Moss in lawn? Here’s why

Q. I noticed I have a lot of moss in my backyard. It looks like the moss is taking over the backyard from my grass. What can I do to stop this and get rid of the moss?

John from Canfield

A. Although it seems like a takeover this time of year, the moss is not pushing out the grass and taking over your backyard.

The moss is filling in the areas in your yard where the grass has stopped growing. Mosses, along with liverworts and hornworts, make up a group of primitive land plants collectively called nonvascular plants (specifically Bryophytes). These very old types of plants not only lack vascular systems of the more advanced plants we see every day, they also reproduce via spores instead of seeds.

When moss is found in yards it is an indication that conditions are not good for growing grass. When the grass stops growing and bare spots appear, the moss moves in. The problem can be solved by determining the underlying cause(s) for the decline of the grass.

One cause can be can too much shade. The need for sunlight varies by the type of grass but, in general if grass gets less than four hours of sun a day, the growth of the grass is greatly affected. To help grass in shaded areas, you can set your mower to mow at its highest level.

Another reason for limited grass growth could be compacted soil. Compacted soil can be alleviated by aeration. If the yard or area of the yard is wet, has poor drainage, your grass will not like having wet roots, and it will perish. But the moss will thrive. Finally the soil may be too acidic (low pH) or be poor in fertility. Mosses thrive in acidic soils where the fertility is low. Many homeowners try to remedy this by spreading lime on the soil. But how much lime is best? Don’t guess, soil test! To find out the fertility and pH of your lawn soil I recommend you have a soil test done.

Once conditions are favorable for the grass to grow, the grass will return and the moss will go away.

For more information about moss in lawns, visit http://go.osu.edu/mossylawn

For more information on nonvascular plants, visit http://go.osu.edu/nonvascular

Today’s answer is provided by David Sprague, OSU Extension master gardener volunteer. Call the office hotline at 330-533-5538 to submit your questions. Regular clinic hours are Mondays and Wednesdays from 9 a.m.-noon.