Killing Moss on Lawns

As people start to get back out into their gardens, the most common question among gardeners is ‘How do I get rid of moss and weeds on my lawn?’

March until September is the perfect time to treat for moss. I typically treat my own lawn in March or April and give it a second go then again in September or October. That way, I stay on top of moss and am not left with bald patches on the lawns.

Moss can be a big problem with lawns.
Raking moss from lawns can be hard work.

Best products for killing moss on lawns

I highly recommend Mo Bacter. It is an organic, slow release lawn fertiliser with added magnesium. It contains friendly bacteria that eat moss and turn it into fertiliser. It is quite sensitive to temperature so it must be at least 12 degrees for it to work. Ideally, it should be spread in damp conditions. I would recommend topping your grass about two days before spreading to expose the weeds and again two days after applying the treatment.

Mo-Bacter improves the soil overall and there is no black mess or raking out needed afterwards. The fertilizer contains beneficial decomposing bacteria which consume the organic waste and convert it into useful lawn feed.

One bag does about 100 metres squared, the size of a typical town garden. However do measure your lawn beforehand and spread it at the correct rate. You can spread it by hand, but I have a little push along spreader that does the job in half the time and achieves an even spread.

Mo Bacter takes about two weeks to work and is far better than traditional chemical treatments that will turn your lawn black. It also feeds the grass and doesn’t harm animals or wildlife. All the same, I would recommend keeping pets out of the treated area for at least 24 hours, to allow the product to work its magic.

Many gardeners, particularly those with larger areas to cover, also use Evergreen Extra 4 in 1. It gives you greener, thicker grass, kills moss and kills weeds. It contains a water retention gel and is very popular. One bag treats 400 metres squared. Again, it works best when the temperature has exceeded 12 degrees.

I also recommend adding lime to your lawn every few years. It helps keep moss away; energises the grass and releases vitamins. I do my own lawn about every two years. We sell tester kits so you can measure the pH in your soil and check if a treatment might help.

If you plan to spread lime on your lawn, allow at least two weeks from when you treated it for moss and weeds.

With a little effort you will have a beautiful lawn to enjoy.

Malachy’s top tips for killing moss and weeds on lawns

  • Cut your grass two days before applying the treatment to expose the weeds
  • Only apply the treatment when the temperature has reached at least 12 degrees
  • Keep the treatment away from neighbouring plants, tarmac or hard surfaces as it will stain them
  • Spread on a calm day and when rain is expected within 48 hours
  • Never use in drought conditions
  • Apply twice a year to keep lawns moss and weed free
  • Cut your lawn regularly and avoid scalping it as this exposes the soil and allows moss to grow rapidly

We’re here to help

If you have any questions about looking after your garden talk to any of our horticulturists in store. If you have a specific problem like pest damage on a plant, it’s really helpful to bring us a photo of it. We’d love to help.


All products mentioned in the above blog can be bought on or in you local CountryLife branch. To find your nearest store click here.

Mo Bacter

Mo-Bacter improves the soil overall and there is no black mess or raking out afterwards. The fertilizer contains beneficial decomposing bacteria which consume the organic waste and convert it into useful lawn feed. To achieve the best results it should be applied at 100g per msq and must only be applied in ground temperatures above 12 degrees celsius. Safe to use around kids and animals it does not stain concrete or paving.

Price: €21.99

Easygreen Rotary Spreader

The Easygreen spreader is ideal for using lawn treatments and spreading grass seed on lawns. It has a capacity of up to 10kg and a spreading width of 1.8m. Avoid the heavy lifting of bags or direct contact with garden fertilizers with this spreader. It has five adjustable spreading settings ensuring you get the best coverage from your chosen product.

Price: €89.95

Viano BIO-Lime

Viano Bio Lime is an organic based product which lowers the pH levels (scale used to measure acidity) in the soil to promote healthy thriving grass. By reducing the pH levels it frees up more nutrients within the soil for the grass to uptake and reduces moss development. This can be applied at 50-100 grammes per metre squared all year round.

Price: €21.99