The Best Weed Killer For Lawns

Written by Daniel Woodley. Reviewed by Elizabeth Smith. Published to Lawn Care on 28th August 2022. Updated: 22nd February 2023.

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If you want a lawn to be proud of, at some point you’ll need to take action against invasive weeds.

After years of growing a lawn and helping others, I’m confident I have a solution.

I apply two different weed killers, one in the spring and the other in the autumn.

This is sufficient to suppress weed growth, leaving space for the grass to thrive.

While there are hundreds of different species of weeds and invasive plants, I’ve found that just these two products are enough for treating lawns.

This is my review of Weedol and Greenforce lawn weed killers.

I Tested Weedol. This is What Happened:

In June 2022 I tested Weedol concentrate on three common garden weeds. I mixed the recommended amount of Weedol with water and sprayed the foliage lightly, minimising wastage.

Here are the results:

(Please ignore the brown grass, this is due to a drought and hosepipe ban here in the UK)

Test 3

As you can see from the results, Weedol didn’t kill the weeds instantly and in test 3, there was little difference from day 1 to day 7 – the weeds had even started to grow faster, albeit twisted.

By day 14 the weeds in test 1 and 2 were all dead and in an advanced state of decay. The weeds in test 3 took al little longer to die off.

Update August 28th 2022 – none of the weeds has grown back since I treated them in June.

FYI: Weedol contains Fluroxypyr, Clopyralid and MCPA.

The Weedol Product I Used

Weedol produces several different weed-killing products. This is the one I used:

I chose this product because it comes in concentrated form and once diluted, one 250ml bottle will produce 85 litres of weed killer.

I feel this is far more economical than buying ready-to-use bottles that only treat small areas.

Concentrated Weedol works out at about 18p per litre, once diluted, which is a bargain.

I also have experience with this product and have been using it for years.

Cons

• I had to dilute it so that means handling chemicals.
• It doesn’t come with a measuring gauge, so I had to measure it myself.
• It doesn’t come with a built-in sprayer, so I had to use my own sprayer.
• As with all chemicals, I had to keep pets and children off the grass until it had dried.

If Weedol’s Weed Killer Doesn’t Work

I’ve been using Weedol for years, and from what I can tell, it will kill around 99% of broad-leaved weeds that grow in UK lawns, but in my garden it didn’t kill every weed.

Greenforce is an alternative product that contains different chemicals:

Mecoprop P at 3.67%w/w

Dicamba at 4.657% w/w

If you have weeds on your lawn that don’t respond to Weedol, I’m 100% sure that Greenforce will deal with them.

This is why I use Weedol in spring and Greenforce in autumn – they contain different chemicals, and by using them both each year, I’ve been able to kill off all the weeds in my lawn.

I Tested Greenforce’s Lawn Weed Killer. Here are the Results:

In July 2022, I applied Greenforce concentrate to a patch of overgrown brambles, stinging nettles and other weeds in a corner of our yard.

I also sprayed it onto the grass, some nearby bamboo and close to some conifers.

Here are the results as of the 28th August 2022:

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As you can clearly see, the nettles and weeds are dead and the bamboo and conifers in the background are unaffected.

I’ve used Greenforce in the past and based on my experience, it isn’t quite as effective as Weedol (it doesn’t treat as many weed species), but as it contains different chemicals, it will finish off any weeds that Weedol failed to treat.

Weedol is my number one choice, but for those with a real weed problem, I suggest treating the lawn with Weedol in the spring and Greenforce in the autumn.

What I Like About Greenforce:

Cons

• The chemicals aren’t as effective as those found in Weedol, based on my experience (I suggest trying Weedol first).
• It doesn’t come with a built-in sprayer so you’ll need to buy one or use a dedicated watering can.
• As with all chemicals, you’ll need to keep off the lawn until the product has dried.

To Remove and Prevent Lawn Moss:

None of the lawn weed killer products listed above are effective against moss.

Based on my experience, if you want to remove and prevent lawn moss, there are only two products I think you should choose from:

1. Bacteria that eats moss (often called “No Rake” moss killers).
2. Iron sulphate.

I have already written about these products, how to use them and what results I’ve experienced:

Read my guide to lawn moss removal and prevention.

My Experience with “All-In-One” Lawn Weed Killer Products

All-in-one lawn products contain a bit of everything:

• Fertiliser.
• Iron sulphate to control moss.
• Weed-killing chemicals.

Based on my experience, “all-in-one” products are perfect for maintaining an existing lawn but they don’t contain enough of each chemical to treat lawns with severe problems.

Once you’ve used a dedicated product to get rid of a nasty weed infestation, you can use the cheaper “all-in-one” products to keep it under control and stop it coming back, but from my testing over the years, I feel that’s about all they are good for.

My Test of Manual Lawn Weed Puller Tools

In 2022, I tested two manual weed puller tools:

• An upright weed puller by Fiskars.
• A simple hand tool that yanks out the roots.

If you would like to try the chemical-free method of getting rid of lawn weeds, explore my review of the best puller tools.

Lawn Weed Killer FAQs

Step-by-Step Guide to Removing Lawn Moss

Remove and prevent lawn moss with our insightful step-by-step guide which also includes organic and chemical-free suggestions. Start Here