Extensive Moss

Asked May 5, 2017, 3:13 PM EDT

My backyard faces south and has many mature oak, pine and cherry trees. When I first established the yard 30 years ago, I added black dirt (I believe it came from a boggy area) to the yard and mixed / tilled it with the sandy soil to a depth of from 6 - 12". The yard was established via seed. For the first several years, the grass was healthy and full but then the yard got a mold and it has never been healthy since. Moss became established and I have tried to rake it out, add lime and fertilizer to no avail.. I have had a service try to re-establish the lawn but that failed. Last year, I had several soil samples done at the U of M but the results did not indicate a need for additional nutrients and the pH was near normal (I do not have the results handy - not sure where I put then). I have cleared some of the trees and raised the canopy and I am getting more sun. This year I'm thinking or re-establishing the lawn and adding / mixing Cowsmo compost to the soil. I am hoping that you may have a suggestion on how this should be done. My thought was to kill the grass and moss with roundup, wait a while, till in the Cowsmo, re-seed and hope for the best but I need some direction - maybe I'm being too drastic. Any help will be appreciated.

Added 5/6 - I have tried residential moss killers - I believe one of them was a Bayer product. It was a liquid product spayed on with a hose. I've also tried a granular product which was even less effective. In both cases, they had a minor impact (more impact with Bayer) but the moss never disappeared and came back ever worse.

Anoka County Minnesota lawns and turf moss in lawn

1 Response

Moss thrives in moist, shady areas and/or compacted soil. I am guessing that area is damp and was shaded. Letting the sun in will help immensely. The moss can be ranked out. Then you may wish to aerate that area also and then seed. As long as your soil test indicated the soil was neutral there is no need to add lime or any other additive except fertilizer. Here is a link to our article on moss. Maybe you can pick up a few other hints. Good luck. http://www3.extension.umn.edu/county/benton/county-horticulture-educator/article/moss-lawns