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This article was last updated on September 8th, 2021 at 6:18 am

If you’re an avid gardener tackling weeds for the umpteenth time you’ll know the best weed killer for UK use will vary significantly. If you’re a beginner you can easily trip over and make huge mistakes that’ll lead to bazooka everything rather than just the weeds.

What are weed killers?

Weed killers are products that are used by gardeners and farmers to get rid of, and control the growth and spread of, unwanted plants, better known as weeds.

The list of plants that qualify for this ‘weed’ moniker is actually quite long, with everything from dandelions to lichens, and a whole lot in between, featuring on it. Weeds can pop up on your lawn, in your flower beds and borders, along your garden path, and even on your patio and decking, so it’s no surprise that there are so many different weed killer products to choose from.

Most of these products, however, are based on the same chemical called glyphosate as it is incredibly effective at killing pretty much all kinds of weeds, and doing so quite efficiently. The downside to glyphosate is that it is a little ‘too effective’ and will also kill any other plant life that it comes into contact with, as well as being able to cause humans physical harm if not used carefully.

In recent years, there have been more and more weed killers that are advertised as organic, or pet safe, being brought onto the market. At first glance you might think that these two labels mean the same thing, but they don’t.

Some ‘pet safe’ products still contain harmful chemicals, but are designed to dissipate quickly and so the area becomes safer for pets to enter after a certain length of time. Organic weed killers are usually based on acetic acid (basically vinegar) or something similar, and so are the safest to use, for yourself, family, pets, and your garden, but they are not usually as effective as glyphosate-based products.

There are also products out there called weed and feed, and these are usually good for lawns as they are a mix of chemicals that can kill weeds but also fertilise your lawn, giving you the best of both worlds. The effectiveness of these kinds of products does vary quite a lot from brand to brand, so watch what you spend your money on.

Possible problems with weed killers

As weed killers are essentially poisons, not to mention toxic is most cases too, there is a lot that can go wrong when using them. This is why you should always follow the instructions on the products packaging, and also wear protective clothing like gloves, a mask, and even eye protection.

You need to be very careful where you spray the majority of weed killer products, as it only takes a little, accidental, splash in the wrong place and you prize flowers and vegetables can easily become collateral damage.

Even your lawn can be irreversibly damaged by using the wrong kind of weed killer on it, so it’s important to do your homework before buying and applying any product. There are weed killers that are designed to be used on lawns, just as there are ones designed for patios, paths, and other areas and surfaces, so be sure to buy the right one for your needs.

If you have young children and pets that like to play in the garden, you need to get a weed killer that will dissipate quickly and become harmless, and you need to follow the manufacturer’s instructions on how long to wait accurately too. If not, it could lead to poor old Fido, or even your kids, coming to harm from leftover residue.

If you’ve read customer reviews of weed killers, you’ve probably seen that there is often mixed feedback from customers. Sometimes, these differing results are caused by people applying the weed killer in different conditions. For example, if you spray some weed killer but then there is rain later that day, or even a day later, you will probably find that the product is less effective than when applied during better conditions.

Example of using weed killers

As I just mentioned above, the conditions under which you apply a weed killer can affect its performance considerably. I was told this when I first started out gardening and so, when it came to my first time using the stuff, I waited until there was little chance of rain, and gave those weeds a good spraying.

After a few days I didn’t see much change in the state of the weeds, but the old guy who’d advised me about the weed killer and weather conditions also told me that patience is often key too, so I waited. However, after a week nothing much had happened so I went back to the place where I bought the weed killer and told them I thought there was a problem with it.

The person working there was actually very knowledgeable, and he smiled when I told him this before asking me if I’d watered the weeds a little before spraying. Of course, I told him that I hadn’t as I wanted the things dead, not growing and thriving!

He then explained that we had recently just had a particularly dry spell for the last few weeks, and that the weeds would be reacting to drought and this can make them less likely to absorb the weed killer. Therefore, giving them a light watering for a day or two before applying the weed killer should help.

