Content Detail

Blue oat grass is a cool season clumping grass with blue foliage, attractive flowers, and a mounded form.

  • Family (English) Grass
  • Family (botanic) Poaceae
  • Tree or plant type Grass, Perennial
  • Native locale Non-native
  • Size range Large plant (more than 24 inches)
  • Light exposure Full sun (6 hrs direct light daily)
  • Hardiness zones Zone 4, Zone 5 (Northern Illinois), Zone 6 (City of Chicago), Zone 7, Zone 8, Zone 9
  • Soil preference Moist, well-drained soil
  • Season of interest early winter, midwinter, late winter, early spring, mid spring, late spring, early summer, midsummer, late summer, early fall, mid fall, late fall
  • Flower color and fragrance Blue
  • Shape or form Mounded, Upright

Size and form:

Blue oat grass grows as an upright tuft or mound, reaching a height of 2 to 3 feet when in flower.

Native geographic location and habitat:

This plant is native Europe and Asia.

Leaf or needle arrangement, size, shape, and texture:

The metallic blue leaves which hold their color all year are 1/4 to 1/8 inch wide and 12 to 18 inches long.

Flower arrangement, shape, and size:

The tiny, blue-white flowers appear from late spring to early summer and are in oat-like clusters held on one side of the flower stalk.

Fruit, cone, nut, and seed descriptions:

The small fruit (caryopsis or grains) form in the oat-like clusters that hold the flowers and turn tan when mature.

Plant care:

Blue oat grass does best in planted full sun and moist, well-drained soil. If planted in wet, clay soils it may get root rot. This grass does not tolerate hot, humid summers and flowering may be reduced under those conditions. Good air circulation is needed to minimize a fungal rust disease. Since this is a cool season grass, its most active growth occurs in spring and fall. It will remain semi-evergreen in winter and can act as winter interest. Blue oat grass remains semi-evergreen through winter and it should not be cut back to the ground until early spring, before new growth begins.

List of pests and diseases:

A fungal rust disease can occur in wet, humid conditions.

Saphirsprudel (Saphire Fountain) blue oat grass (Helictotrichon sempervirens ‘Saphirsprudel’):

This cultivar with steel blue leaves is more tolerant of heat and resistant to rust disease.


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