Written by Terry Smith

Our site is reader supported so when you click a link to Amazon we may earn an affiliate commission.

Best Organic Weedkillers Reviewed UK

This article was last updated on August 7th, 2021 at 3:39 am

Weeds, the archenemies of all gardeners near and far. We are locked in a constant battle with these invasive plants, trying to stop them from stealing the important nutrients needed for our favourite crops, shrubs, and flowers to grow healthily. The most effective way to get rid of these garden invaders is to use a strong weedkiller, but unfortunately most of these contain harmful chemicals that are not only bad for the rest of your garden, but can harm your pets, children, and even yourself (unless you used pet friendly weedkillers), if you are not careful with them. This is why there are an increasing number of products on the market that are free of glyphosate; one of the main toxic ingredients of regular weed killers. These new organic weed killer products aim to be a safer way to get rid of weeds, and are becoming more and more popular, so we thought we’d take a closer look at them for you.

Comparison table: Best Organic Weedkillers Reviewed UK

ProductWhat We ThinkPrice

WeedKil Glyphosate Free Weed Killer 1 Litre - Child & Pet Friendly

  • ✔️ GLYPHOSATE FREE FORMULA: If you've been looking for a weed killer that is organic...
  • ✔️ECO-FRIENDLY, NATURAL, ORGANIC WEED KILLER: Weedkil works in low temperatures and can be used all year round...
  • ✔️ EFFECTIVE ALL YEAR ROUND: Our home & outdoors weed killer contains 60g/l aecetic acid...
  • ✔️ HOW TO USE: Ideally spray in spring and repeat as necessary over the growing season | Apply on...

Neudorff 613818 WeedFree Plus Concentrated Weedkiller

Neudorff 613818 WeedFree Plus Concentrated Weedkiller 1020ML

  • Long lasting effect against regrowth of tough weeds.
  • A complete herbicide for both weeds and grasses
  • Works against problematic weeds such as goutweed
  • Effective at low temperatures and biodegradable
  • Suitable for use in gardens and on allotments

Glyphosate-Free Powerful Weed Killer

  • Naturally breaks down in soil Visible effects in 3 hours Ready to replant after 3 days Child safe trigger...
  • No Glyphosate* No Glyphosate claim is provided to help distinguish from other formulas that may contain glyphosate...
  • Weed Control

Roundup for Lawns Weedkiller (No Glyphosate)

  • Kills the roots so weeds don't come back
  • Children and pets need not be excluded from treated areas (once dry)...
  • Weedkiller for lawns

Algon Organic Path and Patio Cleaner Concentrate

  • Organic Cleaner - Safe for children
  • 1 x 2.5L Concentrate will clean approximately 60sqm when applied with a garden sprayer...
  • There is no need to rinse off later
  • “ My pale cream limestone patio has returned to its original pristine state from just one application of Algon”...
  • “ It is a safe and environmentally friendly product with fantastic results...

First up is Weedkil glyphosate free weed killer. This organic compound that works wonders on weeds under 10cm tall, and does so pretty quickly too under the right conditions. In place of glyphosate, this company has included 60g/l of acetic acid, which is an ingredient found in vinegar, and one known for being an effective weedkiller.  

It is made in the UK, and so it has been manufactured under strict standards. After spraying this organic weedkiller, you don’t have to wait for long for it to dry up; around 20 minutes, and then after another 24 hours, you can visibly see this stuff going to work as your weeds turn brown and wilt.

Not only for use on weeds, this product can be used as a pet friendly way to clean moss off your patio or driveway too, and again Weedkil’s organic weed killer does a good job of it considering there are no harmful chemicals in it.

Temperature changes won’t affect the weedkilling performance of Weedkil’s solution, so you can use it all year round, but like all of these products, rain and dilute and wash it away before it has time to work properly, so be sure to pick dry spells when you use it.

It is designed to be used both outdoors and inside, and is perfectly safe to do so, but be aware that there is a smell to this stuff. It isn’t overly strong or unpleasant, but it isn’t exactly fragrant either. I have smelled much worse organic weed killers, if that is anything to go by.

A very versatile organic weedkiller, this Roundup Naturals product can be used all over the garden, from flower beds and vegetable patches, to patios and gravel. It is available to buy in 1 litre, 3 litre, and 5 litre containers, with the larger bottles coming with their own free spray wands for applying the solution. The 1 litre bottle is a standard spray bottle.

What I like about Roundup Natural organic weedkiller, is that after just three hours the product will not be washed away by the rain, and this reduces the frequency in which you have to reapply it in order for it to kill weeds effectively. This also means that you use less of the product, so it makes sense economically too. So, does it work? I have to yes, it does indeed, and performed well against a wide range of weeds including black nightshade, clover, and many more. It is also fast-acting, and I could see it taking effect well before 24 hours had even passed. What’s more, it breaks down naturally and quickly into the soil, meaning you can replant in the treated area within just a few days, perfect for places where you need to reseed quickly.

One of the main ingredients in this organic weedkiller is pelargonic acid, a naturally occurring fatty acid found in many things, from fruit to animal’s milk. This acid is a very effective herbicide, but it does perform much better in warmer temperatures than cooler ones, so that is something to be aware of. Under perfect conditions though, you can expect to see this stuff working within just a few hours.

At first glance, you might think the 19.99 price tag seems a little steep for just over a litre of organic weedkiller. However, then you realise that this is concentrate and that once you’ve diluted it, you actually get a lot of product for your money. All the diluted solutions in the world wouldn’t be any good if it was ineffective though, but thankfully that is not the case with Neudorff’s offering. In fact, this stuff is fantastic and will take care of stinging nettles, doc leaves, dandelion, and just about any other weed you can think off.

