MOSS IN LAWNS

From the Penn State Extension office, Franklin County

          Do you have moss growing in your lawn?  While it is green like the grass, some people want to get rid of it.  If you have this problem here are some suggestions on why you have moss and what to do to get rid of it.

Moss is a simple plant that does not compete well with the grass.  It is in your lawn because your grass was weak and thin.  Moss spreads by spores not seeds, so the spore needs to land on a bare spot to germinate.  There are many reasons that a lawn will thin out.  We know that shade can do it often it is because the tree that was planted years ago has gotten larger and the grass that use to grow in full sun when the tree was first planted, is now growing in dense shade and grows slowly and some plants die.  This leaves bare spots that moss can grow in.  Poor drainage, soil compaction from foot traffic, poor soil fertility and low soil pH all can cause grass to grow poorly.

If the cause of poor grass growth is not corrected, then just sit back and enjoy the moss.  But if you want to get rid of it you need to correct the problem.  Do a soil test and if your pH is low, then add lime.  If the nutrients necessary to grow good grass are low, then you need to fertilize.  If your lawn is all bluegrass we know that does not grow well in shade, so you need to introduce shade tolerant species this fall.   You can dethatch next fall to remove the moss and then overseed the area to get your shade tolerant grass started.  If you also need to use some chemical material to control the moss, there are products available that will control moss.  Most use iron, copper or zinc as the active ingredient to control the moss.  However if you just use the chemicals and you don’t correct the problem with your lawn, the moss will quickly grow right back in the area.