring money away and may damage the environment.

Does Triclopyr harm grass?

Typically Triclopyr based weed killers are used to kill brush and tough weeds in and around grass, it is not usually used as a lawn weed killer but it can be as it also controls broad leaf weeds.

One of the main advantages Triclopyr has over Glyphosate is that when used normally it won't kill grass, when dealing with tough to kill weeds such as unwanted saplings, Ivy & Brambles near grass it is advisable to use Triclopyr or at least try it before resorting to Glyphosate.

When using triclopyr, it is important to avoid using it at high levels as this can cause damage to grass. If a higher concentration of triclopyr is being used, it is essential to apply it carefully and only target the weeds, avoiding contact with grass. 

Additionally, it is important to water your grass after applying triclopyr to reduce the risk of the grass becoming damaged. This is especially important if a high concentration has been used. 

It is also important to follow the manufacturer’s instructions when using triclopyr to ensure you are using it correctly, as this will help to ensure the grass is not damaged by the product.

When should I apply Triclopyr to my lawn?

Firstly, I must stress there are much better lawn weed killers than Triclopyr such as 2,4-D - Triclopyr does control certain broadleaf weeds but there are many types of weed it won't kill.

If using Triclopyr in and around your lawn it is best applied when your weeds are actively growing (May to October), apply on a day with no chance or rain, little wind and do not apply in the winter, Triclopyr doesn't work very well in winter.

Triclopyr works well against Nettles, Docks & Thistles growing in lawns or against Ivy / Brambles growing / overcrowding your lawn.

How do I apply Triclopyr to my lawn?

Always read the label and dilute Triclopyr according to the manufacturer, this will prevent you accidentally harming your grass, Triclopyr used in high doses can harm grass.

If your using Triclopyr to kill tough weeds in your lawn it is best applied through a sprayer (knapsack, pressure or trigger). Brambles and Ivy may need more accurate treatment as the doses required may be higher - you can paint the Triclopyr directly onto the leaves and stems.

How often can I apply Triclopyr to my lawn?

You killed the Docks, Thistles & Nettles in your lawn but missed a couple of spots or they didn't completely die, now your wondering how long do you have to wait before re-applying Triclopyr?

It is always important to read the manufacturers guidelines but typically you should wait 4-6 weeks before re-applying Triclopyr based weed killers this will help prevent damaging your grass.

What weeds does Triclopyr target?

Triclopyr targets a wide range of weeds but is mainly used to kill brush / woody / viney weeds. It is effective against most broadleaf weeds but is mainly used to control:

  • Poison Ivy: An invasive, toxic plant with three shiny, pointed leaves and a red stem. It is found in wooded areas in North America, Europe, and East Asia.
  • Poison Oak: A plant with three lobed leaves and yellow-green berries, found in North America. It is a member of the sumac family and is known for its irritating, itchy rash when touched.
  • Nettles: A tall, herbaceous plant with small green leaves and tiny, stinging hairs. It is found in Europe, North America, and parts of Asia.
  • Docks: A perennial weed with long, pointed leaves and yellow flowers. It is found in Europe, North America, and parts of Asia.
  • Brambles: A thorny, woody shrub with small, white or pink flowers. It is found in Europe and North America.
  • Wild Violet: A low-growing plant with purple, heart-shaped leaves and small, fragrant flowers. It is found in Europe and North America.
  • Wild Carrot: An invasive, biennial weed with white flowers and a taproot. It is found in Europe and North America.
  • Kikuyu Grass: A fast-growing, invasive grass with long, thin blades. It is found in Africa, Australia, and New Zealand.
  • Plantain: A weed with broad, oval leaves and small, greenish-white flowers. It is found in Europe, North America, and parts of Asia.
  • Ground Ivy: A low-growing weed with round, scalloped leaves and small, blue-purple flowers. It is found in Europe and North America.
  • Dandelion: A perennial weed with bright yellow flowers and deeply lobed leaves. It is found in Europe, North America, and parts of Asia.
  • Clover: A low-growing weed with three-lobed leaves and small, white or pink flowers. It is found in Europe, North America, and parts of Asia.
  • Bull Thistle: A tall, spiny weed with purple-pink flowers. It is found in Europe, North America, and parts of Asia.
  • Black Medic: A low-growing weed with yellow flowers and clover-like leaves. It is found in Europe, North America, and parts of Asia.
  • Ragweed: An invasive, annual weed with small, yellow-green flowers. It is found in North America and parts of Europe.

Triclopyr does target many other weeds - the above is what it is most commonly used to target.

Is Triclopyr restricted use?

Here in the UK home owners may use SBK Brushwood killer which comes in concentrated or ready to use form, the active ingredient is Triclopyr - it's use is not restricted.

Higher concentrated or more pure forms of Triclopyr may be restricted for professional use only.

How long does Triclopyr stay in the soil?

The half life of Triclopyr in soil is 30-90 days with the average being 45 days. This depends entirely on how much and how high of a dose you used. Triclopyr will persists on the longer range of that estimate in cold or dry conditions.

Unlike Glyphosate, Triclopyr doesn't bind tightly to soil and is highly mobile and can be absorbed into the roots then translocated throughout the whole plant.


Closing thoughts

In the UK most homeowners will be exposed to Triclopyr by the brand name SBK Brushwood Killer which is the most popular Triclopyr based weed killer in the UK.

It's use recently has sky rocketed as people look to avoid Glyphosate based weed killers however Triclopyr is much less effective against certain weeds when compared with Glyphosate.

Triclopyr is best used when you have woody / viney or tough weeds growing in and around lawns. Many turn to Triclopyr to kill Nettles, Thistles & Docks growing in lawns as it won't kill your grass and is highly effective against these types of weed.


We get a lot of questions about SBK brushwood killer (active ingredient : Triclopyr), we've answered some of the most popular ones below & if you have any others please comment below and someone will be happy to help you.

Is SBK Brushwood Killer safe?

Yes, it is generally considered safe for home use. It is practically non toxic to humans, animals, birds and fish. You should always follow the manufacturers guidelines when using any kind of herbicide.

Is SBK a glyphosate?

No, SBK Brushwood Killer doesn't contain Glyphosate.

How does SBK Brushwood Killer Work?

SBK is absorbed through the leafs, stems and roots of the weeds and translocated throughout the whole plant. When applying you may notice your weeds start to grow larger - at least initially.

This uncontrolled growth inevitably leads to their death.

How quickly does Brush Killer work?

It's not the fastest weed killer. You should start to see results within 7-10 days and your weeds should die within 2-4 weeks.

Does rain affect Brush Killer?

Yes. Please apply SBK brush killer on a day with no forecast for rain. As it is diluted in water, rain will dilute it further making it much less effective.

What is the active ingredient in SBK Brushwood Killer?

Triclopyr! SBK is used to kill tough weeds like Brambles, Ivy, Nettles, Thistles, Docks & many more kinds of hard to kill weeds.

About the author 


Hey there, I am founder and editor in chief here at Good Grow. I guess I've always known I was going to be a gardener. I'm on a mission to share my UK based weed control & lawn care tips with you all. If you have any queries please post in the comments below.

  • Hello. A great read, and has been very informative, thank you. What is the concentration of triclophyr in SBK?
    Very many thanks.

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