Selaginella uncinata aka Peacock Moss

Selaginella uncinata is a low perennial in the Selaginellaceae family. Its native range spans central and southern China to northern Indochina. Gardeners call it peacock moss, blue spike moss, or rainbow fern. Its fine foliage looks like a fern or moss. The blue-green leaves give this plant its main garden value. It grows as a groundcover rather than an upright plant.

Creeping stems spread across the soil and root as they grow. They form a dense mat or trail over container edges. Garden plants reach about 0.25–0.5 feet (0.08–0.15 metres) tall. The RHS gives a lower maximum of 0.33 feet (0.1 metres). Spread reaches about 1–1.6 feet (0.3–0.5 metres). Growth is fast, though full size may take two to five years. The fine leaves have smooth edges and lack hairs. Their blue-green sheen can look stronger in low light. The RHS describes the foliage as partly evergreen.

This plant has no flowers, despite one source listing green blooms. Growers prize its leaves rather than a floral display. The RHS lists spores as one means of propagation. Division and stem cuttings also provide ways to make new plants. Rooted stems make division easy. The stems have no scent. Routine pruning is not needed. Remove dead or faded growth when it appears.

Choose a sheltered site with partial or deep shade. Direct sun can burn the foliage. Keep the soil moist and rich in humus. Loam and clay suit it, with acid to neutral soil preferred. High humidity also supports growth. Under glass, use peat-free, loam-based compost with added leaf mould. Water freely and feed each month from April through September. Hardiness guidance differs sharply between sources. American sources list USDA zones 6–10, while the RHS gives H1B. The RHS advises winter protection and indoor winter storage in cold areas.

Use it beneath taller plants, along shaded borders, or in groups. Containers, hanging baskets, and terrariums suit its low, trailing form. It also fits woodland gardens, rain gardens, and greenhouse displays. Its fine texture adds contrast without relying on flowers. Slugs and snails may damage the foliage. The RHS reports few disease problems. Dry soil and direct sun are poor growing conditions.