Meeting moss on its own turf

Few gardeners would turn down an invitation to curl up on a carpet of luminescent moss or refuse an opportunity to run their fingers over a miniature forest of soldierlike spores on a moss-covered log. Few would fail to admire the smooth, verdant covering on a mossy rock. Gardeners with a gentle touch have probably lifted a tuft of moss from an obscure place to a prominent spot and encouraged its growth where they could enjoy the beauty and green mystery. And with the fall turf season ahead, that’s the approach that turf-keepers who struggle with too much moss and not enough turf may want to consider.

It’s no secret that moss is the turf-keeper’s burden. Just ask those whose thrill is an expanse of thick, single-species grass but who spend countless hours (and dollars) trying to eliminate moss from the lawn. The struggle will continue until people understand that moss is present because it likes certain conditions, and the turf isn’t thriving because it doesn’t like those conditions.

Moss generally likes high moisture, shade, few nutrients and an exposed surface on which to grow. The soil in our area is acidic and often compacted by poor drainage — just what lawn mosses love and cool-season grasses hate. So I encourage keepers of the turf to give up the fight and let the mosses to have their way. If that doesn’t sound appealing, consider what it will take to grow a strong turf: cutting trees to create more sun exposure, and tilling the soil and adding amendments to improve drainage and soil fertility.

Depending on the design and how the landscape is used, turf — in moderation — may have its place. But once you’ve seen a moss lawn, walked down a mossy path or reclined on a mossy cushion, you might decide you’re better off working with the invading moss rather than being a slave to the blades of the grass and the mower.

Establishing a moss lawn can take some work, but if you’re already waging a moss/turf war you’re off to a great start. It’s just a matter of pulling out the grass by hand and removing leaves and other debris via light raking or leaf-blowing. Bare spots can be filled in with carefully transplanted nearby mosses — or just cover those areas with compost and let the mosses find their own way in. I have a small lawn area, rather like a mossy meadow, that I mow once or twice a year. With just the right amount of shade and moisture, the plot holds red fescue, moss and a beautiful smattering of small bulbs and wild flowering plants, including blue-eyed grass, hawkweed, clover and violets.

If you start from scratch, there are several methods to consider. I call one the “prepare the soil and the moss will come” method. This involves exposing, testing and adjusting the soil for a pH of 5.5 (typical of the acidic soils here) and waiting for spores to blow in from nearby locations. Depending on whether the spot is sunny or shady, mosses that prefer that particular site condition will soon settle in, and you’ll have a full covering in two to five years. In the first year, the moss will need watering and maintenance (removing leaves, twigs, seeds and bark and weeding grasses and other plants; these will become annual tasks).

Some people recommend starting a moss lawn with dried, crumbled fragments. But this approach seems generally less successful, because few kinds of moss naturally propagate this way. More commonly, they come from spores, and even fewer of those form carpets. If you want to use this method, read up on which moss types are best to work with.

Another technique is “immediate installation,” which is not advised for large-scale installations (more than 75 square feet) and is discouraged unless you have access to a legal source. As with wild plants, you must have permission from the landowner (whether private or public) to collect mosses. There is considerable concern about overharvesting of log moss for the floral industry. Moss grows slowly, and removing it alters the site for a long time. Furthermore, transplanting moss from another site can be risky; it can dry out in the process, and in any case it might not be compatible with your site and soil conditions.

If you’re considering converting from turf to moss, read George Schenk’s Moss Gardening, a thorough text that’s not too technical. Hopefully, the first paragraph will capture your imagination and lead you outside to explore and make friends with the mosses around you.

Another resource is your own observation. Take a walk in the woods or through an open area — even around town — and note the various mosses and their preferred habitats, from sunny/dry and sunny/damp to shady/damp. Note their many colors and textures and where they grow best. Approach moss with respect, patience and new eyes, as you would a person or plant you know little about. Get to know mosses, and work with them rather than against them. Start on a small scale, and if it doesn’t work, choose another spot or another type of moss. The mosses will certainly guide you and let you know how you’re doing.

[Alison Arnold is director of horticulture at The North Carolina Arboretum. She can be reached at 652-2492.]