Every spring and summer, I receive a lot of phone calls at the Lee County Extension Office about moss taking over lawns. Usually, the caller is slightly frantic, worried that this low-growing green invader is actively murdering their turf.
Let me come clean right off the bat: If you have moss, it is completely okay. Moss is not killing your grass.
Mosses belong to an ancient group of non-vascular plants that have thrived on Earth for hundreds of millions of years. Because they don't have true roots or a vascular system, they cannot choke out, parasitize, or kill your turfgrass. Instead, they are simply opportunistic survivors. They are perfectly adapted to slip into areas where the soil is too shallow, too poor, too acidic, or too shady for anything else to grow.
Think of moss not as a lawn criminal, but as the canary in the coal mine for your yard. It is telling you exactly what is going on beneath the surface.
Moss growing in a shady turf area in West Lee County. Moss can worry some gardeners who think that the moss will kill their grass. This is not the case; and the most is usually filling a gap where grass cannot grow. Photo by Amanda Bratcher
Why is the Moss There?
If you have moss growing where you would prefer a lush turf, it means the current environmental conditions favor moss over grass. Some moss species love constant moisture, while others can tolerate long periods of drought interrupted by brief summer rains.
If grass is thinning out and moss is moving in, it is usually due to a combination of four things: deep shade, acidic soils, soil compaction and poor drainage. Grass needs more sunlight to generate enough energy to support its growth; moss can thrive without it. Compacted, heavy clay soils suffocate grass roots but give moss a perfect surface to cling to. Turf species struggle to take up nutrients in highly acidic soils, so they starve before they can even get going. Our preferred turf species also don't generally like areas that stay soggy or hold water, but these areas create a perfect habitat for moss.
How to Create Habitat for Your Turf (rather than moss)
If you are determined to establish turfgrass in a mossy area, you cannot simply scratch up the moss and throw down seed. If you don't change the underlying soil chemistry and environment, the moss will win.
To shift the scales back in favor of grass, follow this playbook:
Test, Don't Guess: Stop by your local NC Cooperative Extension Office and pick up a free soil testing box to send to the NCDA&CS state soil lab. Once your report comes back, we can see exactly how much lime you need to raise the soil pH and what fertilizer is required to fuel grass growth. Otherwise you are just guessing and you could possibly make it worse!
Add a Layer of Organic Matter: Spread about an inch of high-quality compost over the area. Organic matter is incredibly helpful for getting grass established. It builds a healthy habitat for beneficial soil microbes, holds onto vital moisture, and keeps the overall soil temperature cooler during our brutal summer heatwaves. Make sure you utilize compost and not topsoil! Good compost should not introduce weed seeds into your lawn areas, but topsoil can!
Let the Light In: Prune back lower tree limbs or thin out dense tree canopies to increase the amount of ambient sunlight reaching the ground.
Select a Shade-Tolerant Grass: No turfgrass thrives in total darkness, but some handle shade better than others. In our region, Zoysiagrass offers the best shade tolerance of the bunch. Just remember this is a warm-season grass and it goes dormant in the winter.
This moss is in its sporophyte phase. This is when it creates spores for sexual reproduction. The red structures are called archegonium, made up of a capsule and a seta. The spores will be released from these structures. The green carpet below is the gametophytic stage. Photo by Amanda Bratcher
The "Lazy Gardener" Alternative: Embrace the Moss!)
If you look at a deeply shaded, compacted area and realize you don't want to do all the heavy lifting required to amend the soil and cut down tree branches, there is a wonderfully low-maintenance alternative: Tolerate and embrace the moss.Fascinatingly, moss is notoriously difficult to establish intentionally. There are specialty gardening circles where homeowners spend hundreds of dollars buying moss slurries and trying to coax it to grow on purpose.If moss has volunteered itself on your property and is thriving completely for free, it is offering you a beautiful, vibrant green groundcover that never needs to be mowed, never needs to be fertilized, and stays green without your intervention. Sometimes, working with nature instead of against it is the best gardening decision you can make. It gives you more time to worry about your tomatoes!
Get in Touch!
Amanda Bratcher is the horticulture agent with N.C. Cooperative Extension—Lee County Center. If you are ready to tackle your mossy areas, stop by our office at 2420 Tramway Road in Sanford to grab your free soil testing kits! You can also reach us at 919-775-5624 with any questions, or visit our website to sign up for our upcoming seasonal gardening classes.
