Polytrichum formosum
bank haircap moss
Europe, Asia, North America (Holarctic)
Container Friendly
Native to North America
SunPart Shade – Full Shade
WaterMedium
Overview
Polytrichum formosum is a tall, upright acrocarpous moss of the family Polytrichaceae, forming loose green turfs of unbranched stems 1-5 inches (2-12 cm) high. The stiff, lance-shaped leaves spread outward when moist and press against the stem when dry; their upper surface carries narrow longitudinal ridges, or lamellae, that increase the photosynthetic area. Unlike most mosses, it has internal conducting strands that move water and food along the stem, allowing it to grow taller than cushion-forming species. Male plants form rosette-like splash cups at their tips, while fertilised female stems raise rectangular, sharply angled spore capsules on long reddish stalks, each capsule capped by a golden, hairy hood. It anchors by rhizoids in acidic, humus-rich soil and has no roots, flowers, or seeds. The moss grows on woodland banks, heaths, and shaded acid ground, spreading slowly into wide patches. It needs steady moisture and cool shade, thinning and browning where soil is dry, limy, or sun-baked. Old stems persist below the green tips, building a deep, springy layer over time.
Native Range
Native across Europe, temperate Asia, and North America, with a broad Holarctic distribution on acidic soils. It grows on woodland banks, heathland, moorland, and shaded hillsides, common in cool, humid regions.Suggested Uses
Grown in woodland and shade gardens, moss gardens, and terrariums as a tall, textured green carpet on acidic ground. It suits naturalistic plantings under trees and on shaded banks where grass grows poorly. The deep turfs hold soil on slopes and add winter greenery to shaded beds.How to Identify
Growing Conditions
Sun Requirements
Requires 2-5 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight
Water & Climate
Water Needs
Care & Maintenance
Care Guide
Growth is strongest in cool, shaded, consistently moist conditions on acidic, humus-rich soil, such as woodland floors and shaded banks. The moss takes up water across its leaves and through internal strands, so it depends on humidity and a damp rooting layer. In dry or sunny spots the leaves curl and brown, recovering after rain but growing slowly. Limy soils and deep drought both check it. In cultivation it is grown from transplanted turfs or scattered fragments pressed onto bare acid soil and kept damp and shaded until established. It needs no feeding and no winter protection, staying green through cold weather.Container Growing
✓ Suitable for container growing
Minimum container size: 1 gallons