Strongest weed killer UK: the legal ceiling on what you can buy

There is no such thing as an industrial weed killer in UK law. Every product is either amateur-approved or professional-only, and that line is about training, not strength. The strongest glyphosate liquid you can legally buy is 360 g/L, which is the identical concentration to the standard professional amenity product. Here is how high the ladder actually goes, what a certificate does and does not buy you, and why the tank barely gets stronger as you climb.

By The Weed GuyLast updated 2 September 2026

The short version

The strongest weedkiller a member of the public can legally buy in Great Britain is a 360 g/L glyphosate concentrate, sold in garden centres with no licence and no paperwork. Roundup ProActive, the professional amenity product councils and contractors use, is also 360 g/L. The professional ceiling is 550 g/L, so the gap is roughly one and a half times, not the fifty times you keep reading. What the professional tier really costs you is a certificate you must hold to spray it at all, even on your own drive.

How strong it actually gets, tier by tier

Every figure below comes off the HSE pesticide registers rather than a retail listing, because a listing will tell you a product is super strength and never tell you the number. The last column is the one people never think to ask about, and it is the one that decides what you are allowed to do.

Tier	Glyphosate in the bottle	What that becomes in the tank	Who may legally use it
Ready-to-use trigger bottle	7.2 g/L (Roundup Fast Action), 8.39 g/L (Resolva 24H)	Already mixed. What is in the bottle is what hits the weed.	Anyone. No certificate, no paperwork.
Mid-strength amateur concentrate	90 g/L (Doff Advanced Concentrated, MAPP 18107)	Whatever the pack rate works out at. Read the bottle in your hand.	Anyone.
Amateur concentrate, the liquid ceiling	360 g/L (Gallup Home and Garden MAPP 17672, Roundup Ultra MAPP 18850)	Roundup Ultra puts brambles at 10 ml per litre of water, which is about 3.6 g/L in the tank.	Anyone. This is the strongest glyphosate liquid on open sale in Great Britain.
Amateur granule	680 g/kg (Total Ground Clear, MAPP 20114)	Per the pack rate. A solid, so it is not directly comparable to a g/L figure.	Anyone. Stronger in the pack than any professional liquid.
Professional amenity, standard	360 g/L (Roundup ProActive MAPP 17380, Rosate 360 TF MAPP 17682)	Commonly quoted around 20 to 25 ml per litre, so roughly 7 to 9 g/L. Check your own pack.	Specified certificate holder only, or someone in training under their direct personal supervision.
Professional amenity, high load	490 g/L (Gallup Hi-Aktiv Amenity, MAPP 17681)	12 ml per litre for general use, which is 5.88 g/L in the tank. 18 ml/L against perennial broad-leaved weeds, 8.82 g/L.	Specified certificate holder only.
Professional, the Great Britain ceiling	550 g/L (Pitch, MAPP 15485, Nufarm)	I could not verify its label rate, so I am not quoting one.	Specified certificate holder only.

Read the third column against the first and the whole premise of the question falls apart. The bottle gets nearly eight times stronger as you climb. The tank barely moves.

There is no such thing as industrial weed killer

About three and a half thousand people a month search for industrial weed killer in this country. It is not a product category. It is not a strength grade. It has no standing in the regulations at all.

Great Britain sorts every plant protection product into exactly two classes: amateur, meaning approved for use in a home garden by someone with no training, and professional, meaning approved only for people who hold the relevant certificate. The HSE register carries one field for this with those two values in it. There is no third box for industrial, commercial, contractor or trade.

The word does appear once in the regulations, and it is worth knowing where, because it is the source of the confusion. The Plant Protection Products (Sustainable Use) Regulations define an "industrial herbicide" when they set out which products count as agricultural for the purposes of who needs a certificate to sell them. That is a rule about shopkeepers, not about strength. Nothing turns on it for you.

So when a marketplace listing says industrial strength, extra strong, or professional grade, you have learned nothing. The only question that carries any weight is whether the product is amateur-approved, and you can settle that yourself in about a minute on HSE's garden database. If it is not on there, it is not something an untrained member of the public may lawfully use, whatever the seller has chosen to call it.

