Blue Oat Grass
Helictotrichon sempervirens
Evergreen, Blue Oat Grass, Helictotrichon sempervirens, is a cool season, clump-forming grass with steel-blue foliage. This is an award-winning plant for any garden. It won the Award of Garden Merit from the Royal Horticultural Society in 1993 and was selected for Great Plant Picks in 2004.
The neat, bristly mounds make an attractive ornamental plant. Perennial grass is hardy in zones 3 or 4-8. The long, wiry leaves on arching stems are about ½ inch wide and taper to a fine point. Under optimal conditions it grows about two feet tall and three feet wide.
Graceful flower plumes grow vertically from the center of the plant. Flowers bloom beige in midsummer and move in the wind. flowers persist through the fall. Cut off when break. The seeds do not seed around.
This small ornamental grass has many landscape uses, with a color and texture few plants have.
It makes a nice addition to the perennial border, particularly as a contrast to green-leaved plants. Use it as a single accent plant in the smaller garden or rock garden, grow it in masses for a fine-textured drift, or try it in a container. BlueOat Grass makes a nice row along a walkway, or can be added to the front of a shrub border. It combines well with Russian sage (Perovskia), Salvia x sylvestris ‘Mainacht’ (‘May Night’), blanketflower (Gaillardia), Sedum ‘Autumn Joy’ and other, more upright ornamental grasses. Use it to echo the blue foliage or flowers of blue spruce, blue junipers or blue-flowering perennials such as Campanula, lavender (Lavendula), or blue mist spirea (Caryopteris). For a more dramatic effect, try combining it with plants with deep maroon leaves.
Plant blue oat grass in full sun. Well-drained soil is essential for winter survival. Although it prefers a moist soil, it will tolerate sandy as well as heavy clay soils – as long as it does not remain too wet in winter. Evergreen in milder climates.
CARE: Use a rake or gloved hand to remove the old foliage in late winter. Cut off bent flower spikes. Do not cut grass all back. Good drainage needed.