I went home and followed his advice, and wouldn’t you know it, this time it worked wonders. So, if ever you’re having problems getting a product to work as expected, keep my little story in mind. You don’t want to apply weed killer in wet conditions as it will be washed away and run off, but you also don’t want to spray in drought conditions without watering the weeds a little first.

The ideal conditions are after a shower, but when you know that it will be dry for a couple of days after that. At this time, the weeds are receptive, and it also gives the weed killer time to be absorbed and do its job effectively.

If you want a weed killer for the lawn, it will be nothing like a weed killer with a ‘one purpose fits all’ product with super strength designed to eradicate weeds in your driveway or block paving for as long as possible. So we will take a good look at the best options available for each different application and below the review of each product you can find a useful buyers guide which will help you ensure you have the right weed killer.

Comparison table: What is the best weed killer in the UK: block paving and driveways? [Summer 2021 Review]

ProductWhat We ThinkPrice

Gallup home & garden glyphosate weedkiller, 2L

Gallup Home & Garden Glyphosate Weedkiller 2L + Free GardenersDream Cup & Gloves

  • FOR HOME USE - Can be used in your garden without the need of a spraying certificate...
  • STRONG WEEDKILLER - Effectively controls annual and deep-rooted perennial weeds
  • COMPATIBLE WITH PERSONAL SPRAYERS
  • USE RESPONSIBLY - Do not spray in rainy or windy conditions

Doff Glyphosate weed killer concentrate, multi-colour, 1 litre

  • Leaves no harmful residue
  • Treats up 416 sqm
  • Kills weeds and roots

Weedol ultra tough weed killer liquid concentrate

  • Ideal for ground clearance on untidy overgrown areas
  • Unique dual action fomulation
  • No measuring or mess
  • Kills brambles, nettles, thisles
  • Children and pets need not be excluded from treated areas (once dry)...

Scotts Miracle-Gro Roundup fast action weedkiller pump 'N go ready to use spray, 5 L

  • Fast action ready to use weed killer that kills the weeds and roots with visible results in 1-2 days...
  • Kills most garden weeds with a single application; up to 10 minutes of continuous spray when using 5 L...
  • Children and pets need not be excluded from treated areas (once dry)...
  • The Pump N Go pressure sprayer is easily refillable
  • Degraded in the soil by micro organisms

Gallup weedkiller is the strongest weed killer available domestically in my experience, that is after using all of the weed killers over the years in this review. It is super handy to have a commercial strength weed killer available for domestic use. It’s pretty simple to use too. Just add 30ml to a litre of water and fill a garden sprayer. If you don’t have one yet following that link will really help. Assuming you have a nice sprayer with an extension and variable mist, it’s then really easy to use so I would definitely go with the Spear and Jackson pump action sprayer. It can be applied without a spraying certificate and is exactly the same strength as professional weed killers (360g/l of Glyphosate). That pretty much sums the product up really. It’s really strong and it works great but there is a little more to discuss…

It’s actually so strong, it has no problem dealing with the nastiest problems like Japanese Knotweed and Ivy. If you have this type of issue then I would recommend using this product ahead of all others. If you have a large patch to clear then in about two weeks this will show tremendous signs of killing off most annual and perennials. Here’s a look at a ten day treatment that you can expect from someone who used this product.

This was kindly provided by Dave Andrews to amazon.com

So as you can see, despite being half the price of the brand names, it’s easily as effective and in my opinion, probably more so. This will eventually end up double the price with a fancy brand attached. Fortunately for now though, we can grab a bargain. When I am looking for the strongest weed killer domestically, I go straight to this product.

In terms of application, a pressurised sprayer will make life a doddle. Remember, this is extremely strong stuff so wear a mask and avoid windy conditions. Also, it goes without saying that you want to apply this when no rain is around. If it does rain shortly after application then you’ll need to pick another day that’s dry to re-apply, so don’t waste your time or the product itself. Plan well and aim for a nice sunny day.

