Leymus spp.
Overview
Leymus spp. is a genus of perennial cool-season grasses in the family Poaceae, comprising about thirty to forty species native across temperate Eurasia and North America. Plants range from compact tufts to tall, strongly rhizomatous colonies, with foliage from 30 cm to 1.5 m (12 in to 5 ft) and flowering stems reaching 0.5–2.7 m (1.6–9 ft) in robust species such as L. cinereus. Many species, including L. arenarius and L. mollis, carry stiff, flat to inrolled blades in shades of blue-grey to grey-green and spread by thick creeping rhizomes that bind loose sand and soil. The flowers form a dense, erect terminal spike 10–35 cm (4–14 in) long with paired spikelets, ripening to wheat-like seed heads. Leymus spp. grows in full sun on free-draining sandy or rocky ground, tolerates wind, salt spray, and drought, and recovers from burial by drifting sand. The same vigorous rhizomes that stabilise dunes also let it spread well beyond its planted position, so it can crowd smaller plants in a border. Foliage colour and habit vary by species and conditions, with the bluest tones developing in full sun on lean soils.
Native Range
Leymus spp. species are native to temperate coasts, dunes, steppes, and mountains of Europe, Asia, and North America. L. arenarius occurs along northern European and North Atlantic shores, while L. cinereus and L. condensatus grow in western North America from the Great Plains to the Pacific.Suggested Uses
Planted for dune and bank stabilisation, coastal and gravel gardens, and as a blue-foliage accent in borders and large containers. Massed on slopes and roadsides for erosion control. Confined where its spreading rhizomes cannot crowd smaller plants.How to Identify
Appearance
Size & Dimensions
Height1' - 9'
Width/Spread2' - 4'
Reaches mature size in approximately 2 years
Colors
Bloom Information
Grasses of Leymus spp. flower in summer, generally June to August, sending up erect spikes above the foliage. The wind-pollinated spikes shed pollen over a few weeks and dry to persistent straw-coloured seed heads. The spent spikes stand into autumn and winter.
Detailed Descriptions
Flower Description
green maturing to strawFoliage Description
blue-grey to grey-greenGrowing Conditions
Sun Requirements
Requires 6-12 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 Leymus spp. in full sun on light, free-draining sandy or gravelly soil. It tolerates drought, wind, coastal salt, and poor infertile ground, and the blue-leaved species keep their strongest colour on lean dry soils. Rich or moist soils produce lax, greener growth and quicker rhizome spread. A pH range of about 6.0 to 8.0 suits most species. Plants need almost no feeding and little water once established. Rhizomatous species are contained by a root barrier or a sunken container.Pruning
Cut whole clumps to near ground level in late winter before new growth begins to clear old foliage and spent spikes. Shear or comb out dead blades on evergreen species in spring. No other pruning is needed.Pruning Schedule
J
F
M
A
M
J
J
A
S
O
N
D
winter
Container Growing
✓ Suitable for container growing
Minimum container size: 5 gallons