Blue Hair Grass (Glaucous hair grass) care

Light

Blue Hair Grass needs sun on the leaves, not just bright ambient room light. Demands full sun for at least 6 hours per day; the blue coloration is most intense in open, sunny positions and fades noticeably in shade, where plants also become more susceptible to rot. A south or west-facing windowsill in the northern hemisphere is the default; anywhere else, expect the plant to stretch and pale out within a season.

Watering

Water blue hair grass every 2–3 weeks once established; water sparingly. The actual day count varies with pot size, light, and season — the finger test (or lifting the pot to feel its weight) is more reliable than a fixed calendar. Empty any drainage saucer afterwards so the pot isn't sitting in water. Highly drought-tolerant once established; best treated as a dry-garden or xeriscape plant — excess watering on clay soils quickly leads to crown rot and plant death.

Soil and pot

Blue Hair Grass grows best in very well-drained, poor, sandy or chalky, alkaline to neutral. Native to sandy heathland and chalk grassland; adding compost or growing in rich, moist soil shortens its lifespan significantly — infertile, gritty soil is genuinely preferable. A pot with a working drainage hole is non-negotiable for this species — even free-draining mix will turn soggy in a closed planter. If you love the look of a decorative pot without a hole, use it as a cachepot around an inner nursery pot you can lift out to water.

Humidity and temperature

Blue Hair Grass sits happiest at around Low (20–50%) humidity and -20°C to 35°C (-4°F to 95°F). Best suited to low-humidity, continental or Mediterranean climates; in high-humidity regions ensure excellent air circulation to prevent fungal crown rots. If you keep the room above year-round and avoid placing the plant near a cold draught, a hot radiator, or an air-conditioning vent, you have already handled the two biggest indoor stressors.

Fertilising

Feed blue hair grass sparingly. Do not fertilise; supplemental feeding on poor dry soils encourages lush, disease-prone growth and dramatically shortens the plant's lifespan. Skip fertiliser entirely on a stressed, recently-repotted, or actively wilting plant — fertiliser salts make damage worse, not better. Wait for a round of healthy new growth before resuming a feeding rhythm.

Common problems

Below are the issues we see most often on blue hair grass in the Growli community. Each is annotated with the most common cause so you know where to start.

• Short lifespan on rich or moist soil — Plants decline rapidly and often die within 2–3 years when grown in fertile, moist, or clay-heavy soils; grow in pure grit or alkaline sand for best longevity.
• Crown rot in wet winters — Winter wet sitting in the crown is the most common cause of sudden plant death; ensure perfect drainage and consider a gravel mulch around the crown to deflect moisture.

Propagation

Divide clumps in spring or early autumn; or sow fresh seed in late summer directly into poor, sandy soil in situ — avoid transplanting seedlings into enriched potting compost. Propagation is the cheapest, most satisfying way to expand a collection — and it doubles as insurance against losing a mature plant to an accident. Take a backup cutting once the parent is established and healthy.

Toxicity to pets

Blue Hair Grass is pet-safe. Koeleria glauca is not listed on the ASPCA Toxic and Non-Toxic Plant database as toxic to cats or dogs. No toxic principles are known in Koeleria species, which are true grasses (Poaceae) widely grazed safely by livestock. If you keep cats, dogs, or curious children in the house, weigh placement carefully — a high shelf or a hanging planter is enough for casual safety. For severe ingestion incidents, call your local vet and the ASPCA Animal Poison Control Center (in the US, 888-426-4435).

Pet-safety status is sourced from the ASPCA Toxic and Non-Toxic Plant List, which catalogues the most-asked-about plants for cats, dogs, and horses.

Blue Hair Grass deep-dive guides

Every aspect of blue hair grass care, each with its own calibrated guide:

• Common blue hair grass problems & fixes
• Blue Hair Grass watering schedule
• Blue Hair Grass light requirements
• Best soil mix for blue hair grass
• Blue Hair Grass fertilizing guide
• When to repot blue hair grass
• How to propagate blue hair grass
• How to prune blue hair grass
• What's eating my blue hair grass?
• Blue Hair Grass growth rate & size
• Blue Hair Grass cold hardiness
• Blue Hair Grass temperature & humidity
• Is blue hair grass toxic to cats & dogs?
• Is blue hair grass toxic to cats?
• Is blue hair grass toxic to dogs?
• Getting blue hair grass to bloom

Featured in these plant shortlists

Blue Hair Grass qualifies for 9 curated Growli shortlists — each one filtered objectively from our structured plant-care library, so the selection is consistent and checkable:

• Best pet-safe houseplants — Houseplants the ASPCA lists as non-toxic to cats and dogs — every one verified against the ASPCA toxic and non-toxic plant list.
• Best drought-tolerant houseplants — Houseplants that prefer to dry out — forgiving of forgotten watering and ideal for travel or busy weeks.
• Best flowering houseplants — Indoor plants grown for their blooms — selected from the flowering species in Growli’s plant-care library.
• Best pet-safe low-maintenance plants — Non-toxic to cats and dogs and forgiving of forgotten watering — the easiest safe choices for a busy pet household.
• Best pet-safe flowering plants — Flowering houseplants the ASPCA lists as non-toxic to cats and dogs — colour and blooms in a pet home, without the worry.
• Best pet-safe plants for bright light — Non-toxic to cats and dogs and happy in a bright, sunny spot — safe plants for your best-lit windowsill.
• Best houseplants for full sun — Houseplants that want direct sun — the species for a hot south or west-facing windowsill where shade-lovers scorch.
• Best cat-safe plants — Houseplants the ASPCA lists as non-toxic to cats (and dogs) — safe greenery for a home with a curious cat.
• Best dog-safe plants — Houseplants the ASPCA lists as non-toxic to dogs (and cats) — safe greenery for a home with a curious dog.
• Browse all 29 plant shortlists — pet-safe, low-light, drought-tolerant and more

Related guides

Blue Hair Grass is also known as Blue hair grass, Glaucous hair grass, and Large blue hair grass.

• Georgia Blue Speedwell care — light, water and common problems
• Blue Creeping Speedwell care — light, water and common problems
• Pink Pussytoes care — light, water and common problems
• All 10153 plant care guides in the Growli library