Sweetgrass

Herbaceous

Sweetgrass

Hierochloe odorata

Also known as: Holy Grass, Vanilla Grass

Herbaceous Poaceae OrnamentalMedicinalGround CoverBorder Plant
Hardiness Zone
3-9
Ideal Temp
35–80°F
Survives Down To
-40°F
Life Cycle
Perennial

Sweetgrass (Hierochloe odorata) is a cool-season perennial grass of northern North American wetlands and moist meadows, spreading by rhizomes into aromatic mats traditionally braided and dried for ceremony and craft. Leaves emit a vanilla-like scent when crushed or dried. It prefers moist, sunny to partly sunny sites and asks for respect as a culturally significant plant—harvest ethically and legally. ☀️💧 Sun and Water Requirements: Full sun to light partial shade; moist soils with steady moisture through the growing season suit it best. Tolerates short dry spells once established but declines on drought berms without irrigation. Avoid stagnant, anaerobic muck; improve percolation or raise crowns slightly. ✂️ Propagation: Divide rhizomes in early spring; keep moist until rooted. Sow seed with cold-moist stratification for uniform germination. 🌾 Harvest / Best Use Timing: Harvest leaves for braiding when aromatic oils peak—follow Indigenous protocols and local regulations where applicable. Never harvest from fragile public stands without permission. Growth peaks in cool, moist periods of the year.

Good Neighbors
  • Swamp Milkweed — milkweed neighbor in moist pollinator strips
  • Marsh Blazingstar — upright forb contrast above low sweetgrass mats
  • Wild Bergamot — aromatic forb neighbor extending pollinator hours
Cautions
  • Cultural significance—avoid treating as mere “craft supply” without community context
  • Rhizome spread—edge beds or accept expansion into paths
Known Threats — Organic Solutions Only
Aphids
Aphidoidea
Armyworms
Spodoptera spp.
Bamboo Mite
Schizotetranychus longus
Corn Earworm
Helicoverpa zea
Fall Armyworm
Spodoptera frugiperda
Japanese Beetles
Popillia japonica
Leaf Blight
Various Fungal Pathogens
Lubber Grasshopper
Romalea microptera
Rice Blast Fungus
Magnaporthe oryzae
Rice Water Weevil
Lissorhoptrus oryzophilus
Spider Mites
Tetranychidae
Spittlebugs
Cercopidae
Wireworm
Elateridae (larvae; e.g., Agriotes spp.)