Avenella flexuosa
wavy hair-grass
Northern Hemisphere (Europe, northern Asia, North America)
Overview
Avenella flexuosa is a densely tufted, semi-evergreen perennial grass forming low clumps of slender, hair-like leaves 4-12 inches (10-30 cm) tall. In early to midsummer it throws up slender flowering stems to 24-32 inches (60-80 cm), each carrying an airy, open panicle of silvery to purple-bronze spikelets on wavy, almost zig-zag branches that give the plant its name. The thread-like basal leaves are rolled and inrolled, dark green, and persist through mild winters. It is a grass of acidic ground, growing on heaths, moorland, and the floor of open oak and pine woodland, where it can form extensive swards. The plant requires acid to neutral soil and becomes chlorotic and short-lived on chalk or limestone. After flowering the panicles fade to a pale straw colour and the clump can look untidy until cut back. It spreads slowly by short rhizomes and self-seeds in suitable acidic ground, but it does not run aggressively. Growth is densest in cool, moist conditions with some shade, and clumps thin out in hot, dry, exposed positions.
Native Range
Avenella flexuosa has a wide distribution across the cool temperate Northern Hemisphere, native through Europe, northern and central Asia, and North America. It grows on acidic soils in heathland, moorland, and open coniferous and oak woodland.Suggested Uses
Grown in woodland gardens, heath and gravel plantings, and naturalistic meadows on acidic soil, spaced 12-15 inches (30-38 cm) apart. Suits massing as a soft groundcover grass and underplanting acid-loving shrubs such as rhododendrons. The airy panicles are also cut for arrangements.How to Identify
Appearance
Size & Dimensions
Height4" - 2'8"
Width/Spread1' - 1'6"
Reaches mature size in approximately 2 years
Bloom Information
The grass flowers from June into July, lifting airy panicles well above the leaf tufts. Spikelets open silvery-purple and age to straw as seed ripens through late summer. The dried flowering stems can persist into autumn.
Detailed Descriptions
Foliage Description
Dark greenGrowing Conditions
Sun Requirements
Requires 3-8 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
Care & Maintenance
Care Guide
Grow in acid to neutral soil in part shade to full sun, with steady moisture and free drainage. The plant requires lime-free ground and yellows on chalk or limestone, so it suits woodland edges, heath gardens, and acidic beds. Water through dry spells, as prolonged drought thins the clump and browns the foliage. Cut the old flowering stems and tired leaves back in late winter before new growth begins. No feeding is needed on its natural lean, acidic soils, and rich ground produces lax growth. It is hardy in USDA zones 4 through 9 and needs no winter protection.Pruning
Cut the clump back to a few inches in late winter to clear spent stems and old foliage before fresh growth. Comb out dead leaf blades by hand during the season to keep the tuft tidy. No other pruning is required.Pruning Schedule
J
F
M
A
M
J
J
A
S
O
N
D
winter
Container Growing
✓ Suitable for container growing
Minimum container size: 2 gallons