If you are looking for an alternative to conventional turf, consider a moss lawn. Moss has been an integral element of Japanese garden design for centuries. Meanwhile, in the rest of the world, the Zen-like look of moss gardening is uncommon. This is a pity because a lush moss green carpet can grow just about anywhere except in arid environments. It can also thrive as a groundcover in many places where turfgrass is difficult to establish, such as steep hillsides.
The drawback of a moss lawn is that live mosses for landscaping are not as readily available as grass seed, and a moss lawn is more expensive to install than a lawn. However, the initial investment pays off because once a moss lawn is established, it requires much less upkeep and maintenance. All things considered, a moss lawn is more sustainable than turfgrass.
Before choosing, it's important to weigh the pros and cons of moss lawns when compared to turfgrass lawns. Find out whether a moss lawn is right for you, and what’s involved in growing and caring for it.
What Is a Moss Lawn?
A moss lawn is a dense stand of moss, a low-growing plant. Mosses don’t have a vascular system of roots, as do other plants; they absorb water and nutrients through their leaves. They grow slowly and are propagated through the production of spores, not by seeds.
Contrary to popular belief, you can step on a moss lawn. Most mosses withstand light foot traffic. Right after the moss lawn is installed, it is actually recommended to walk or sit on it to help the moss attach to the soil. For heavy foot traffic across a moss lawn, on the other hand, it is better to add a walkway or lay down stepping stones.
Walking on a moss lawn feels different from walking on a grass lawn. While moss is soft, the surface feels slightly uneven and spongy, unlike a mowed lawn where all the grass blades are cut to the same height.
The Benefits of a Moss Lawn
Once established, a moss lawn has several advantages over turfgrass, most of which fall into the low-maintenance category.
As moss is short, under 4 inches, it does not require mowing. This not only saves you time, it is also more sustainable—no use of fossil fuel, and no air and noise pollution from a lawn mower.
Moss can grow in poor soil, which makes fertilizer unnecessary to keep your moss lawn healthy. It is also unbothered by pests so you can also cut out the pesticides. Wildlife generally leaves mosses alone.
Moss also does well in difficult conditions such as compacted or rocky soil, or slopes and steep hillsides where turf would be easily washed out by erosion. In fact, moss is often the planting of choice for erosion control.
A moss lawn is lush green when the leaves, which absorb water and nutrients, are well-hydrated. But that does not mean that mosses have high water needs. Once mosses are established, their water needs are actually low. Mosses don’t need irrigation to survive, even in arid conditions. In periods of dryness, they turn dry and go dormant. And when there is a sudden heavy downpour, they soak up all the water they can.
Disadvantages of a Moss Lawn
While there are many mistaken assumptions about the drawbacks of moss lawns, it's indisputable that this plant has some disadvantages over turfgrass when used as lawn ground cover.
Most moss species prefer relatively shady conditions, and if you have a sunny lawn, it may be difficult to find a moss suitable for your region that performs well on a lawn that receives direct sun for most of the day.
Moss, while not as tender as most people think, is by no means as durable as a turfgrass lawn—especially a grass lawn planted with species aimed at holding up under heavy foot traffic, A moss lawn may not be practical for lawns that must serve active families that enjoy outdoor games, or one that has dogs that spend a lot of time in the yard.
Moss lawns grow best in acidic soil, where the pH is 6.0 or lower. If you live in an area with alkaline soil, growing moss may be difficult or impossible unless you first perform extensive soil amendment with a material that lowers the soil pH.
Moss lawns need to be kept relatively clean of fallen leaves and other debris. This is rather easily done simply by making a pass over it with a bagging lawnmower, but it does add extra maintenance steps. Then again, moss does not need to be mowed in the traditional fashion, so this characteristic really doesn't cause a moss lawn to be more labor-intensive.
Moss is normally planted from flats of live moss, and this is not always readily available—and certainly less common than seed or sod for turfgrass. You will likely need to order moss in trays of living plants from online retailers, and the cost of a moss lawn is almost always considerably more than that of a turfgrass lawn.
Find the Right Site for a Moss Lawn
Moss lawns are more expensive than sowing grass seed or laying sod for a lawn. To make sure your investment will last, it is crucial to select the right site for a moss lawn.
The first step is to identify the microclimates in your yard. What is the sun exposure in the different areas? Are there deciduous trees or evergreens that cast shade, how densely, and at what time of the year? Does your yard have any moist, shady spots? Also pay attention to wind exposure, as wind can dry out the soil.
Growing mosses is not difficult but if you’ve never grown mosses, a gradual approach might be the wisest. Start with a corner of your yard, select moss species that are suitable for its sun exposure, and see how they do for a season or so before trying to grow a full-scale moss lawn.
