Every garden has the spot where grass gives up: the dry shade under a tree, the damp north-facing bank, the corner that never sees sun. Fighting to grow a lawn there is a losing battle. Moss is the plant that actually wants those conditions, and used as ground cover it turns the garden's problem corners into its quietest, greenest ones.
Where moss earns its place
Moss comes into its own exactly where conventional ground cover struggles: deep or dappled shade, consistent moisture, poor or compacted soil, and acidic ground. In those conditions it gives you a soft, even, evergreen surface that needs no mowing, no feeding and almost no water once established, and stays green through winter and drought when grass has gone brown and patchy. It is lower input and lower effort, not a compromise.
Under trees
The dry, root-filled, shaded ground beneath a tree is the textbook place grass fails and moss flourishes. Moss has no roots to compete with the tree, takes nothing from the soil, and copes with the shade, so it carpets the ground where nothing else will hold. Clear the failing grass and weeds, firm the surface, and establish moss as below; the result frames the tree far better than thin, struggling turf.
Banks and slopes
On a shaded bank, moss does a practical job as well as a decorative one: a knitted moss carpet holds the surface together, slows run-off and reduces the erosion that bare or sparsely grassed slopes suffer in heavy rain. Choose creeping, carpet-forming pleurocarpous mosses for this, since they knit fastest into a continuous, soil-binding mat, as explained in acrocarpous and pleurocarpous mosses.
Among ferns, hostas and stone
Moss is the perfect understorey for the classic shade-garden plants. It sets off the bold leaves of hostas, the fronds of ferns and the foliage of woodland perennials, filling the ground between them with calm green instead of bare soil or bark mulch. Run it up to and between stepping stones and around the base of rocks and it ties a shady planting together into something that looks settled and whole. The Japanese tradition leans on exactly this; see Japanese moss gardens.
Establishing a large area
For anything bigger than a patch, the slurry method is the practical way in: blend moss with rainwater or buttermilk and spread or paint it over the prepared ground, or for the largest areas spray it, as in spraying moss slurry at scale. Prepare the ground first by clearing competition and firming the surface, keep it misted daily for the first few weeks while it grips, and accept that full, seamless cover takes a season or two to develop.
Keeping it
Upkeep is mostly a matter of leaves. The one thing that smothers a moss carpet is a thick layer of autumn leaf fall left to sit and rot, so sweep or gently blow leaves off through autumn. Beyond that, keep foot traffic light on young moss, top up moisture in long dry spells until it is well established, and otherwise leave it alone to thicken year on year. See the growing guide for the establishing detail.