OnMySill

Blue Fescue / Blue Mountain Grass

Festuca glauca

description

Blue Fescue is a compact ornamental grass forming fine blue-grey tussocks.

benefits

  • Suitable for containers

How to care for Blue Fescue

sunlight

Blue fescue comes from open, sunny grasslands and rocky slopes. Give it the brightest spot you have so its compact clumps keep their blue-grey colour.

Full sun

Plant outdoors where it receives about 6 or more hours of direct sun daily. It can tolerate light afternoon shade, especially in very hot climates, but too much shade makes growth greener, looser, and less vigorous.

If the blue colour fades or the clump leans and opens up, move it into more direct sun.

watering

Water deeply, then let the soil dry well before watering again. Blue fescue is drought tolerant once established and quickly declines in soggy soil.

Spring and summer

For a potted plant, water about every 7-14 days in warm, dry weather. Check first: water only when the mix is dry at least halfway down and the pot feels light. In the ground, water during prolonged dry spells, especially in its first growing season.

Autumn and winter

Growth slows in cool weather, so a container may need water only every 2-4 weeks if sheltered from rain. Do not water frozen soil. Rain, low light, a large pot, and a moisture-retentive mix all lengthen the interval.

Use a pot with drainage and a gritty mix. Keep water away from the crown rather than leaving the clump sitting wet.
Constantly wet soil can rot the roots and cause the blue foliage to thin or brown.

humidity

Preferred humidity

30-45%

Blue Fescue comes from dry, open ground and is happiest in ordinary, well-ventilated air. Typical homes at about 25-50% relative humidity are suitable, and it does not need misting or a humidifier.

Keep the foliage dry and give the clump good air circulation.

Prolonged humid, stagnant air can encourage fungal problems, especially if the soil stays wet. Very dry air alone rarely causes trouble, but crisp brown tips together with dry soil mean it needs a thorough drink rather than extra humidity.

temperature

Best growth

10-24°C (50-75°F)

Potted plants in winter

Shelter below -10°C (14°F)

Blue Fescue is a cool-season grass from sunny, well-drained European grasslands. It grows best in mild spring and autumn weather, and can fade or thin during prolonged heat above 27°C (80°F), especially where nights stay warm and humid. Established plants are hardy in the ground, but container roots need protection during severe freezes.

Place pots where they receive winter shelter but still stay outdoors in cool weather.

nutrition

March - August

Blue fescue is a light feeder and keeps its best compact blue-grey form in lean soil. Feed once in early spring with a balanced slow-release fertiliser at about half the label rate. For plants in pots, a half-strength liquid feed about every 6-8 weeks is enough while they are actively growing. Do not feed in autumn or winter, and skip feeding if growth is already dense and healthy.

Nitrogen

Nitrogen supports fresh leaf growth, but too much makes this grass soft, green and floppy. A gentle, balanced feed provides enough without sacrificing its tidy colour and shape.

Apply fertiliser to already-moist soil, then water lightly to spread it through the root zone.

soil

Gritty, fast-draining soil

Blue fescue prefers lean, airy soil that dries freely around its roots. Use a general potting mix loosened with about one-third horticultural grit, coarse sand, or perlite, and avoid heavy, rich mixes that stay wet.

pH 6,0 - 7,5

This is slightly acidic to slightly alkaline, a range most ordinary garden soil and potting mixes suit well. Do not add acidifiers unless you know your soil is strongly alkaline; good drainage matters far more.

Choose a pot with drainage holes and never let it sit in a saucer of water.