Hierochloe odorata

RHS Plant Profile
holy grass

Other common names

northern holy grass, Seneca grass, vanilla grass, zubrovka

Synonyms

Hierochloe borealis

Grass Like

A very rare native grass found only in a few spots in Scotland and Ireland. Best known for its strongly scented leaves, reminiscent of vanilla or new-mown hay, leading to its use in ceremonies and as a strewing herb in countries where it is more widespread. It grows as compact tufts up to 50cm tall spreading via rhizomes to create dense patches or mats. Flowers comprising open sprays of rather rounded, greenish-brown spikelets appear in spring

Position

Full sun, Partial shade

Soil Types

Clay, Loam

Size

Time to Maturity
2–5 years

Growing Conditions

Clay Loam
Moisture
Moist but well–drained
pH
Neutral

Position

Full sun Partial shade
Aspect
East–facing or North–facing or South–facing or West–facing
Exposure
Exposed or Sheltered
Hardiness
H7

Colour & Scent

Fragrance Foliage
Season Stem Flower Foliage Fruit
Spring
Summer
Autumn
Winter

Botanical Details

Family
Poaceae
Native to GB/Ireland
Yes
Foliage
Deciduous
Habit
Tufted
Genus
Name Status
Correct

How to Grow

Cultivation

Found in wet, grassy places and prefers moist but well-drained, more or less neutral soil in sun or partial shade

Propagation

Propagate by seed or by division

Suggested planting locations and garden types

  • Cottage and informal garden
  • Wildflower meadow
  • Wildlife gardens

Pruning

No pruning required, can be tidied after flowering

Pests

Generally pest-free

Diseases

Generally disease-free