What Kills Moss on a Lawn Permanently?

What Kills Moss on a Lawn Permanently?

Ferrous sulphate is the quickest, most versatile and cheapest moss killer for lawns. A bit like the common cold though, moss will always come back if the conditions are right!

The following products all kill moss in the lawn. Where moss is quite deep penetration of the moss killer may not go deep enough to kill all the moss therefore it is often best to remove as much moss as possible then kill what is left. That way you’ll kill at least 95% which is about as good as you’ll ever get. Unfortunately, no moss killer kills the spores so good lawn care is ultimately the best moss killer!

Ferrous Sulphate Products (Fe)

Will kill moss in just a few hours and come in a variety of guises as follows:

Dry Ferrous Sulphate Products For Diluting and Spraying

These products are the cheapest moss killers and are also useful to green the grass, harden against winter diseases and reduce worm casting

  1. The Lawnsmith Green-up Ferrous Sulphate is such a product and is a very fine free flowing granule easily measured and dissolved in water
  2. A similar product variant comes as blue granules but becomes sticky and therefore sometimes hard to measure accurately

Liquid Ferrous Sulphate Products

There are many on the market and they still need to be measured and mixed just like the dry product. The procedure is very similar but the liquid is considerably more expensive, takes up more space to store and is only marginally easier to mix.

Granular Ferrous Sulphate Products with Fertiliser

Once again many variations exist with some even containing weed killer. As weed killing and moss killing are usually done at completely different times of the year this can put unwanted chemicals into the lawn. Keep it simple with Lawnsmiths Winter Green which is perfect for application by spreader in the cooler winter months giving deeper penetration into the moss than with liquid products.

Lawn Sand

This is ferrous sulphate mixed with sand rather than fertiliser. Not easy to apply and best left to those with the right spreading equipment. It burns quite deeply into the moss but can also burn the lawn if not applied evenly or in the right conditions.


A unique product applied as a liquid and available in our shop. It is more expensive than ferrous sulphate but has a residual effect lasting a few months. It is also safe around children and pets so certainly worth paying a little extra for if you value those qualities.

Moss Eaters or No-rake Products

These are DIY products that kill and decomposes the moss so should in theory not require moss to be raked out.

Though reliability is an issue the biggest downside to these products is the time it takes for them to work. This can easily be many weeks so if you have a fair bit of moss and you're waiting to over seed the lawn you may well miss the perfect opportunity and end up trying to seed in a dry period!

Home Brews

Mixtures containing soap, vinegar and other household chemicals can kill moss but not on the lawn please.

Improve your Lawn Care

Prevention can be easier and cheaper than a cure so if you want to know more about controlling moss then read the other pages in this section plus visit this topic

Lawn Moss Control & Removal