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ornamental grass

Blue oat grass

Helictotrichon sempervirens

Preview: plant data is awaiting horticulturist review. A professional horticulturist hasn't reviewed our plant table yet. Lists still follow fixed rules for zone, sun, pets, deer and invasive status.

Blue oat grass is a semi-evergreen ornamental grass hardy in zones 4–8. It grows 2–3 ft tall and 2–2.5 ft wide, so plant it 2 ft apart. Give it full sun and little water once established. It is grown for its foliage rather than its flowers. In a FloraVista list it usually plays the grass role: a grass or grass-like plant that adds movement and fine texture in the middle. Deer usually leave it alone, and it is not listed as toxic to dogs or cats. Our rules leave it out of lists in the Southeast, Florida and the Gulf and Texas and the South-Central states, where summer heat, humidity or mild winters hold it back even inside its zone range.

Facts from our plant table

Botanical name
Helictotrichon sempervirens
Plant type
Ornamental grass, semi evergreen
Hardiness zones
4 to 8
Sun
Full sun (6+ hours)
Water
Low
Soil
Well-drained soil; crown rots in wet clay.
Mature size
2–3 ft tall × 2–2.5 ft wide
Spacing
2 ft apart (centre to centre)
Growth rate
Medium
Bloom
Grown for foliage
Roles in a bed
Grass
Styles
modern, low water
Deer resistance
High: deer rarely eat it
Pets
Not listed as toxic to dogs or cats
Native to
Not native to the US (or a garden hybrid)
Pot size and price
1-gallon pot, typically $10–$18 (sometimes stocked)
Plant in
Spring or Fall
First-year watering
Water deeply once or twice a week for the first 6-8 weeks, then every 10-14 days in dry spells through the first summer; after that only in long droughts.
Pruning
Comb out or trim tired leaves in early spring; do not cut into the crown.

Sources: Missouri Botanical Garden Plant Finder; state extension service fact sheets; ASPCA toxic and non-toxic plant list (true grasses and sedges are not listed as toxic); Rutgers NJAES deer resistance ratings; state extension service; Invasive Plant Atlas of the United States; state noxious weed and invasive plant lists; US garden-centre and home-improvement retail listings (general knowledge, 2026 estimate). Not yet reviewed by a horticulturist.

Guides that include this plant

Good companions

The plants our list engine most often puts in the same bed as Blue oat grass, across the sun, zone, pet, deer and style combinations it fits.

If you can't find it

Plants that do the same job and pass the same rules for the conditions Blue oat grass suits.

How this page was made

This page was generated from this plant's record in FloraVista's plant table by fixed rules. The companions and substitutes come from the lists our rules engine composes. No named expert has reviewed this page.

Data status: the plant table is awaiting review by a horticulturist. Check each plant with a local nursery or extension office before you buy.

Sources

  • Missouri Botanical Garden Plant Finder, state extension services and the USDA PLANTS database (zones, size, sun, water, bloom, native range)
  • ASPCA toxic and non-toxic plant lists (dog and cat toxicity)
  • Rutgers NJAES and regional extension deer-resistance ratings
  • State noxious-weed and invasive-plant lists and the Invasive Plant Atlas of the US
  • Typical US garden-centre listings (pot size and price band)

Generated . How FloraVista chooses plants