Why make room for moss and lichen?

Mosses and lichens are the quiet architects of a woodland garden. They soften stone, blur the edges of paths and turn a bare log into a miniature landscape, all without needing feeding, staking or deadheading. They are also ancient — mosses have been on the planet for hundreds of millions of years, and lichens are not plants at all but partnerships between fungi and algae, quietly photosynthesising on bare rock and bark where nothing else can manage.

For wildlife, they are far more useful than they look. Damp moss holds moisture and shelter for springtails, mites, tiny spiders and the larvae of insects that feed the birds. Lichens are grazed by snails and some moths, and birds such as long-tailed tits weave lichen fragments into their nests. If you have a shaded corner, a stone wall or an old tree stump, you already have the beginnings of a habitat.

What moss and lichen actually need

Get these four things right and the rest tends to follow:

• Damp, humid air. Shade from a wall, fence or tree canopy helps enormously. A north-facing border or the north side of a shed is ideal.
• Clean air. Many lichens are sensitive to sulphur dioxide and other pollutants, which is why shrubby, beard-like lichens are a genuine sign of good air quality. If your area is polluted, mosses and crusty lichens will still do well.
• Stable, undisturbed surfaces. Moss likes slightly rough, porous, lime-free surfaces: sandstone, brick, old timber, bark, slate, terracotta. Lichens need a surface that is left alone for years.
• Consistency. A damp spring, a shaded summer and a mild winter suit them. They dislike alternating bone-dry and soaked conditions, and they dislike being scrubbed, moved or fed.

Start with the surfaces you already have

Before you buy anything, look at what is already growing. Cushiony mounds of grey-green moss on a step, silvery patches on a roof tile, orange Xanthoria on a wall — these are your local species and they will spread fastest because they are already suited to your conditions.

Places worth leaving alone: the base of a mature tree, a stone retaining wall, the gaps between patio slabs on the shaded side of the house, an old wooden bench, a dry stone wall, gravel or gravel-boarded paths, rotting logs, tree stumps, and the shady strip along a fence. Avoid putting weed membrane under these areas; it starves the surface and stops moss establishing.

Giving moss a helping hand

If you want to speed things along, transplanting moss is straightforward. Take a generous handful from a surface similar to the one you are seeding — a lawn, a wall, a path — and whisk it in a blender with a pint of water and a good glug of milk or buttermilk until it becomes a thin, green paste. Paint or pour this over damp, bare stone, brick or timber in shade, then keep it misted for the next few weeks. Early autumn and early spring are the best times, when the weather is damp and growth is ticking along.

Watering with rainwater from a butt is far better than tap water, particularly in hard water areas where the mineral content works against moss. A gentle mist in dry spells, a little leaf litter allowed to settle in corners, and a mulch of bark chippings around nearby plants will all help hold humidity. On lawns, simply raise the mower height and cut less often — moss will move in of its own accord.

Encouraging lichens — the slowest reward

Lichens cannot be transplanted in the way moss can. They arrive when conditions suit, usually as tiny fragments or spores drifting in on the wind. What you can do is offer them somewhere to land and then leave it be. Rough, weathered timber, unpointed stone walls, slate roofs, old fence posts and the bark of mature oaks, ash and willows are all excellent. Fruit trees are especially good: lichen-rich branches are a sign of an old, well-managed orchard.

Patience is the price. Crusty lichens may take five years to become noticeable, and the leafy, shrubby kinds can take decades. Avoid cleaning stonework or timber in shaded corners, and resist the urge to "tidy" the very surfaces that are quietly colonising.

What to avoid, and keeping paths safe

A few common gardening habits undo years of slow growth in an afternoon:

• Pressure washing. It strips stone, mortar and moss in one pass, and lichens rarely return to the same surface.
• Patio and path cleaners. Chemical moss killers, often based on ferrous sulphate, will kill far more than the target area.
• Regular raking and scarifying. Fine for a bowling-green lawn, ruinous for moss carpets.
• Rich feeding. High-nitrogen fertiliser and heavy mulching encourage lush grass and weeds at the expense of moss.
• Moving logs and stones. Each time you shift a log you disturb beetle larvae, fungi and the moss that has taken years to establish.

Do keep one practical eye on safety. Moss on a sloping path, step or decking can be genuinely slippery in wet weather. Brush it lightly with a stiff broom or lift it with a hoe from the main walking route, scatter a little grit or sand in frosty spells, and leave the damp, out-of-the-way corners to grow on undisturbed. That way you get the texture, the colour and the wildlife, with a dry route to the back door.