How to Choose Mosses
As with all other plants, sun exposure is crucial when selecting the right moss for a location. Mosses are commonly associated with growing in shady locations but there are also species that grow in sun or partial sun.
The other important consideration when selecting a moss is the growth habit. Bryum caespiticium, also known as sidewalk moss, for example, is a sun-tolerant moss but it grows in clumps so it is less suitable for a lawn with a carpet-like, even surface.
Here are a few select mosses for lawns in different light conditions:
- Atrichum angustatum (star moss, slender starburst moss, lesser smoothcap moss): Compact, low-growing moss that can grow in the shade but prefers sun or partial shade/partial sun.
- Atrichum undulatum (big star moss, Catherine’s moss, crane’s bill moss, crown moss, starburst moss): Prefers shade but can grow in partial shade/partial sun; needs moist soil and shrivels up when dry.
- Climacium americanum (tree moss): Grows in deep shade as well as partial sun, ideal for waterlogged areas or storm water run-off. One of the taller mosses, growing 4 to 5 inches tall.
- Dicranum scoparium (mood moss, windswept moss, broom moss, footstool moss, rock cap moss): Dense, soft, brilliant green moss that grows in shade and partial shade and can tolerate drier areas. It prefers acidic soil.
- Hypnum imponens (sheet moss, feather moss): Low-growing moss that does best in shade but can also grow in partial sun. It can withstand light to medium foot traffic.
- Leucobryum albidum (pincushion moss): A versatile moss that grows in shade, sun, and partial shade/partial sun, and in a wide range of temperature and soil conditions.
- Leucobryum glaucum (cushion moss, white moss): Moss with a round cushion shape that does well in shade and can tolerate morning sun. It prefers sandy soil. Its light blue/green color gets a silvery-white cast when dry.
- Polytrichum commune (haircap moss, awned haircap moss, blue moss, blue hairy cap): A versatile moss that grows in shade, sun, and partial shade/partial sun. Good for erosion control on slopes.
- Thuidium delicatulum (fern moss): Moss with fronds that grows in shade and partial shade and prefers wetter locations. Good for erosion control on slopes.
How to Plant and Grow a Moss Lawn
Follow these steps to grow a moss lawn:
1. Check the Soil Acidity
Most mosses prefer acidic soil between a pH of 5.0 and 5.5. To make sure the soil pH is within that level, do a soil pH test of the intended planting area. Especially if you are turning a turfgrass lawn into a moss lawn where you have added lime to the soil in the past to increase the soil pH. Chances are that the soil pH is too alkaline for moss. In that case, you need to slightly acidify the soil by adding compost, manure, or another soil acidifier.
2. Prepare the Soil
After checking and adjusting the pH, clear the area of any weeds, plant residue, and other debris. Turn over the soil, then level and rake it. The surface should be firm but still have some texture, which helps the moss make good contact with the soil.
Water the planting area well to the point where it’s soaked but avoid puddles of standing water.
Depending on the state that the moss is in when you receive it, you might need to soak it in a bucket of water or kid’s pool until is it rehydrated. If the moss is green and looks alive, there is no need to soak it.
Moss has no roots so it is not planted in the soil but just placed on top. Press the moss into the soil and secure it with landscaping pins. Light, slow, flat-footed walking on newly laid moss from time to time can also help it establish but make sure that you do not dislodge the patches when stepping on them.
Water the planting area thoroughly and keep it constantly moist for the first four to six weeks until the moss is established—when it won’t detach from the soil when you try to gently lift it.
Detailed instructions on how to plant moss can also be found here.
Care and Maintenance
After moss is established, it will not need regular watering. Even in periods of no precipitation, moss absorbs moisture from the air. In extended periods of dry weather, if the moss starts to look excessively dry, you can rehydrate it with a sprinkler or a mister for a few minutes a couple of times per day until you see the moss change to a more vibrant color.
Especially in the early stages before the moss forms a dense carpet, weeds are likely to grow in your moss lawn. Pull any weeds gently by hand as soon as they emerge. If you let weeds take hold and they get too large or numerous, removing them can damage the moss carpet. Moss does not respond well to herbicides so manual weeding is the way to go.
The only other maintenance required for a moss lawn is to remove any leaves in the fall that can mold and rot and deprive the moss of light.
Moss lawn does not require fertilization. Changes in the moss color are seasonal or due to moisture levels and are perfectly normal. Unlike in grass and other vascular plants, color changes are not a sign of nutrient deficiency.
The Benefits and Ecology of a Moss Lawn. Clackamas Soil and Water Conservation District.