Helictotrichon sempervirens 'Sapphire' – Blue Oat Grass

Add bold steel-blue texture and airy movement to sunny borders with 'Sapphire' Blue Oat Grass.

Helictotrichon sempervirens 'Sapphire' is a cool-season perennial ornamental grass that forms rounded clumps of narrow, arching blue foliage. Tall flower stems rise above the leaves in late spring and early summer, carrying oat-like flower heads that mature to warm straw tones. Use it as a focal point in a gravel garden, repeat it through a sunny border, or pair it with warm-colored flowers for a striking contrast. Its substantial mound provides structure without a running growth habit. Give it well-drained soil and good air circulation, avoiding persistently wet conditions, especially in winter. Once established, it tolerates periods of drought and performs best where summers are not excessively hot and humid.

Key Features

• Plant type: Cool-season perennial ornamental grass
• Narrow steel-blue foliage forms rounded, arching clumps
• Tall, oat-like flower heads mature to straw tones
• Evergreen to semi-evergreen, depending on climate
• Useful for sunny borders, gravel gardens, and specimen plantings

Growing Details
Height: 2–3 ft.; up to 4 ft. in bloom | Spread: 2–3 ft.
Exposure: Full sun | Water: Low to moderate once established; provide well-drained soil
Bloom time: Late spring to early summer | Bloom color: Pale tan to purplish, aging straw-gold
USDA hardiness zones: 4–9