Once it contacts soil, it is neutralised. That said, seeing as you will need a few weeks for the weeds to die off, there’s no rush to plant again. I would personally leave a couple of weeks minimum after application to begin planting to be on the safe side. As a patio or block paving de-weeder, many having claimed it works wonders, some have claimed it leaves a stain that then needs to be cleaned itself. I think this is a common problem with all weed killers on porous brick. My personal experience was the block paving came up just fine after I used a pressure washer. I don’t have anything overly powerful, just the WORX cordless pressure washer. Definitely blast your patio clean before you use a patio sealer or you’ll trap in any stains…

The same rules apply to this weed killer as all others in the review. Once the area is completely dry it’ll be OK for children and pets. This is the manufacturers guidelines and it’s reasonably inline with all other major brands with the active ingredient Glyphosate. I would take no chances though, I would wear a mask and goggles then pick a warm day with no wind at all to apply. This will give the best and safest results.

Pros

  • Super strong weed killer
  • Probably the strongest weed killer domestically
  • Super well priced
  • Works like all Glyphosate based weed killers
  • Treats hardy vines like Japanese Knotweed and Ivy
  • Suitable for more patio, block paving, and driveways

Cons

  • So popular it’s often out of stock!

2. Scotts Miracle-Gro Roundup fast action weedkiller pump 'N go ready to use spray, 5 L

As of writing in May 2020, the Roundup fast action weedkiller is easily one of the most powerful all purpose weed killers on the market. Quite frankly, Roundup would not have been my first choice to review. That would have been the Gallup offering but it’s out of stock at the moment. I’ve still included it in the review because once available again, it would be the go to for super strong strength. So the next best readily available is the Roundup offering.

There’s a few obvious reasons why I like Roundup. The package is ultra handy. Having its own spray applicator is a big win. If you’re doing this for the first time then you won’t have a pump pressure spray gun. A decent one that you trust to hold weed killer would set you back £25 alone. So buying this setup is ideal. Plus there’s nothing stopping you re-using this sprayer once empty with refills.

Fast acting is no gimmick. When it comes to results this really works. Like with almost all top weed killers it relies on Glyphosate which works to attack weeds both above and underground. Amazingly, their 48 hour claim is legitimate. You will start to see the weed literally wilt within a day or two depending on how hardy. It’s a little misleading though in the sense that the weed itself lives on for up to a month. And from my personal experience using this product myself, hardy deep rooted perennials take longer to show signs of giving up. Eventually they’ll die at the roots but this was the largest cause for negative feedback I have found with my customers to date too.

Obviously when a product claims to be fast acting within 48 hours you naturally assume finished, so can be a little disappointing. Never fear, it’ll work alright! From my experience, it works really well on both annual and perennial weeds. It’s particularly effective against your normal problems like stinging nettles, dandelions, and even hardier thistle. With the deep rooted weeds you’ll find they take longer to die off, don’t lose faith. Glyphosate is an incredibly powerful chemical and does it’s job well.

You’ll get about 150m2 of coverage, probably less if it hardy weeds as opposed to quick growing annuals. In any case one or two bottles will do most gardeners.

They claim it becomes inactive on contact with soil and dissolved by soil microorganisms. While I have no reason to doubt this, I would not replant vegetables in a hurry. While the WHO said ‘it’s probably carcinogenic to humans’, Euro scientists more recently found otherwise; that it is not a carcinogenic to us. How I read that is err on the side of caution. I would personally give it a couple of weeks and not the 7 days as Roundup stipulates. It’s nothing personal either, I just prefer safe over sorry and given gardening is about planning and the long haul, it shouldn’t make any difference to using this product if timed right!

One other useful point of reference is the spray nozzle. It works far better as a spot weed sprayer so to speak, rather than a fine mist sprayer to kill large patches. This is quite useful when aiming at weeds in block paving or areas on driveways.

Lastly before we look at pros and cons, the manufacturer suggests once this is dry, your pets and children will be ok. Please really ensure you allow ample drying time. A real handy tip here is to pick a time after a few days of dry weather and then ideally no breeze but we will go into this further in the weed killer user guide.

