Asked April 27, 2017, 2:18 PM EDT
How can I get rid of moss spores growing in my flower gardens and lawn. The areas keep getting bigger and bigger! I'd prefer an organic solution since I grow organically.
Ramsey County Minnesota
Thank you for the question. Moss thrives where there is shade, low soil fertility, compacted soil, dampness and low pH, usually in a combination of two or more of these. It is important to know that even if you remove the moss organically by aggressive raking it will return if the underlying conditions are not treated. There are chemical products that you might find acceptable to use such as iron sulfate, copper sulfate, fatty-acid soaps, and potassium salts. Some of these can harm desirable plants so don't apply at rates higher than specified on the label. Generally, you need to change the conditions to allow for more sunlight and less moisture. If applicable, it may be necessary to prune overgrown shade trees and shrubs to let in the light.
Here is a publication from Oregon State Extension outlining moss control: http://extension.oregonstate.edu/gardening/how-get-rid-moss-your-lawn
A soil test might be helpful. It will tell you if your pH is low and if more organic material like compost needs to be added to your soil. Here is a link with information on submitting a soil sample for testing: http://soiltest.cfans.umn.edu/
Thank you for contacting Extension.