Moss can accumulate to high levels in most lawns but grows particularly well in poorly draining and shaded areas. While moss on its own won’t kill your lawn, it does fill in the gaps where the turf is not strong and will prevent the turf from growing. It is also an indicator that you may have other problems, such as low fertility, low pH, poor drainage, excessive watering, or compacted soil.
Ferrous sulphate (iron) solution is applied to the lawn in late winter/early spring. The iron draws moisture out from the moss and causes it to dry up, turn black, and die. The lawn benefits from the added iron and gives it a flush of early season greening. We strongly recommend applying moss control treatment in conjunction with power raking, as just treating the moss and leaving it in place does not allow the lawn to fill back in enough to outcompete the moss in the future.