Kusamono are the small plantings of grasses, wildflowers and herbs grown and displayed in their own right, often alongside bonsai to set a season and a mood. Moss is their usual finishing ground, the green skin that ties the planting to its pot and makes it look settled and complete.
What kusamono are
The word means "grass thing", and that captures the spirit: humble, seasonal plants rather than grand specimens, arranged to evoke a particular time of year or kind of place, a damp meadow, an autumn bank, a patch of spring woodland. Shown beside a bonsai they provide context and contrast; shown alone they are a quiet art of their own. The closely related accent plantings used specifically to complement a bonsai in a formal display are sometimes called shitakusa, and the line between the two is more about how they are shown than what is in the pot.
The place of moss
Moss does for a kusamono what it does for a bonsai: it covers the soil, keeps it cool and damp, stops it washing out in watering, and finishes the composition with a natural, aged look. Beyond the practical, it belongs to the aesthetic, standing in for the mossy ground these little plants would grow on in the wild and settling the eye. A fine, flat carpet moss over the surface, with the chosen plants rising from it, is the typical treatment, though a low cushion or two can suggest a bank or a tussock if the planting calls for it.
Setting a season
What lifts a kusamono above a pot of odds and ends is the reading of a season. A planting of spring ephemerals says something quite different from one of autumn grasses gone to seed, and the maker chooses material, pot and moss to point at a single moment and place. Traditionally a kusamono shown with a bonsai is picked to echo it rather than compete, matching the same time of year, so that tree, scroll and grass planting together suggest one scene. Grown for its own sake, the little planting simply carries the season on its own, which is why makers keep several going and bring each forward as its moment comes.
Plants and pots
Choose modest, seasonal material: ferns, sedges, grasses, small wildflowers, miniature hostas, anything that reads as a scrap of wild ground rather than a showy garden plant. The pot matters as much as the planting, usually a small, understated, often handmade ceramic or a simple slab, chosen to suit the plant and the season rather than to dominate. Restraint is the whole point, and an overworked pot or a flashy flower undoes it at once.
Making and caring for one
A kusamono is put together much as any small pot planting, with a bias towards a light, free-draining mix that suits the plant. Settle a division or a scrap of meadow into the pot or onto the slab, firm it, and dress the surface with a fine carpet moss pressed down so it beds into the soil, then water it in and keep it shaded and damp while the moss knits on. Because these are small, shallow plantings they dry quickly and want regular watering with rainwater and a position out of harsh sun, much like the moss that dresses them. Many are treated as seasonal, brought to their best for a display and rested afterwards. Clear debris, divide or replant as the material grows, and a kusamono can be kept and refined for years. The moss side of it follows the same principles as moss for bonsai.