The amateur line is a training line, not a strength line

Here is the part nobody writes down.

Gallup Home and Garden is on the HSE amateur register under MAPP 17672 at 360 grams of glyphosate per litre. Roundup Ultra, MAPP 18850, is also amateur and also 360 g/L. Both are on open sale. Neither asks you a single question at the till.

Roundup ProActive, the amenity product that gets sprayed on pavements and kerbs by people in high-vis, is MAPP 17380 at 360 g/L. Rosate 360 TF, another trade standard, is MAPP 17682 at 360 g/L. The same number, on both sides of a line everybody assumes is a wall.

Go looking for the amateur ceiling properly and it holds up. Read every glyphosate concentration on the amateur register and you get 3.6, 7.2, 8.39, 72, 90, 120, 125, 144, 151.04, 151.4, 170 and 360 grams a litre. Nothing above 360 as a liquid. And the single strongest amateur glyphosate product in Great Britain is not a liquid at all: it is Total Ground Clear, MAPP 20114, a water-soluble granule at 680 grams per kilogram, which anyone can buy. That is a heavier loading than any professional liquid on the register.

The professional tier does go higher in the bottle. Pitch, MAPP 15485, is 550 g/L. Amega Duo and Clinic Hi Load are 540. The Gallup Hi-Aktiv products are 490 and Roundup ProVantage is 480. But that is roughly one and a half times the amateur ceiling, not an order of magnitude, and it is the top of the professional range against the top of the amateur one. What actually separates the two registers is who is allowed to pull the trigger.

The bottle is steep. The tank is nearly flat.

This is the arithmetic that turns the question inside out, and I have not found a single page doing it.

Concentrate strength is not the dose. It is the dose divided by however much water the label tells you to add, and the label rate goes down as the concentration goes up precisely so that the finished spray lands in the same place.

Work it through on the strongest glyphosate most operators ever touch. Gallup Hi-Aktiv Amenity is 490 g/L, and its own label gives 12 ml of product per litre of water for general use. Multiply it out: 490 times 0.012 is 5.88 grams of glyphosate per litre in the tank.

Now pick up a Roundup Fast Action trigger bottle in a supermarket. It is 7.2 g/L, ready mixed. Resolva 24H is 8.39 g/L. Both of them are stronger on the leaf than the 490 g/L professional concentrate mixed to its own general rate. The label does allow 18 ml per litre where perennial broad-leaved weeds are present, which gets you to 8.82 g/L, and that is the honest top end. It is still the same ballpark as a shop bottle.

The same thing happens one tier down. Roundup Ultra is a 360 g/L concentrate, and its own label rate for brambles is 10 ml per litre of water, which works out at about 3.6 g/L in the tank, half the strength of the ready-to-use bottle everyone says is too weak. I worked that one through in full on the bramble weedkiller resource, because it changes what you buy for a bramble entirely.

So what is a concentrate actually for? Cost and control. You are buying active ingredient instead of shipping water, and you are getting a tank you can calibrate across a whole drive rather than a trigger you squeeze until your hand aches. The arithmetic for scaling any label rate to a 5 or 15 litre tank is worked through on the glyphosate concentrate strengths and mixing rates resource, and that is the page to read before you mix anything. This one is about how high the ladder goes, not about the measuring jug.

The certificate: what it really requires, including on your own drive

The rule is one sentence long and it is unambiguous. The Plant Protection Products (Sustainable Use) Regulations 2012 say that no person shall use a plant protection product authorised for professional use unless they hold a specified certificate or work under supervision.

Three things follow from that, and most of what you will read online gets at least one of them wrong.