It works incredibly quickly in warmer temperatures too, with visible results shown on the sprayed leaves within a couple of hours in some cases, and fully dead weeds within 24 hours, ready to be pulled out.

That’s not to say you can’t use this organic weed killer in cooler temperatures, and it will still work down to a couple of degrees Celsius, it’s just that as a pelargonic acid based product, it’s the warmer the better as far as results are concerned.

Neudorff claim that this will work just as well on moss too, but we didn’t get chance to test that out. Nor did we have enough time to find out if the claims of destroying the deep roots were true, but if the way it decimated even tough weeds like horsetail is anything to go by, I would guess it would have a pretty good go at it.

It’s not just our flower beds that have their weed-related problems, it’s very common to see our lawns sprouting up with dandelions, daisies, and all sorts of other weeds too. To make things even more difficult, you can’t just throw any old weedkiller on there either or you’ll seriously damage your lawn. To deal with this specific issue, you need a weedkiller that is made intentionally to work on lawns, and that’s just what Roundup has brought us with this handy product.

This glyphosate free, pet friendly, solution needs only to be sprayed on the weed’s leaves and it will quickly go to work, ridding you of those annoying lawn based weeds in no time, and getting down to the ‘root’ of the problem. You have to use this on an established lawn though, so if you have just laid or seeded a new one, you’ll need to wait around 6 months before you can use this product. 

It is also advised that you only use Roundup for lawns once per year, meaning that if you don’t get the results you were hoping for, you can’t just apply some more or you’ll end up making things worse.

Containing fluroxypyr, clopyralid, and MCPA, you can’t really say this is 100% organic, but as it doesn’t contain glyphosate and is not harmful to pets once it’s dried, I thought I’d add it to the list.

5. Golden Swan White Vinegar

As we mentioned earlier, a lot of organic weed killers contain acetic acid as one of their active ingredients. However, if you want a bit more control over how much of that acid you want to use, you can always buy some white vinegar and dilute it yourself.

Although it is a natural product, white vinegar is a non-selective weedkiller and will damage any other plants that it comes into contact with, so you’ve got to be careful where you apply it.  For this reason, I wouldn’t recommend using a powerful sprayer with it, and to get quite close to the weeds if you do choose to spray.

Used correctly, white vinegar is a very effective organic weedkiller, usually ridding you of whatever you treated within 24 hours.

In addition to this, it breaks down nicely in the soil and won’t cause damage, as long as you don’t use it too often or the salt content can build up.

The downsides to using white vinegar is that it doesn’t really get down to the roots so you have to apply it multiple times (but not more than every two weeks), and it also has a strong smell, making it not exactly ideal for indoor applications.

In the end, using a white vinegar solution as an organic weedkiller can be very effective and cost efficient, and this Golden Swan variety is certainly a good deal. It also has a long shelf life, both unopened and opened, so you don’t need to be in a hurry to use it all.

Moss and algae might not technically be classed as weeds, but I think for most people they are no different and are something they need to get rid of. Algon is an organic weed killer that is designed to clear your garden path, patio, and driveway while remaining safe for your pets and kids to play in the area almost immediately. 

All you need to do is dilute the solution in water in a 1:3 ratio, use a sprayer to apply it to your chosen area, and scrub it in with a brush. You don’t even need to rinse it off. After a few days, you should notice the treated area looking cleaner and the green organic material dying off.
Like a lot of acetic acid-based weedkillers, you need to keep an eye on the weather or this will get washed away and become useless, leaving you to start again. But if you choose your days right and it gets to dry in, the makers of this product claim it will last for up to a year, depending on the surface you applied the solution too and a few other factors.

Algon can damage your plants, so you need to be careful of run off, and it’s probably a good idea to cover nearby beds and borders when using it.  It does do what the company claims though, and we did see some marked improvements on the patio we treated.

The only real gripe I have about Algon is the same I have for the vast majority of acetic acid based organic weed killers: they smell quite strong. Unfortunately, this isn’t really avoidable with these products so it’s something you have to put up with in order to be more eco-friendly.

Algon Organic Path and Patio Cleaner Concentrate

Best Organic Weed Killers Buyer’s Guide

If you still can’ make up your mind about which organic weed killer you want to buy, you might want to read this quick buyer’s guide. It might be just the thing you need to finalise your decision.

Size of the container

Some of these organic weed killers come in a variety of sizes from a single litre, to very large containers/pot. Others, however, are only available in a single size. Why does this matter? Well, for a couple of reasons. 

Firstly, these products have a shelf life and won’t be effective forever, so if you buy a huge container full, but only use a little, you might end up having to throw most of it away, and that’s a waste of money. 

Secondly, if you really like a product and want to use it in a large area, but it’s only available in small bottles, it might end up costing a lot as you will be paying for the packaging to a large extent. Finding the right balance for your intended purposes is key to getting value for money.

Type of organic weedkiller

There are products that are better suited for certain purposes, such as ones for lawns, or patios. Most organic weed killers can be used for a variety of purposes, in different parts of the garden, but be sure to check before you buy just in case.

Will you be using it outdoors, or in the greenhouse?

Organic weed killers can be quite smelly, particularly if you’ve gone with acetic acid as an ingredient, or even with vinegar itself, and this might be too unpleasant for some people if they are going to be using it in the greenhouse.

Another thing to consider, is that temperature can change the effectiveness of some organic weed killers, with colder temperatures that are found outside in winter being not the most ideal for most. Having said that, there are certain products that will still work well in colder months outside.


That’s all for today I’m afraid folks. We hope you enjoyed the article and found it helpful. Please check out our other pages if you have time.

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. Always feel free to pop me a message: info@gardentoolbox.co.uk

View all posts by Terry Smith

Leave a Reply

Your email address will not be published. Required fields are marked *