Fast Acting Iron Sulphate (for Moss-ridden Lawns)

Our iron sulphate is formulated to improve your lawn, while making the grass greener in colour. It will also blacken moss ready for scarifying.

This iron sulphate has undergone rigorous tests. It’s the easiest to use based on its ability to dissolve quickly in water and never clog-up your watering can, knapsack or boom sprayer.

When & Where to use iron sulphate for lawn

For best results, many people use it to kill off moss and improve the colour of the grass blades before you rake or scarify the lawn

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

It’s perfectly fine to apply iron sulphate 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 iron sulphate for your lawn

The fast acting formula will blacken moss within 2 days. After which, you should rake or scarify the dead moss from the lawn. You could do a second application after scarifying if you wish but its not absolutely necessary

The grass will turn greener over the following 2 weeks

How to apply iron sulphate on your lawn

For medium sized lawns, our 2L pump sprayer is the best way to mix iron sulphate with water and apply it to your lawn – see below for ratios.

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 iron sulphate, you will also receive full instructions on how to correctly apply the mixture for best results.

How much iron sulphate to use

How much iron sulphate to use with a watering can

For moss control when using a watering can, you will need 4 grams per litre of water and 500ml 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 3-4 grams of iron sulphate with 100ml-200ml of water to cover 1m2. Don’t go lower than 100ml of water.

Knapsack sprayers and boom sprays that have finer nozzles 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‘