It applies to everyone, whatever your age. There was an exemption for anyone born on or before 31 December 1964 spraying on their own or their employer's land, and it is the origin of every out-of-date forum post on the subject. It was written with an expiry in it. It ended on 25 November 2015, and since 26 November 2015 everyone using a professional product has needed a certificate.
It applies on your own property. There is no private-garden carve-out, no unpaid-work carve-out and no it-is-my-driveway carve-out. Ownership was only ever relevant to that expired exemption. HSE's own guidance on using a professional product in a home or garden runs a short test, and one of the questions on it is whether the user holds a certificate where one is needed.
Supervision is narrower than it sounds. The regulations define working under supervision as being under the direct and personal supervision, and in the presence, of a certificate holder, where that supervision is being provided for the purposes of training. All three conditions have to hold. A qualified mate on the end of a phone is not supervision, and neither is a qualified mate stood next to you who is not actually training you.

The certificate itself is what used to be called a Certificate of Competence and is now a specified certificate. For a knapsack or hand-held sprayer it means the PA1 foundation unit plus PA6, awarded through one of the designated bodies such as City and Guilds or Lantra. It is a real course with a real assessment, not a form you fill in.

And the sting in the tail: HSE guidance states that the seller is not required to check that the buyer or intended user holds a certificate, only that they are recommended to remind them of the obligation. So an agricultural merchant will happily sell you a 5 litre drum of 490 g/L amenity glyphosate. The illegality attaches to putting it through a sprayer, not to owning it, which is exactly the wrong way round for anyone assuming that if they could buy it they must be allowed to use it.

Kills everything, or stops anything growing back? They are not the same purchase.

Two and a half thousand people a month search for the strongest weed killer that kills everything, and a good share of them actually want the second thing on this list rather than the first.

What you actually want	What to shop for	The catch
Kill everything growing here now	Non-selective and systemic. Glyphosate is the one, at whatever concentration you can lawfully get.	It kills the root, so it does not come back from the same plant. It does nothing at all about the next seed that lands.
Kill the weeds but leave the grass	Selective. Triclopyr for woody weeds, or the lawn actives such as MCPA, dicamba, fluroxypyr and clopyralid.	Selectivity is a hormone or enzyme difference between plant families, not a weaker dose. Nothing to do with strength.
Stop anything growing here for months	Residual, which is soil-acting. Amateur: diflufenican with glyphosate (Pathclear, MAPP 12599, 20 + 125 g/L).	This is the one where the professional tier genuinely pulls ahead. Pistol (MAPP 18854) is exactly double on both actives.
Burn the top off today and see it work	Contact. Pelargonic acid, acetic acid, the glyphosate-free bottles.	The fastest-looking option and the one that reaches nothing. The root is untouched, so it regrows.

Glyphosate leaves nothing behind in the ground. That is usually sold as a virtue, and it is one, but it also means it does precisely nothing about the seed that blows onto your drive next week. Someone who sprays in April, sees a clean drive in May and finds it green again in July has not been sold a weak product. They have been sold a non-residual one and expected residual behaviour from it.

Residual is the property they were after, and it is where the amateur and professional registers genuinely diverge rather than nearly touching. The amateur route is diflufenican paired with glyphosate, which is what Pathclear EasyMix is: MAPP 12599, 20 g/L diflufenican and 125 g/L glyphosate. The professional equivalent is Pistol, MAPP 18854, at 40 g/L diflufenican and 250 g/L glyphosate. Exactly double, on both actives, which is about as clean a comparison as this subject ever offers.

Pistol's approved label claims residual control for at least three months and up to four on hard surfaces. I am attributing that to Pistol deliberately, because I could not source an equivalent claim from a current amateur Pathclear label and I am not going to put a professional product's duration against an amateur one and hope. The label also warns that where diflufenican is applied in successive years its levels build up in the soil, and asks for at least six months before sowing or planting. A residual is a commitment to keeping ground bare, not a stronger version of a normal weedkiller. More on how these behave in a joint on whether path and drive weedkiller works on block paving.

The really strong stuff existed, and it was banned

If you are old enough to remember a weedkiller that kept a gravel drive completely bare for a season, and you are convinced everything on sale now is watered down: you are right, and it is worth saying so plainly instead of pretending the good old days are a myth.

