By Nimrod
Bristol U.K.,
United Kingdom 
I have just scarified my lawn with an electric raker and removed a lot of moss but this has left the lawn looking a bit threadbare with traces of moss still present. Should I treat with mosskiller first and then apply fresh grass seed or should I oversow with seed first and apply mosskiller when the grass is more strongly established?
22 Apr, 2013
Answers
Treat with moss killer first.Then scarify. I prefer to scarify in mid September because if you do it earlier and we have a dry spell the grass can look a mess for weeks.
You also need to look at why there is moss in your lawn. It is almost certainly due to bad drainage. Try pushing a garden fork to a depth of 4-6 inches at 6-9 inch intervals.The holes should create better drainage.
23 Apr, 2013
I would go over it again with the scarifier, and then try to cure the reason for the moss, spiking the lawn, either with a garden fork, or hiring an aerator, and filling the resulting holes with sharp sand, and then reseeding any bare patches, you may not have to use any moss killer at all, Derek.
23 Apr, 2013