Fast Acting Moss Killer for Lawns - Iron Sulphate


(6 customer reviews)

10% off when you spend over £60 – use code ’10off’


  • Use 2-3 times where moss is present during Autumn & Winter or Spring to kill moss and bring your grass back
  • Kills moss on lawns fast by turning it black
  • Makes grass grow better and become greener
  • Immediate, fast acting results
  • Soluble and easy to apply with watering can or knapsack sprayer
  • Excellent results when used for moss control and moss removal on garden lawn


Our moss killer is formulated to kill moss on your lawn, while making the grass greener in colour.

When & Where to use moss killer for lawn

For best results, you should use this product to remove moss and improve the colour of the grass blades before you rake or scarify the lawn

Apply during Spring, Summer or Autumn when the weather is not too hot and not too cold. Don’t apply if frost is forecast.

It’s perfectly fine to apply moss killer at any time of year but you want to make sure the grass is growing well when you scarify.

The best time to apply this product early in the growing season – March or April – as part of a year round lawn care programme.

When to expect seeing results from ferrous sulphate moss killer for lawn

The fast acting formula will blacken moss within 2 days. After which, you should rake or scarify the dead moss from the lawn.

The grass will turn greener over the following 2 weeks

How to apply moss killer on your lawn

The simplest method is by mixing the granules with water and sprinkling the mixture over a marked out area on the lawn. There are 2 popular methods of applying iron sulphate to lawns. One is with a watering can and the other with a knapsack sprayer.

When you receive your moss killer, you will also receive full instructions on how to correctly apply the mixture for best results

How much moss killer to use

How much iron sulphate to use with a watering can

For moss control hen using a watering can, you will need 4 grams per litre of water and 1 litre of water will cover 1 m2.

For example, if you have a 10 litre watering can, that’s 40g mixed with 10 litres of water, sprinkled over 10m2.

How much iron sulphate to use with a knapsack sprayer

For moss control when using a knapsack sprayer, you will need to mix 4 grams of iron sulphate with 200ml of water to cover 1m2.

For example if you have a 16 litre knapsack sprayer, that’s 320g mixed with 16 litres of water to cover 80m2.

Knapsack sprayers have finer nozzles so they can apply the right amount of product without needing as much water

For more information, read our full article on ‘how to get rid of and prevent moss in your lawn

Is Iron Sulphate safe for pets and children

As this is a non-toxic product, it is safe to use where pets and children play. However, iron sulphate is known to stain surfaces. So, it’s recommended to keep pets off treated areas until it has been properly absorbed by the lawn – usually a couple of days or after a heavy downpour. That way it removes any possibility of their fur being stained by the product.

To find out more about which products you should take precautions with, read my article ‘Is lawn feed & fertiliser safe for pets and kids


Additional information

Coverage (m2)

100m2 (400g), 200m2 (800g), 300m2 (1.2KG), 400m2 (1.6KG), 500m2 (2KG), 600m2 (2.4KG), 700m2 (2.8KG)

Techie Specs

Ferrous Sulphate of Iron Analysis

NPK : 100% Fe

100% Iron will blacken moss and green-up the lawn

Season for application: Spring / Summer / Autumn

Soils to use on : Loam, Chalk, Sandy, Clay

Time feeding : 1-2 weeks (takes effect immediately)

Apply with : Watering can or Knapsack sprayer

Nutrients: Ferrous Sulphate of Iron

Type / Size: Soluble Granules (always dilute with water)

6 reviews for Fast Acting Moss Killer for Lawns – Iron Sulphate

  1. Francis

    It’s the best I’ve tried. Killed the moss and helped the grass

  2. Naomi

    This is what I’ve needed for the last 5 years. Amazing stuff!!

  3. DT

    Decided to go for the premium stuff to kill the moss in my lawns. I put it on near the end of January and did not know how much it would work. Mixed in a watering can and used it to cover the area. Due to it being a bit cold did not expect much. Within 7 hours the moss was black and started to shrink. The grass also took on a greener look. I can highly recommend it’s purchase. The product is good value for money and very pleased with the immediate results. Very happy so far.

  4. Mark P

    Very fast acting made the grassed areas turn deep green as well

  5. Steve Cooper (verified owner)

    Fast acting is right! I didn’t expect to see the discoloration while I was still treating the lawn!
    I’m not a gardener, but this was easy and I’m well chuffed I picked this stuff 😁

  6. Mark t (verified owner)

    Fantastic stuff I used it in spring got rid of all the moss and greened up my lawn I’ve bought lots more for the autumn
    Dead easy to water in and really cheap
    I have two medium lawns only costs about £3 to treat them both

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