Moss in Lawn

Moss can look lovely in the right setting; it looks positively awful in the lawn, especially as it dries out and turns brown during the summer months.

If left untreated, it can quickly colonise a lawn, replacing the grass almost completely. This is especially a problem in damp shady conditions.

I don't think I need tell you what moss is. But here's something you might not know:
The time to tackle moss (if indeed you decide to do this) is not in the spring, as most growers suppose (and as most gardening books recommend). No. The time to tackle it is in early autumn (August in the UK) when it recommences growth during the warm dewy nights. At this time it can be nipped in the bud and kept under control.

This is not to say that it cannot be controlled in spring - it can. Modern moss killers will turn it black before your very eyes - literally. It can be killed in seconds. However, as you might be aware, killing it is not the problem; the problem is the unsightly mess that is left behind.

Gardening books tell us to rake this dead moss out immediately. Nothing wrong with this. But unfortunately it leaves a lawn devoid of grass, resembling the leftovers of a nuclear holocaust. And it can look this way for several months until the grass has had time to get going and fill in the bare patches.

Many gardeners think that raking the moss out in this way will prevent its re-establishment. I don't think this is true. I think just the opposite. Disturbing it too much will help spread the spores (the moss's equivalent of seeds) to other uninfected parts of the lawn. These will lie dormant till autumn.

It is supposed that moss killers kill these spores. Not true. As far as I know, only mercuric chloride (the old-fashioned moss killer, no longer available) will kill spores. Ferrous sulphate, the common moss killer, will not.

When we consider as well the enormous effort needed to rake a lawn efficiently, added to the above, I think there has to be a good case for leaving it alone.
This might sound horrific, but it is not so silly as it seems.

Since we cannot kill the spores and prevent re-infection, and since the moss dies out anyway in dry weather, what benefit is there in killing it off in the spring?

Provided it is not too unsightly, and that water can pass through it to the lawn, my suggestion is to leave it alone (and green) for now and concentrate on reviving the remaining grass so that it will be ready to take over as the warmer months approach, filling in as the moss dies back, and subsequently hiding its brown colour. This avoids the unsightly mess. It also saves us much time and effort whilst avoiding adding chemicals to the soil.

The moss will rot down in the turf as it dies back, leaving the grass. Then we can tackle it when it resumes growth in August. Hopefully, by that time we should have a decent lawn.

That's the theory, anyway. I have used this principle for several years. It has worked well for me. I hope it will work for you.