Moss Control in Lawns 

Mosses are plants that have a shallow root system and form a mass of fine stems wherever conditions are favorable. Mosses do not harm grass plants; they survive and can thrive in conditions where grass struggles. Therefore, when conditions are maximized for grass to thrive and minimized for moss to survive, the grass wins.

What are the reasons for moss succession? What can be done to address this issue?

  • Moss survives well in acidic soil (low pH), while grass has difficulty. The pH of your soil can easily and inexpensively be determined with a simple soil test. The ideal pH for grass is 6.5, so if yours is in the low range, you may have to apply as much as 2-3 bags of lime per 1,000 sq. ft. to make this adjustment. Remember that lime takes 3 years for a complete reaction, so don’t expect instant results. You are, however, addressing one of the most important and underlying reasons for moss succession. 

  • Poor drainage can be another factor. Aerating the soil and/or applying gypsum can help with soil compaction, but more severe conditions need addressing with tile drainage.

  • Too much shade is another concern. We often don’t notice how much trees grow through the years until we see moss creeping in, grass fading out, and sun-loving flowers no longer blooming. Pruning or eliminating shade producers might be in order.

  • Low soil fertility will starve grass and not affect moss at all. Feeding your lawn with an all-natural fertilizer that will slowly release nutrients to the grass plant and, very importantly, build healthy soil. This, in turn, will allow your lawn to thrive and out-compete moss.

  • Should I use a moss control product? Yes, you can use it as a tool, but such a product will likely just top-kill moss. If the aforementioned measures are not addressed, moss will likely return. Once you have progressed down your “moss journey”, a moss control product should take care of any residual rascals.

  • Make sure when re-seeding to use the correct grass seed mix for your site and conditions. If it is shady, make sure to include fine-leaf fescues or turf-type tall fescues in the mix.

  • Lastly, some folks enjoy moss as a no-maintenance ground cover. It’s very soft, very green, and very attractive in the eyes of some beholders… fairies love it...nevermind, we’re done!

Kate Ratta