Pros

  • Cost effective with its own spray nozzle.
  • Child and pet safe
  • Great all round use
  • Well priced
  • One bottle lasts a mid size garden a summer normally
  • Breaks down in soil in 7 days

Cons

  • Occasional reports of weeds not dying (normally time issue)
  • Nozzle could adjust a little better
  • In my opinion, not quite as miraculous as the sales pitch makes me feel, but still a super product.

Here’s another great weed killer. This time it’s an offering from Weedol. I am going to go right off the bat and say this is an incredible product. You can use this weed killer to kill Brambles, Ivy, and other woody shrubs. But, don’t expect it overnight. This is a product for someone with time on their hands. The manufacturer suggests 28 days for weeds to die. I will happily tell you it’s taken longer myself when using this product. I still really like it, don’t get me wrong but be aware you need to be patient.

Almost all of my customers that have complained about this product have done so within a couple of weeks of purchase. You really need to give it a chance and watch the magic. The best bit for me is when the plant begins to die, it’ll pick up speed and things happen quickly then! Being a systemic weed killer, it absorbs through leaves and then circulates to the roots. This process takes time but works.

The trick with Weedol is to follow the instructions carefully. I would almost say it’s turned out to be a downside that it is so versatile. That in itself makes no sense but it seems following the instructions is difficult for some so lets prep you so you make this product work well. It can be used with a pressure hand sprayer or ordinary garden watering can. You want to make sure you use a fine rose if the latter.

Here’s where you need to start following. For a start it needs to ideally be summer months but could be April to November. Personally I get better results, the warmer it is. If the bottle sprayer, add one tube to 1 Litre of water. Then you should aim for about 30 metres squared of coverage on annuals like Chickweed and Fat Hen. If it’s a perennial like Stinging Nettles then expect to get around 20m2 as you’ll need to douse the leaves thoroughly. This reduces still to around 10m2 in my experience with bramble. Basically the hardier the weed, the more the mixture will need to be absorbed through the leaves.

So this is where it gets a little tricky. With a watering can you want to change the ratios completely. This time it is 5 Litres of water per tube. Everything else remains the same. Now from my perspective this is great because it really helps to kill large patches of weeds. Using the watering can is a great way of getting decent coverage on large areas fast. It works brilliantly for gravel areas with weeds poking through annoyingly or ground clearance before your Autumn or Spring dig. I think this is probably a better solution than the review above for larger patches and certainly better than the standard Weedol. I would take Weedol Ultra Tough every time for the tough jobs.

It’s pretty good for children and pets. In fact, it is exactly the same as Roundup. It also contains Pyraflufen-ethyl which is a legal product in the UK but not all of Europe. So it’s considered nasty stuff. But then again it would have to be in order to kill plants…Make sure that it’s bone dry before sending the kids out and you’ll be OK. They recommend allowing 7 days after application for planting but I always like to leave a couple of weeks. In any event, if you have tackled hardy weeds, they may not be dead for a month, so plan the treatment well, then it’ll be no hindrance at all to wait a little to feel more confident about planting, especially if it’s edible! And please, do not forget to wash out your watering can after!

Overall this weed killer is worth its money and works well with good time planning

Pros

  • Kills to the roots
  • Will kill Ivy and hardy bush
  • Can be applied with watering can or spray bottle
  • Strong mixed use weed killer
  • Great on gravel driveways

Cons

  • The versatility leads to confusion in following guidelines
  • Takes a month to see great results on hardy weeds
  • Probably not as effective as Gallup when in stock

Weedol ultra tough weed killer liquid concentrate

4. Doff Glyphosate weed killer concentrate, multi-colour, 1 litre

This has become a reliable product over the years. Well known for its strength and qualities as a systemic weed killer. Although there is only a litre, you’ll effectively treat over 300m2 from my personal experience. The sales pitch is that you’ll get 416m2 but I tend to use it for tough weeds that need re-application a few days later to ensure the leaf is able to absorb enough to get into the plant, right down to the roots.

