Overview
Bromus sterilis (syn. Anisantha sterilis) is a winter annual grass in the Poaceae family, growing 12–36 inches (30–90 cm) tall in loose tufts. Stems are erect to ascending, slender, smooth, with 3–5 nodes. Leaves are flat, 2–5 mm wide, softly hairy on both surfaces, bright green. Leaf sheaths are closed at the base, softly pubescent. The inflorescence is an open, nodding panicle 4–8 inches (10–20 cm) long with long, drooping branches bearing large spikelets 1–2 inches (2.5–5 cm) long (excluding awns). Each spikelet contains 4–8 florets with long, straight awns 0.6–1 inch (15–25 mm) long — the long-awned, drooping spikelets are the primary identification character. The epithet sterilis refers not to the plant's fertility (it produces abundant seed) but to its perceived worthlessness as a forage grass — livestock avoid it once the awns harden. Native to Europe, western Asia, and North Africa, the species is one of the most common weeds of arable field margins, roadsides, railway embankments, and disturbed urban ground in temperate regions. It germinates in autumn, overwinters as a small tuft, and flowers the following spring-summer. In the Pacific Northwest, it is abundant on roadsides and in urban waste ground. The hard, retrorsely barbed awns can cause eye, skin, and mouth injuries in dogs and livestock.
Native Range
Bromus sterilis is native across Europe, from the British Isles and Scandinavia south to the Mediterranean, and east through the Caucasus, western Asia, and North Africa. Widely naturalised in temperate North America, Australia, and New Zealand.Suggested Uses
Not recommended for intentional garden planting. The species is an ecological component of ruderal and disturbed-ground communities in its native European range. Used occasionally in ecological research and in seed mixes for temporary cover on construction sites, where its rapid establishment stabilises bare soil during the first winter. In habitat restoration, it is typically replaced by perennial native grasses as the site matures.How to Identify
Appearance
Size & Dimensions
Height1' - 3'
Width/Spread4" - 8"
Bloom Information
Panicles emerge from May through June. The open, drooping panicle sheds pollen by wind over a 2–3 week period. Spikelets ripen from green to straw-coloured by late June–July. Awned seed is dispersed by wind, animal attachment, and gravity. The plant dies after seed set.Detailed Descriptions
Flower Description
Green aging to straw-colouredFoliage Description
Bright greenGrowing Conditions
Sun Requirements
Requires 4-10 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
Drought Tolerance
Drought tolerant when established
Care & Maintenance
Care Guide
Not cultivated intentionally. Where it occurs as a weed, management involves preventing seed set by mowing or hand-pulling before panicles ripen in June. Autumn-germinating seedlings can be controlled by shallow cultivation or targeted herbicide application. Improving soil fertility and establishing competitive perennial groundcover reduces establishment. In ecological study areas, it is sometimes maintained as a component of ruderal plant communities.Pruning
Not applicable in a horticultural context. For weed management, mow or pull plants before seed maturity in June.Maintenance Level
very low⚠️ Toxicity Warning
Non-toxicPlanting Guide
Planting Methods & Timing
Planting Method
direct sow
Days to Maturity
180–240 days