Sweet Grass

Hierochloe odorata

herb

Sweet grass (Hierochloe odorata), also called holy grass or vanilla grass, is a slender, cold-hardy native perennial grass prized not for looks but for scent: as it dries it releases a sweet, long-lasting vanilla-like fragrance from the coumarin in its blades. It is deeply important in many Indigenous North American cultures, where the long blades are harvested, dried, and braided for ceremony and basketry. Growing about 1 to 2 ft, it spreads by creeping rhizomes into a loose patch in moist, sunny ground. It rarely sets viable seed, so it is grown from plugs or divisions, and it makes a fragrant, low-care groundcover.

✅ Plant alongside

Good neighbors that attract beneficial insects or deter pests

• Bee Balm — A moisture-loving companion for a damp, sunny native bed
• Boneset — Shares the wet ground and the two suit a rain-garden or native planting together
• Yarrow — A tough herb that fills in around the spreading grass and draws beneficial insects

🛡️ Pest & disease prevention

Proactive ways to stop trouble before it starts — tap a name with an arrow for its full guide

• Rust →

  Grass rusts can spot the blades in humid spells - give airflow and avoid overhead watering

• Aphids →

  Rarely serious; rinse off the occasional colony

🌾 Harvest & storage

Harvest the long blades through the growing season by cutting or pulling them near the base, taking the longest leaves; they can be gathered repeatedly as the patch regrows. The scent develops as the grass dries, so cut the blades and dry them flat or braided in a shaded, airy place, where the vanilla fragrance deepens and lasts a long time. Avoid cutting the whole patch to the ground at once so it keeps spreading.

🥗 Nutrition & benefits

Sweet grass is not a food plant - it is grown and harvested for the sweet, vanilla-like fragrance its dried blades release, traditionally braided and used in ceremony, smudging, and basketry by Indigenous peoples. In the garden it is a fragrant, cold-hardy native groundcover for moist, sunny ground.