Moss is a tiny non-flowering plant that is one of the most troublesome weeds in the lawn. One basic rule of trying to control moss is that is a symptom of poorly maintained grass, not the primary cause. So killing the moss will help to alleviate the problem in the short term but to ensure permanent freedom the cause or causes must be correct.
Dampness is usually the prime suspect in the spread of moss, so spring and autumn are the main periods of rapid colonisation. This is brought about by poor drainage and or compaction.
Moisture is not the only cause as moss can also be a common sight on sandy soils which are free-draining. This can be caused by underfeeding the lawn, over acidicty, too much shade or even cutting the grass too close.
Control
Applying a moss killer in spring and autumn, either by adding lawn sand or by chemical moss killer. Lawn sand in spring will burn the moss, providing a boost to grass growth. A chemical moss killer, such as Phostrogen Moss Killer & Lawn Tonic Soluble can be used in spring and autumn and is watered in to the affected area and then after a couple of weeks the dead moss is raked up and any bare patches reseeded
Feeding the lawn each spring will encourage the healthy, strong grass to grow
Don’t cut the grass too short as it can weaken it, allowing moss to quickly spread. Also grass that is too long, especially in damp weather will encourage trailing moss to grow
Reduce shade on the lawn, if possible. Moss normally occurs under trees so remove lower branches of the tree to allow light on to the grass
Scarifying and aerating the lawn in autumn, and if needed lightly in spring, will improve the drainage. This is one of the most important operations in the control of moss
After scarifying and aerating, top-dress the lawn, brushing it lightly into the soil. Top-dressing will help build up the fertility of the soil, improve the drainage and keep moss at bay
