Moss killer buying guide

Moss Killer & Ferrous Sulphate Buying Guide

Which moss product is the best one for me?

Please note that killing moss is only half the job. The other half is growing a better, stronger and denser lawn. This means grass health is equally important.


Use Winter Green High Iron or Evergreen Mosskil. This is a granule applied through a spreader. This also has a low nutrient content and is ideal as a cold weather winter feed, which will promote very little grass growth. It is not a substitute for an Autumn or Spring feed due to its very low nutrient content


Use Green-up Ferrous Sulphate. It is very cost effective when mixed with water and applied by a sprayer or watering can. This is also the equivalent of a vitamin and will green the grass, but it is not food! It can be used regularly and has other beneficial effects on the lawn and soil.


Use either Green-up Ferrous Sulphate, Winter Green High Iron or Evergreen MossKil. All contain ferrous sulphate which greens grass and the last two also have a light nutrient content.


Use MossOff. Chemical free and safe for children and pets. It won't mark your patio or paving; all the others need to be kept off hard surfaces or brushed or washed off. Please see the Q&A's bottom of the page for more safety advice.


Use MossOff. Once MossOff has dried, it forms an invisible micro-coating that is durable and not affected by rainfall and continues acting preventing moss growth for a long time.


This is by no means fixed so be prepared to be flexible depending on your preferences and the severity of moss. The plan can be started at any point and requires a full 12 month cycle to maximise effectiveness.



  • use Winter Green once to feed, control moss and maintain grass health
  • any moss recurrence should be controlled with either MossOff or Green-up Ferrous Sulphate


  • 2 weeks prior to raking moss apply your preferred product - usually late March onwards for southern England and April onwards for everyone else
  • Rake moss out then apply a second treatment of either MossOff or Green-up Ferrous Sulphate - a 4 week gap is required if using ferrous sulphate twice
  • After 2-3 days if using ferrous sulphate or 7-10 days if using MossOff you may need to rake lightly again prior to over seeding
  • Over seed - this fills in the gaps before nature fills them in with dandelions and also re-populates the lawn with new grass strains
  • Apply Spring Fertiliser at the time of seeding. Use either: Spring & Summer for Sandy Soil or Natur


  • Moss may re-occur during cooler wetter weather so use either: MossOff or Green-up Ferrous Sulphate to suppress
  • If you need to scarify and there is moss present, follow the plan for Spring
  • Always apply an Autumn fertiliser

FOLLOWING YEARS - maintenance programme

The YEAR 1 programme should bring you back to a healthy, grassy rather than mossy lawn. If your lawn starts reverting rapidly back to moss something is causing this. It is either the conditions surrounding your lawn or your mowing needs adjusting. Read more here.


  • use Winter Green once to feed, control moss and maintain grass health
  • any further moss recurrence should be controlled with either MossOff or Green-up Ferrous Sulphate


  • 2 weeks prior to feeding apply MossOff or Green-up Ferrous Sulphate
  • Apply Spring Fertiliser


  • For suppressing moss if present during the cooler wetter weather use either MossOff or Green-up Ferrous Sulphate
  • If you need to scarify and moss is present, follow the plan for Spring in Year 1
  • Always apply an Autumn fertiliser

View Moss Killer Products

Common Q&A's

Are these products safe for children, dogs and cats?

If you wish to feed and kill moss at the same time then Winter Green Fertiliser allows the lawn to be used after application though it can stain feet up to 72 hours after application.

If our Soluble Fertiliser or Green-up Ferrous Sulphate is used then the lawn is safe once dry. This would take just a few hours in the warmer months. Ferrous sulphate may stain feet within the first 24 hours of application.

If you have any concerns then use MossOff as this is completely safe and doesn't stain either.

Unlike grass ‘weed and feed’ products, Lawnsmith® Granular Fertilisers do not contain pesticides or weed killers. Though the bag of bulk material should be stored safely away from children and pets, the lawn is safe for use by children, wildlife, dogs and cats immediately after application.

For weed killer we suggest you use one of our liquid products as the manufacturer’s recommendations are that once dry they are safe.

Finally, some pets have some peculiar idiosyncrasies, therefore, if you feel your pet may consume or is sensitive to these products then keep them off or don’t use the product.

Lawn products where pets graze or forage (rabbits, hens, ducks etc)

MossOff can be used where animals graze as it is chemical free and contains only natural substances.

For all other moss control products we suggest grazing animals are better kept off for 3 mowings. Ferrous sulphate products may stain feet within the first 24 hours of application./p>

Finally, pets do have some peculiar idiosyncrasies so if you feel your pet is likely to consume or is sensitive to these products then keep pets off or don’t use the product.

When can I apply to moss in the lawn?

  • Anytime after mowing
  • At least 3 days but preferably 5-7 days before next cut
  • Avoid strong sun, frost and freezing
  • Give a 7 day gap if using weed killer (before or after)
  • If seeding give a 3 day or more gap between application of these products and spreading seed.

Can I mix ferrous sulphate with other products?

Ferrous Sulphate can be mixed in the same container as our soluble fertiliser. You can also apply ferrous sulphate at the same time as applying granular fertiliser.

Do not mix weed killer with moss killer or ferrous sulphate. If you need to kill moss AND weeds do it about a week apart.

When seeding, you can spray ferrous sulphate on the lawn 1- 2 days before spreading grass seed.

How often can I use these products

Green-up Ferrous Sulphate

This can be used as a greening agent throughout the year at a low rate of 0.5 to 1 gram per square metre. You can apply every 4 to 6 weeks as many times as you like.

If you are using it as a turf hardener to improve disease resistance at 2 grams per metre then you are only likely to do this once or twice a year in mid and late autumn.

The main use is as a moss treatment at 4 to 5 grams per metre. This can be done every 4 to 6 weeks from late autumn to spring. We suggest no more than 3 applications at this rate in any one year.

Winter Green Fertiliser

This also contains ferrous sulphate and has the same blackening effect on moss. Because it also contains other nutrients we recommend no more than 2 applications in winter or early spring spaced 10 or more weeks apart.


Can be used as often as required

Will it stain hard surfaces?

MossOff is the only moss control product that will not cause staining. If you use any of the others ensure your brush or wash off patios, decking or paths immediately.