People often ask whether moss can be grown from spores the way you sow seed. It can, in principle, but it is slow and unpredictable, and there is almost always a faster route to the same place.
How moss spreads naturally
A ripe capsule, the little stalked pod that stands above the leafy moss, is the spore-bearing generation, and when it dries and opens it releases spores as fine as dust to the wind. A spore that happens to land somewhere damp and shaded germinates into a fine green thread called a protonema, which creeps over the surface and then buds into the recognisable leafy shoots. The whole sequence is gradual and depends entirely on the surface staying damp throughout. None of it involves roots, either: the leafy moss anchors itself with thread-like rhizoids and takes its water in over its whole surface, so there is no seedling drawing on a store of food the way a sprouting seed does.
The realistic methods
In practice, gardeners propagate moss from fragments rather than spores, because almost any small piece of moss can regenerate a whole new plant, a knack that makes it one of the easiest things in the garden to multiply. The two reliable approaches are pressing fresh patches onto prepared ground, and the slurry method, blending moss with water or buttermilk and spreading it. Both are described in the growing guide, and both are far quicker than starting from spores.
If you really want to start from spores
Scatter the contents of ripe capsules, or lay whole capsules, onto a firm, damp, low-nutrient surface in shade, and keep it constantly moist and undisturbed for weeks to months. Results are erratic; whatever moss spores happen to be drifting in your air may colonise the patch before your chosen species does. A firm, slightly acidic surface such as fired clay, unglazed terracotta or a clean paver tends to work better than loose soil, which shifts and dries. Treat the whole thing as an experiment rather than a reliable way to cover ground.
The protonema, and why patience is everything
It helps to know what is going on during the long wait. A germinating spore does not turn straight into a recognisable moss; first it grows a sprawling mat of fine green threads, the protonema, which can look like little more than a green algal film for weeks before the upright leafy shoots, the part you would call moss, finally bud from it. Many people give up at the film stage, assuming nothing is happening or that algae have taken over. The threads are fragile and depend utterly on the surface never drying, so the slightest neglect sets the whole thing back. This is the real reason spores are a poor way to cover ground: the vulnerable phase is long.
Where growing from spores does make sense
For covering an area, fragments win every time. But sowing spores has its place. It is how laboratories and serious enthusiasts raise particular species that are hard to source as living material, and it is a genuinely rewarding thing to watch under controlled, near-sterile conditions on agar or a sterilised substrate, where competing spores from the air are shut out. Approached as a patient experiment rather than a quick way to green a path, it is a window into a part of the plant's life most people never see.