Moss in our lawn

Asked September 5, 2018, 5:30 PM EDT

This summer we noticed large patches of our lawn that appeared to be dying out. On closer inspection, we discovered moss growing in patches. We could pull up the moss and there was bare ground underneath. What is confusing is that the moss patches are in areas of the lawn that get full sunlight. We have not watered this year because rainfall (with the exception of August) was plentiful. Any suggestions for what might be wrong? Someone suggested we might need to amend our soil. The thought of having to completely amend the soil in our entire lawn in daunting. Any assistance you can give would be greatly appreciated.

Hennepin County Minnesota

2 Responses

Some moss will grow in sunny areas. In this case, the moss is indicative of poor turf health likely due to compacted soil, poor drainage, and low fertility. Moss can also indicate low soil pH (acidic), but in Hennepin County this is not as likely due to our limestone bedrock. A soil test will help you determine your soil pH. Moss can also indicate thatch issues, but this isn't usually likely.

Here are some steps you can take to alleviate the issues with moss and improve your lawn's overall health:

Aerification: Fall is a great time for core aerating your lawn. This relieves compacted soil by removing soil cores and increasing the air (pores) in your soil. This will also help improve drainage. The soil cores left behind may look odd, but they will quickly breakdown back into your lawn. You can rent an aerator or hire a lawncare professional to do this.

Overseed: Choose a high quality grass seed appropriate to you site conditions (full sun, shade, etc.). Broadcast it up until mid-Sept. or wait until November and do dormant seeding.

Take a soil test now. Spring is id often a very busy time for the UMN Soil Test Lab, so I recommend you do a soil test now, so you'll be prepared for spring.

Apply a fall weed-and-feed to your lawn. This will help reduce competing broadleaf weeds and strengthen your grass plants as they go into winter.

Also - here is our Extension webpage on lawn care. Note the lawn care calendar, and the page on fertilizing lawns. The link to the dormant seeding page is also here.