Sodium chlorate is the one people mean. It went through a formal European refusal in November 2008, on the grounds of unacceptable exposure to operators and insufficient data on a metabolite leaching into groundwater. Authorisations were withdrawn by 10 May 2009 and the last lawful day to use up what was left in the shed was 10 May 2010. The older path and drive residuals had already gone: diuron was refused in 2007, with authorisations withdrawn by 13 December 2007, and simazine and atrazine were both refused on 10 March 2004.

So the honest version is that the ceiling genuinely came down, and it came down by regulation rather than by manufacturers quietly weakening anything. Chasing a stronger bottle to get that old performance back is chasing something that no longer exists at any price, on either register. What is left is glyphosate, which is better at killing the plant and worse at keeping the ground empty, plus a much shorter residual option. Adjusting your expectations is cheaper than adjusting your shopping.

So what should you actually buy?

If the job is a drive, a path or a patio and you want what is growing there dead down to the root, buy a 360 g/L amateur glyphosate concentrate and a sprayer, and mix it to the label rate on a dry morning. That is the top of what you can lawfully use, it is the same concentration as the professional standard, and no amount of further shopping will improve on it.

If you want the ground to stay bare afterwards, add a residual product to the plan rather than a stronger one, and read the label's area-of-use wording before it goes anywhere near soil you intend to plant in.

If what you are fighting is a specific tough perennial, the answer is a different active or a different delivery method rather than a bigger number. Which type suits which job is worked through separately on the best weed killer UK resource, and the underlying mechanism behind all of it is on what actually kills weeds for good.

And if it still looks alive a week later, that is almost never a strength problem. A systemic product takes two to four weeks and shows you very little in the first few days, which is covered in how long weed killer takes to work. Anything that browns off by teatime burned the leaf and left the root alone.

The strongest one you can legally buy

This is where the page lands. 360 g/L glyphosate is the ceiling on the amateur market, and the professional bottles above it are not stronger, only restricted.

What I’d use

Glyphosate concentrate, 360 g/L

Gallup Home & Garden Glyphosate Weedkiller (1 litre)

The one Gallup a homeowner can legally buy and use: a 1 litre glyphosate concentrate at 360 g/L, approved for home and garden use under MAPP 17672.

It is the same active, the same 360 g/L loading and the same isopropylamine salt as the professional Gallup XL, and its single label rate of 24 ml per litre of water is exactly the rate the professional labels reserve for perennial broad-leaved weeds. The difference between the two bottles is the authorisation printed on them, not the chemistry inside, and this is the side of that line you are allowed to stand on.

Active ingredient: Glyphosate, 360 g/L, as the isopropylamine salt
Formulation: Soluble concentrate you dilute yourself
Approval: MAPP 17672, labelled for use only as a home and garden weedkiller
Mixing rate: 24 ml per 1 litre of water, per the label
Coverage: 40 sq m per litre of made-up spray, so roughly 1,667 sq m per bottle
Rainfast: Rain within 6 hours may reduce effectiveness, per the label
Size: 1 litre of concentrate

Watch out for

No measuring cap in the bottle. Check a cup arrives, or the dose is guesswork.
One re-treatment a season, and it takes four weeks. Do not go again early.
Not for lawns. It is non-selective and takes the grass too.
Resellers dominate the listing, so check the label that arrives is Barclay.
"Super strength" is keyword stacking. It is 360 g/L, same as professional Gallup XL.

Check the price on Amazon

That’s an affiliate link: buy through it and I earn a small commission at no extra cost to you. It doesn’t change what I recommend or what I say is wrong with it. More on how that works in the affiliate disclosure.

No brand pays for a mention here, and nothing on this page is a paid-for opinion. The card above is an affiliate link, so I earn a commission if you buy through it, at no extra cost to you. It buys no product a kinder write-up, which is why the watch-outs sit on the same card as the reasons to buy.

About this resource

I'm The Weed Guy, one bloke who is qualified to spray professional weedkiller. Every concentration and MAPP number on this page was read off the HSE pesticide registers, which are public and which anyone can search: there is one register for amateur garden products and a separate one for professional products, and the split between them is the spine of this whole page. The legal wording comes from the Plant Protection Products (Sustainable Use) Regulations 2012 and HSE's own guidance on them, not from a forum.

