Arrhenatherum elatius
tall oat grass
Overview
Arrhenatherum elatius, false oat-grass, is a tall, tussock-forming perennial grass in the family Poaceae, growing 24-72 inches (60-180 cm) tall in loose clumps. The flat, grey-green leaf blades are rough to the touch, and the stems rise well above the foliage to carry the flower heads. From late spring into summer it produces open, nodding panicles 4-12 inches (10-30 cm) long, shining green tinged with purple, the spikelets bearing slender bent awns that catch the light. It grows in rough grassland, road verges, hedge banks, railway sides, and meadows on most fertile soils, and is a dominant grass of ungrazed lowland verges. A form with a chain of swollen, onion-like corms at the stem base, known as onion couch, spreads from these corms and persists as a difficult weed in cultivated ground. The plant is wind-pollinated and sets abundant seed, dispersing widely along disturbed corridors. It dies back to the tuft over winter and regrows in spring. Coarse growth and free seeding can let it crowd out smaller grasses and wildflowers in unmanaged grassland.
Native Range
Native to Europe, North Africa, and western Asia, where it grows in meadows, rough grassland, scrub edges, and along tracks and verges on a wide range of soils. It has naturalized across North America, Australia, and other temperate regions, where it is often regarded as invasive.Suggested Uses
Grown in wildflower meadows, naturalistic grassland, and conservation plantings where a tall, airy grass structure is wanted. Used for erosion control and quick cover on banks, verges, and disturbed ground. Its coarse growth and free seeding make it unsuited to small borders or managed ornamental lawns.How to Identify
Appearance
Size & Dimensions
Height2' - 6'
Width/Spread1' - 2'
Colors
Bloom Information
The grass flowers from May through July, the panicles opening loose and nodding as the awned spikelets mature. Pollen is shed to the wind, with no scent or nectar to draw insects. Ripe seed falls through summer and is carried along verges and disturbed ground.
Detailed Descriptions
Foliage Description
grey-greenGrowing Conditions
Sun Requirements
Requires 5-9 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
