Moss – lawn weed causes and treatments

Moss is a moisture loving plant and can quickly overtake a lawn and form its own ‘lawn carpet’ which can smother the grass and weaken the lawns vigour.

Causes of Moss on lawns

Moss is symptomatic of wet, poorly drained soils. Grass can also be quickly invaded by moss where areas of lawn are shaded.

Another cause of moss on lawns is when the lawn mower blades are set to low and the grass is scalped. If the grass is cut too short it loses its vigour and its growth is severely inhibited. In these conditions moss will quickly take advantage and establish itself in the lawn.

How to get rid of moss.

Many lawn treatments such as weed and feed contain ‘moss killer’ that contains chemicals that will selectively kill moss off. Once the moss is dead it can be raked out of lawn and disposed of. Care must be taken when using a moss killer as when the dead moss is removed it can leave large bare patches of lawn that are prone to infestation from other weeds. These bare areas should be quickly attended to by seeding or returfing.

Although moss killers may temporarily rid your lawn of moss, the moss will continue to recolonise the lawn until the underlying causes of the conditions that suit moss are identified and rectified.

To treat these underlying causes we must employ lawn care methods that will also benefit our lawn in many other ways as well as prevention of moss infestation. Moss will find it harder to establish where the grass is thick and strong. These lawn care techniques include

  • Aerating the lawn to help reduce soil compaction, improve soil drainage and improve grass root development
  • Identify drainage problems and if necessary install appropriate drainage channels
  • Identify trees and other objects that cause areas of the lawn to be shaded and either move / remove them to a more suitable area or rethink the design of the lawn.
  • Mow the lawn at the correct height so that it retains a strong vigour.
  • Prevent that build up and remove existing layers of thatch using a scarifier.

If you rectify the problems of soil drainage compaction and shade then there should not be any need for moss killer as the moss will not survive in the revised conditions. Hopefully by looking at treatment of lawn moss you can see many lawn care techniques have an impact on a number of lawn quality factors and that like most lawn problems, prevention is better than the cure.