Where I could not verify something it is not here, and where a figure belongs to one product I have said which. I have not quoted a label mixing rate for Pitch because I could not source one. I have not put a residual duration against the amateur Pathclear, because the three-to-four-month figure I could verify belongs to the professional Pistol label and it would be dishonest to lend it to a product at half the loading. I have not run any of these products against each other in a test and I am not going to pretend otherwise.

One date worth pinning: glyphosate's Great Britain approval currently runs to 15 December 2026 while HSE completes a renewal assessment. That is close enough that this page will need revisiting, so check the current position rather than taking any website's word for it, including mine.

The commercial position, plainly: nothing here is a paid-for opinion and no brand sponsors this site. Products are named on this page for one reason only, which is that their registered concentration or their legal status proves a point the marketing does not. Naming Pitch at 550 g/L is not a recommendation to go and get some, and I would rather write the page that way round than hand you a shopping list for a question whose real answer is about what you are allowed to use.

Common questions

What is the strongest weed killer you can buy in the UK?

For a liquid, 360 g/L glyphosate, and you can buy it in a garden centre without any paperwork at all. Gallup Home and Garden (MAPP 17672) and Roundup Ultra (MAPP 18850) both sit on the HSE amateur register at that concentration, and that is the top of the amateur liquid ladder. Nothing stronger exists as an amateur liquid: the full set of glyphosate strengths across the amateur range runs 3.6, 7.2, 8.39, 72, 90, 120, 125, 144, 151.04, 151.4, 170 and 360 g/L. There is one product above it, and it is a solid rather than a liquid: Total Ground Clear (MAPP 20114) is an amateur water-soluble granule at 680 g/kg.

Is there such a thing as industrial weed killer?

Not as a legal category, no. Great Britain classifies every plant protection product as either amateur or professional, and that is the whole list. The HSE register carries a single field with those two values and nothing else. "Industrial strength" on a marketplace listing is marketing language and tells you nothing about the product. The only place the word appears in the regulations is a clause defining an "industrial herbicide" for the purposes of who needs a certificate to SELL a product, which is a sale category rather than a strength grade. The question that actually matters is whether the product is amateur-approved, and you can check that yourself on the HSE garden database.

Is professional weed killer actually stronger than what a shop sells?

In the bottle, sometimes, and by less than you would think. The professional ceiling in Great Britain is Pitch at 550 g/L, with Amega Duo and Clinic Hi Load at 540 and the Gallup Hi-Aktiv products at 490. Against an amateur ceiling of 360 g/L that is about a 1.5 times gap, not the fifty-fold gap the internet keeps repeating. And Roundup ProActive, the best known professional amenity product of the lot, is 360 g/L, which is exactly the same as the Roundup Ultra sold to homeowners. The professional tier buys pack size, label-approved use areas and formulation, not a different chemical.

Do I need a licence to spray professional weedkiller on my own driveway?

Yes, and this is the trap. The Plant Protection Products (Sustainable Use) Regulations 2012 say plainly that no person shall use a product authorised for professional use unless they hold a specified certificate or are working under supervision. There is no exemption for your own land, your own garden or unpaid work. The certificate is what used to be called a Certificate of Competence, and for a knapsack or hand-held sprayer it means the PA1 foundation unit plus PA6, awarded through bodies such as City and Guilds or Lantra. Amateur products carry no such requirement, which is the entire point of the amateur category.

I thought the certificate rule only applied if you were born after 1964?

That has not been true since 2015, and it is the single most repeated piece of out-of-date advice on this subject. The birth date worked the other way round: anyone born on or before 31 December 1964 who sprayed professional products on their own or their employer's land was exempt, under what everyone called grandfather rights. That exemption was written with an end date in it and it stopped on 25 November 2015. From 26 November 2015 everyone using a professional product has had to hold a specified certificate, whatever their age.

If I need a certificate, how am I able to buy it?

Because the duty sits on the person spraying, not the person selling. HSE guidance is explicit that the distributor or seller is not required to check that the purchaser or intended user holds a certificate, and only recommends they remind customers of the obligation. So a trade counter or an online agricultural supplier will sell you a 5 litre drum of amenity glyphosate without asking a single question, and you will have bought something you are not lawfully allowed to put through a sprayer. Easy purchase is not permission.

