Posted: 03/02/2014 at 19:41
Hi Sara and welcome
You're right in that shade is probably making the moss much worse - we had a similar problem when we moved here as the lawn had been really neglected and apart from shade from the trees, the fallen leaves had been left on them for several winters.
Raking firmly with a lawn rake like this
to remove as much moss and thatch (dried grass at the soil surface) as you can, and spiking the lawn with a fork to increase drainage, and in the spring treat it with a lawn treatment like Evergreen Complete or similar which will kill the moss and weeds and fertilise the grass. Then another raking to remove the dead moss when it's died and turned black - it looks alarming but don't worry, the fertiliser will help the grass spread to cover the bare patches.
Regular mowing (not too short) at least once a week will help - don't put the first frew mowings in the compost bin after the lawn treatment as the weedkiller will contaminate your compost - bag it up and bin it or take it to the tip.
And while the raking is hard work, it's cheaper than a gym membership, and while you're far too young to have flabby upper arms, it's never too late to work on preventing them believe me