How to Grow Sweetgrass
Hierochloe odorata
Sweetgrass is a flat-bladed, fragrant native grass that smells of vanilla and fresh hay — the scent is strongest when leaves are dried or crushed. It spreads steadily by rhizomes to form a fragrant groundcover in moist, semi-shaded or sunny positions. Plant in consistently moist, slightly acidic soil. It is slow to establish in the first year but spreads reliably thereafter. Cut back in late winter before new growth appears. Harvest leaves for drying or basket weaving in mid-summer when leaves are at their longest. Of deep cultural significance to Indigenous peoples of North America — grow it with respect.
Yearly Lifecycle
Care Essentials
Rarely needed. A light compost mulch in spring is sufficient. Avoid rich feeding which promotes lush, floppy growth. Sweetgrass naturally grows in nutrient-poor, moist soils.
Watch For
- Rust (in humid conditions)
- Slugs on young shoots in spring
Companions
Blue Flag Iris, Swamp Milkweed, Joe-Pye Weed, Wild Bergamot
Care Requirements
Light
Full sun to part shade
Grows best in full sun to partial shade. Part shade is tolerated and even preferred in hot climates. Full sun needs consistent moisture to prevent drought stress.
Watering
Consistently moist soil required
Native to wetland edges and moist prairies. Keep soil consistently moist. Does not tolerate prolonged drought. Mulch heavily to retain moisture.
Fertilizing
None needed; light compost mulch in spring
Sweetgrass is adapted to nutrient-poor, moist soils. A light compost mulch in spring is all that's needed. Rich feeding produces weak, floppy growth.
Pruning
Cut back in late winter; divide every 3-4 years
Cut to 5-8cm in late winter before new growth. Divide congested clumps every 3-4 years in spring to maintain vigour and control spread.
Spacing
45cm between plants
Space 45cm apart. Fills in over 2-3 seasons via rhizomes. Install a root barrier if planting near paths or lawn edges.
Growing Tips
Moist soil is essential
Sweetgrass is native to prairie wetlands and stream banks. It needs consistently moist soil and will struggle in dry conditions. Mulch to retain moisture.
Harvest for drying in midsummer
Cut long leaves in July-August before they begin to dry naturally. Bundle loosely and hang in a warm, airy place to dry. The vanilla scent intensifies as they dry.
Control spread if needed
Sweetgrass spreads by underground rhizomes and can spread vigorously in ideal conditions. Install a root barrier or lift and divide annually to control spread.
Cultural significance
Sweetgrass holds deep spiritual and cultural importance for many Indigenous peoples of North America. It is one of the four sacred medicines in some traditions. Grow with awareness of this heritage.