Generally I use 50-60ml per litre and have no trouble killing weeds off over a period of a few weeks. The lighter stuff will die more quickly than this too. I find the easiest way to apply this is with a portable garden sprayer. If this gets a day drying time after application then I have only had excellent results.

Overall I prefer the Gallup based on value for money but both products work well and this would probably be my second choice as it’s pretty good on Dandelion, Willow Herb, and most grasses.

Pros

  • Kills most weeds and works on Ivy
  • Suitable for gravel driveways
  • Works on artificial grass but do a test patch first

Cons

  • Little bit pricey compared to top pick

Guide to using weed killer

I know this is pretty trivial but the ultimate trick with weed killer is to carefully follow the instructions and BE PATIENT. Almost all systemic weed killers will take a while to work because the Glyphosate is absorbed into the leaf and then needs to travel to root tip in order to completely kill the weed. It will take up to a month but can be quicker and generally depends on the conditions. Never be in a rush and have a timed plan to keep things safe. The longer you leave to plant after application the better and seven days is the minimum.

Best weed killer for driveways and block paving

Based on price, ability to kill weeds, least staining and residue, safety for kids and pets, ease of application, reliability, and customer support, I make my choice looking for the best overall score.

For those reasons, in my experience, the Gallup home & garden glyphosate weedkiller, 2L has this by quite some way with price being a heavy factor. There’s no doubt it works great and probably has the best reviews over the internet as well. To tell you the truth, this probably isn’t that surprising given this weed killer is 360g per litre of Glyphosate. This is on par with commercial strengths and certainly much higher than other quality weed killers like Doff. It stands to reason that it’ll give excellent results.

Given the price differential at the moment it makes it a no brainer that you will be pleased.

Safety first

Before we begin the process of application. It is essential you have a mask, goggles, and gloves. Always wear these and ensure you have tough clothing like jeans and some boots. It is not an exaggeration to talk about how dangerous these chemicals are. You only have to look at what they do to plants….

When you use your watering can or sprayer, ensure you thoroughly clean out afterwards. It’s also advisable to not put remainder down the drain so only mix what you need.

Keep kids and pets away from the garden after application until the weeds are completely dry. Do not cut corners on this, we are talking about a toxic product and the correct procedure needs to be followed in order that it is safe to use. Never take risks when the family is concerned.

Avoid spraying on windy days as this will increase the likelihood of ingestion as well as reduce the amount of product that is absorbed on the leaf. If you spot bad weather on the horizon stop what you’re doing and wait for dry weather.

Ideal time to apply

As with all weed killers, they generally work between March and November. Always check the packaging for specific dates but they should fall within this range. The secret is to apply weed killer in bone dry, hot sunshine. The warmer the better and if there has been no rain for a few days before all the better. Make sure you give yourself the best chance and check the weather forecast. A couple of warm days forecast in advance would be absolutely ideal to produce the most efficient results.

Generally you can use these product damp but it’s not worth it. If you’re going to do it then do it right is where we need to be. This also means don’t clean your drive or patio prior either if you intend to use weed killer. The healthier the weed, the better these systemic weed killers actually work because healthy leaves absorb more toxin basically.

Different types of weed killer

Systemic – this is where you apply the product to the leaf and it is then absorbed and slowly makes its way down to the root and kills the weed so that it will never come back.

Selective – when a weed killer is designed to kill one weed and leave plants intact. This is often the case with lawn weed killers that also act as a feed.

Preventative – you can get weed killers that will stop weeds before they come. These aren’t the best if you are thinking of vegetables or flower beds as you’ll want to use the space at some point in the near future.


About Terry Smith

I’m Terry Smith from gardentoolbox.co.uk, a professional landscape designer, hobbyist gardener, and barbecue fanatic with 20 years experience building and restoring. So as you go through my site you'll watch me document some of the professional garden installs I make as well as the major projects I take on at home. While sharing those experiences and guiding you, I'll be recommending some great tools I use to enable this along the way so you can really buy in confidence.

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