Arrhenatherum elatius Seeds | Tall Oatgrass
LATIN NAME: Arrhenatherum elatius
COMMON NAME: Tall Oatgrass, False Oat-Grass
Plant Profile
Tall oatgrass is a loosely tufted perennial of hay meadows, roadsides and rough grassland across Europe, western Asia and North Africa. It grows one to 1.8 metres tall, with broad, rough, grey-green blades and loose, nodding panicles of oat-like spikelets that turn pale gold in midsummer.
The stems are hollow and smooth, and the base of the plant swells into a small corm-like tuber in some forms, which is how the variegated cultivar survives grazing. It is one of the first grasses to grow in spring, which is why it was valued in hay mixtures and why it can look coarse by the time the meadow is cut.
Science & Biotechnology
The species is a model in grassland ecology. Its early growth and tall habit made it a dominant grass of traditional hay meadows, and its decline in heavily fertilised or early-cut leys has been used to track changes in agricultural practice.
Research on the genus has looked at the corm-like swellings at the base of the stem, at seed dormancy, and at the plant’s response to cutting date. Restoration seed mixes now include it to rebuild the structure of species-rich meadow, though it can dominate if the soil is too rich.
Uses & Benefits
In agriculture it is a productive forage grass, cut for hay or silage in late spring, though its feed value drops quickly once it flowers. In the garden it is grown as an ornamental grass for the loose, oat-like heads, and the variegated form, with white-striped leaves, is a useful plant for a dry border.
It is also a component of wildflower meadow sowings, where its height gives structure and its early growth shelters small plants. In parts of North America and Australia it is an invasive weed of grassland, spreading by seed along roads and railways and displacing native bunch grasses.
In a hay meadow it should be cut after the seed has set, or the stand thins within a few years.
Growing from Seed
Sow in spring or autumn, one centimetre deep, in a free-draining mix at 15-20C. Germination is quick and reliable. The plant establishes fast and can be planted out within a season; it prefers full sun and does not tolerate deep shade or waterlogging.
Cut back the old growth in late winter to make room for the new shoots, and deadhead before the seed drops if you do not want it to spread. On rich soil the stems flop after flowering, so a lean site or a position among other tall plants keeps it upright.
In a small garden, site it where its self-sown seedlings can be mown off.
Mow or graze the stand after flowering to keep it from lodging.
Our Take
Tall oatgrass is a grass of the meadow rather than the border, but its early growth and oat-like heads give it a place in a wild garden. It is easy, vigorous and hard to remove once settled.
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