Grass · Poaceae family
Blue Oat-grass
Helictotrichon sempervirens
In short a 10-second read
Blue Oat-grass (grass) grows to 0.6–0.9 m tall and 0.5–1 m wide when mature. It grows best in full sun, in dry to average soil. Hardy to −34 °C.
× spread 0.5–1 m
Where to plant
Sun, soil, frost.
It grows best in full sun, in dry to average soil. Hardy to −34 °C.
Sun
Elsewhere it will grow less well.
Soil and water
dry to average · watering: little
Soil: gravelly, sandy, loamy
Frost
It copes with a normal winter outdoors.
How much space it takes
Mature size.
The mature plant next to a person (175 cm).
Next to a person
Reaches maturity in about 2–5 years. The final size depends on the cultivar and the spot — we give the range from smallest to largest.
Calendar
What to do and when.
Months for Central Europe. The line shows the current month.
The year at a glance
Pruning
No pruning needed — just remove dead or damaged parts (February–March).
Planting
container plant: March–May, September–October
Winter protection
not needed
Overwintering
It copes with winter on its own.
It overwinters outdoors without protection, hardy to −34 °C.
- Needs no protection
- Hardy to −34 °C
- Evergreen — green in winter too
What to combine it with
Same needs, different flowering.
They share the same sun and soil and flower in other months — so the bed flowers for longer.
Common Poppy
0.23–0.45 m
common yarrow
0.4–0.8 m
giant onion
0.9–1.5 mReady-made Studio combinations that include Blue Oat-grass
Blue globe thistles and sea holly over grey grass and houseleeks —…
Frequently asked
Quick answers.
Does Blue Oat-grass tolerate shade?
No, it needs full sun.
How much space does Blue Oat-grass need?
At maturity 0.5–1 m wide and 0.6–0.9 m tall; recommended spacing 58 cm.
Does Blue Oat-grass survive winter outdoors?
Yes, without protection, hardy to −34 °C.
Where the data comes from
We compared the data in 23 expert sources. Last checked 28 September 2026.
Show sources (23)
- GBIF Backbone Taxonomy — Helictotrichon sempervirens
- GBIF Occurrence Search API — Helictotrichon sempervirens
- GBIF Vernacular Names API — Helictotrichon sempervirens
- Wikidata (CC0) — Helictotrichon sempervirens
- Missouri Botanical Garden Plant Finder — Helictotrichon sempervirens
- NC State Extension Gardener Plant Toolbox — helictotrichon sempervirens
- EPPO Global Database — Helictotrichon sempervirens
- Pollen.lu — Réseau luxembourgeois de surveillance pollinique
- Allergieinformationsdienst (Helmholtz Munich) — Heuschnupfen: Gräserpollen ako spúšťač alergickej rinitídy
- RHS Plant Finder
- Sarastro Stauden, katalóg
- Bamberger Staudengarten (Strobler), katalóg
- Foerster-Stauden, katalóg
- RHS - How to grow ornamental grasses
- Iowa State Extension - How to Plant Perennials
- RHS - Ornamental grasses: cutting back
- Invasive plant lists — this species is not on them: EASIN, EU, Slovakia, Czechia, Germany, Poland, Denmark
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