Common Name: blue oat grass
Type: Ornamental grass
Family: Poaceae
Zone: 4 to 8
Height: 2.00 to 3.00 feet
Spread: 1.50 to 2.00 feet
Bloom Time: June
Bloom Description: Bluish brown
Sun: Full sun
Water: Dry to medium
Maintenance: Low
Flower: Showy
Leaf: Colorful
Other: Winter Interest
Tolerate: Deer, Black Walnut, Air Pollution
Culture
Easily grown in average, dry to medium, well-drained soil in full sun. Best blue color occurs in dryish soils. Remove withered leaves as they appear. Although foliage is evergreen in warm winter climates, it is more semi-evergreen in harsh winters where foliage decline will occur. In the St. Louis area, plants generally benefit by being cut back close to the ground in late winter every year.
Noteworthy Characteristics
Helictotrichon sempervirens, commonly called blue oat grass, is a clump-forming, cool season, ornamental grass which typically grows 2-3' tall (foliage clump to 2' and flower stem brings total height to 3') with a similar spread. Features very narrow (3/8" wide), spiky, steel blue leaf blades (to 18") which form a rounded, porcupine-like clump. Resembles blue fescue (Festuca glauca), but is significantly larger. Spikelets of bluish-brown flowers arranged in open, one-sided panicles arching at the tip appear on erect stems rising well above the foliage clump in June. Flower spikelets mature to a golden wheat color by fall.
Genus name comes from the Greek helictos meaning twisted and trichos meaning a hair for the twisted base of the awns.
Specific epithet means ever green.
'Saphirsprudel' typically grows 2-3' tall (foliage clump to 18" with flower spikes rising above the foliage to 24-36"). Primarily differs from the species by having slightly wider leaf blades, better blue color, better disease resistance (especially to rust) and better tolerance for heat and humidity. This cultivar is sold under its original German name of 'Saphirsprudel' as well as under various translated cultivar names such as 'Sapphire' and 'Sapphire Fountain', all of which are synonymous.
Problems
Rust may be troublesome in humid climates, although this cultivar is reportedly resistant. Crown rot may occur in moist, poorly drained soils.
Uses
Specimen for the border or rock garden. Mass for ground cover. Effective foundation plant as an accent or in conjunction with dwarf blue spruces or junipers. Blue foliage contrasts well with pink flowering perennials and many spring bulbs.