The first question is where the moss actually is: in the lawn itself, or on a hard surface such as a patio, drive or path. Treating a lawn with a hard-surface product, or the other way round, wastes money and can damage the surface you are trying to fix.

Moss in the lawn: organic and indirect, or fast iron blackening?

MO Bacter takes the slow, indirect route. It is an organic lawn feed, 5-5-20 plus 3% MgO, with the naturally occurring bacteria Bacillus sp added, that overfeeds the moss on potash until the plant breaks down from within. There is no need to scarify beforehand or rake anything out afterwards: the moss turns light brown over 14 to 21 days, then disappears gradually into the thatch layer as bacteria digest it into plant food. It will not stain paths or patios, and it is safe around children and pets.

MossOff Lawn Care is a similarly gentle option, a non-biocide formula safe around ponds, pets, children and plants, that will not scorch the grass. A 5 litre bottle makes up to 30 litres of solution, covering up to 210m² at the lighter dilution or 140m² where moss cover is heavier.

Where the priority is speed rather than a gentle approach, Black & Green combines 12% iron with 5% magnesium oxide, blackening moss quickly even at normal application rates while the magnesium drives a fast green-up in the surrounding turf. It can go down at any time of year provided the ground is frost-free, with each application lasting around 4 to 6 weeks. Iron products like this one can stain hard surfaces, so keep granules off paths and patios and sweep up any spillage.

Where moss and broadleaf weeds are both a problem on the same piece of turf, Sportsmaster Renovator Pro is a triple-action granular product: a compound fertiliser, three selective herbicides for weeds such as cat’s-ear, creeping buttercup and daisies, and iron for moss control, all in one application between April and September.

Moss on hard surfaces

Patios, driveways, roofs and paths need a different kind of product, since a lawn treatment will not do much on a non-porous surface. MossOff Multi Surface, MMC-Pro and N-Virol all treat moss and algae on hard landscaping; the fuller comparison between them, including HSE approval status and dilution rates, is covered in the hard surface cleaners guide.

Which product for which job

General lawn moss, no rush, and want to avoid scarifying: MO Bacter. Lawn moss with pets or a pond nearby: MossOff Lawn Care. Moss that needs to go fast, on turf that can take iron: Black & Green. Moss and weeds together on sports or amenity turf: Sportsmaster Renovator Pro. Anything on a patio, drive, roof or path: see the hard surface cleaners guide.

Moss usually points to an underlying condition, shade, compaction or poor drainage, that a one-off treatment will not fix on its own. Treating it is worth doing alongside a look at why it took hold in the first place, or it tends to come back the following season.

Frequently asked questions

Will moss killer stain my lawn, patio or paths?

Iron-based lawn treatments such as Black & Green and Sportsmaster Renovator Pro can leave rust-coloured marks if granules land on paving, so keep them off hard surfaces and sweep up any spillage. MO Bacter and MossOff Lawn Care are organic, non-biocide formulas and will not stain paths, stonework or patios.

Do I need to scarify or rake out the dead moss afterwards?

Not with MO Bacter: its potash content breaks the moss down from within, so it disappears gradually into the thatch layer rather than turning black and needing to be raked out. Iron-based treatments such as Black & Green blacken moss quickly, and the dead material generally needs raking out once it has turned, or it will sit as a layer of dead thatch on the surface.

Can I treat moss and weeds in the lawn at the same time?

Yes, with Sportsmaster Renovator Pro, a triple-action product that combines a compound fertiliser, three selective herbicides for common broadleaf weeds, and iron for moss control and green-up, for use between April and September. Where moss is the only problem, a moss-only product such as MO Bacter or Black & Green avoids putting herbicide down where it is not needed.