Are you unintentionally growing a moss garden on your roof? Moss can be quite a nuisance and typically grows on north facing roofs. A moss-covered roof is very unsightly and can even cause gaps in your roof tiles or slats as it grows, which could possibly lead to leaks. It is best not to allow moss to remain.
One way to clear the moss from your roof, is to treat your roof with roof cleaner (on a cloudy day so it does not evaporate) to kill the moss and help stop it from growing back. When choosing a cleaner ensure to get one that is environmentally safe as the run-off could find its way into flowerbeds or lawns below and kill your plants or grass. It usually takes 20 minutes for the roof cleaner to seep into the moss, then you can remove the moss with a stiff brush, possibly even a brush with an extendable pole.
You can also use plastic sheeting to protect nearby plants whilst applying the moss killer and hose down any small trees, plants and shrubs with water, after the cleaning, to dilute any spray or spillage that could have landed on nearby plants.