What is the strongest weed killer that kills everything?

Any non-selective systemic weedkiller kills everything green it lands on, and glyphosate is the one that does it while also reaching the root. But "kills everything" and "stops anything growing back" are two different properties and people buy the wrong one constantly. Glyphosate deals with the plants that are there today and leaves nothing in the ground, so the next seed that blows onto your drive germinates perfectly happily. If you want bare ground to stay bare you need a residual product, which is a different chemistry doing a different job.

What is the strongest weed killer that stops weeds coming back?

Residual is the word to shop for. On the amateur side that means the diflufenican and glyphosate combinations, such as Pathclear EasyMix (MAPP 12599) at 20 g/L diflufenican with 125 g/L glyphosate, or Rigour (MAPP 18356) which pairs 120 g/L glyphosate with 2.22 g/L sulfosulfuron. This is the one area where the professional tier is genuinely and measurably ahead rather than marginally: the professional product Pistol (MAPP 18854) is exactly double the amateur Pathclear on both actives, 40 g/L diflufenican and 250 g/L glyphosate. Pistol's own approved label claims residual control for at least three months and up to four on hard surfaces.

Why does one bottle say 360 g/L and another say 441 g/L?

Because they are usually the same bottle described two ways, and it catches people out constantly. Roundup Ultra's label reads "360 g/l (28.47 %w/w) glyphosate acid (present as 441 g/l (34.86 %w/w) potassium salt of glyphosate)". The 360 is the glyphosate acid equivalent, which is the figure that matters and the one everyone compares on. The 441 is the weight of the salt the acid is formulated as, which is inevitably higher because you are weighing the acid plus whatever it is bonded to. A product quoted at 441 is not stronger than one quoted at 360. Compare acid equivalent against acid equivalent or you are comparing nothing.

What happened to the weedkiller that kept the ground bare for a year?

It was banned, and there are dates on it. Sodium chlorate is the one most people are remembering, and it went through a formal European refusal in November 2008 on the grounds of unacceptable operator exposure and missing data on a metabolite leaching into groundwater. Authorisations were withdrawn by 10 May 2009 and the last lawful day to use up existing stock was 10 May 2010. The older path and drive residuals went the same way earlier: diuron was refused in 2007, and simazine and atrazine both in March 2004. So the honest answer to "nothing works as well as it used to" is that you are right, and it is a regulatory change rather than the manufacturers weakening anything.

Is there anything stronger than glyphosate for a driveway?

Not in the sense of a harder-hitting knockdown, no. Glyphosate is still the non-selective workhorse and there is no amateur product that outperforms it on killing what is growing. Glufosinate, which people sometimes ask about, is not an approved active substance in Great Britain and no glufosinate product is authorised here. What the professional market does have that the amateur market does not is longer residual chemistry, actives such as flazasulfuron, iodosulfuron and higher-loaded diflufenican, all professional-use only. So the honest framing is duration and concentration rather than raw potency.

Can I just mix it stronger than the label says?

No, and it is a worse idea than it sounds. The rate printed on the label is part of the product's conditions of authorisation rather than a suggestion, so going above it is using the product outside its approval. It also tends not to work: past a point, more glyphosate in the tank damages the leaf fast enough to interfere with the plant carrying it down to the root, which is the entire mechanism you are paying for. The lever that actually changes the outcome is where you put it, not how much you cram into the water.

Is glyphosate still legal in the UK?

Yes, as at August 2026. HSE extended its Great Britain approval to 15 December 2026 while a renewal assessment runs, and the GB Approvals Register as updated in August 2026 records no extension beyond that date. Renewal, if granted, could run for up to fifteen years; a refusal would mean products containing it were phased out. Northern Ireland is on a different footing, because EU plant protection rules continue to apply there under the Windsor Framework and the EU has already renewed glyphosate. It is a live date rather than a settled one, so it is worth checking the current position rather than trusting any page including this one.