What: The narrow, spiky, gray-blue foliage of Helictotrichon sempervirens forms a small, architectural mound and is particularly handsome in summer when the purplish-brown seed heads top the leaf blades; by autumn these oat-like spikelets mature to a fetching wheat color. Also known as blue oat grass, it grows fine in most well-drained soils, but also does well in poor, dry soil conditions and is drought tolerant once established. Plant as a single groundcover or mix with low-growing shrubs such as heaths and heathers.
Where: This evergreen grass prefers a location in full sun with well-drained or sandy soil. Once established, it is fully drought tolerant.
Size: The plant grows to be 2 feet tall and 2 feet wide when mature.
Care: It does not respond well to cutting back. Instead, comb out old and dead grass blades by hand or with a hand rake in late winter.
— Richie Steffen, Great Plant Picks