[AlaninCarlisle]

I've got quite a large front lawn at about 1000 sq metres. I treated it to within an inch of its life with Iron Sulphate and intensive scarifying followed by some re-seeding this Spring and it has looked great ever since. That is until I cut it this afternoon when I noticed the tell-tale bright green of the moss starting to return. I've just called the local farm-supplies depot and their advice was to leave it until Spring and then to get busy again with the iron sulphate.

I doubt that a greenkeeper or groundsman would take such a laissez faire attitude and I wondered if anyone on here has any advice, please

[Kristen]

Aerate, preferable with hollow-tine coring machine, and collect up the cores, and then brush sharp sand in (they say to brush it into the holes, but that's not really possible! just let the rain wash it into them, but you do need to brush it into the grass).

That should improve the drainage, and make the moss's life harder.  Sounds like you have had a dry summer and that has kept the moss in check ... and now we've had some rain its making a comeback, and I think better drainage would help.

You'll still need to kill the moss, but I would start once it has got a foothold, rather than waiting for spring.  I had a lot of success with Iron Sulphate applied mid winter last year (dreadful wet summer last year, so my moss was a lot worse than normal) and come spring there was not much of it to be seen

[AlaninCarlisle]

Thanks Christen, I'll take your advice and hire a hollow-tine machine and do the entire 1000 sq metres. How much sharp sand do you reckon I should buy? Is it a case of a few 20kg sacks or a 1 tonne builder's bag?

[Kristen]

A 1 tonne builders bag on 1,000 sq.m. will be 1mm deep ... not enough I think.

You might want to read this to diagnose before embarking on adding sand.  If you are on heavy soil, and it is likely to be compacted, I think aeration and sand is a good start. If you have poor drainage (particualrly if you get standing water on the lawn after heavy rain) then I think you should consider land-drains first.

This site doesn't favour aeration and sand, although I disagree! but this article does cover other possible causes:

http://www.lawnsmith.co.uk/enthusiast/moss-control-for-enthusiasts/lawn-care-vs-lawn-moss-part-1

[jezza]

hi i was taught to scarify lawns spring and late summer early autumn it never harmed them use sulphate of iron or mix your own lawn sand spring mix is 3partsb by bulk ofammonium sulphate 1 part by bulk iron sulpate 10-20parts of dry inert carrier such as sand ,summer autumn mix use phosphate and potash 1part by bulk  then scarify and hollow tine if on sand let cores dry then rub back in with a lute or back of rake if on clay remove cores then mix equal parts top soil and sandrub well in one shovel full to a square yard   jezza

[Kristen]

rub well in one shovel full to a square yard

I think if it hasn't been done before / recently, and is heavy soil and compacted, I would go for quite a lot more than that, what do you think?

Whereas for a regular top dressing then a light covering, one shovel full to a square yard as you say, would do the trick