On 11/03/2021 20:10, David wrote:

The weed and feed says treat in May but the lawn is already growing
strongly.

I'd wait and see if a warm spell is forecast. If it is then go for it.
I cut mine 1st March since it was getting very long.

I'd like to kill off some of the moss early in the year to give the grass
a chance to grow through before it gets too hot and dry.

Chemicals alone will not sort it out if the drainage isn't right the
moss will always win. Lawn sand (aka ammonium ferrous sulphate) is
almost as good as weed and feed unless you have nasty perennial weeds.

--
Regards,
Martin Brown