Sweetgrass (Hierochloe odorata) is a perennial grass known for its distinctive, sweet, vanilla-like fragrance, especially when dried. Also called vanilla grass or holy grass, it holds deep cultural importance for many indigenous communities across its native range.
Where Sweetgrass Thrives Naturally
Sweetgrass is a circumpolar plant, with its natural habitat spanning northern North America and Eurasia, including Greenland and Iceland. In North America, its distribution extends from Alaska to Newfoundland, reaching south into states such as New Jersey, Indiana, Iowa, New Mexico, and Arizona, and is found throughout the Great Lakes region and the upper Midwest.
This grass flourishes in moist, cool meadows, low prairies, and savannas. It also grows along riverbanks, lake edges, shaded stream banks, wetlands, bogs, and open woodlands. Sweetgrass often forms dense patches in these environments.
Optimal Conditions for Growth
Sweetgrass prefers rich, moist, well-drained soils, though it adapts to various types like sandy or clay if consistent moisture is available. An ideal soil pH is between 6.0 and 8.0. Incorporating organic matter, such as compost, enhances growth.
Sweetgrass thrives in full sun to partial shade; at least six hours of direct sunlight promotes vigorous growth. While it tolerates brief dry periods once established, consistent moisture is beneficial, requiring the soil to remain damp but not waterlogged. Sweetgrass is cold-tolerant, growing well in USDA zones 3 to 9, withstanding temperatures as low as -25°C (-13°F) during winter dormancy. The optimal growing temperature range is 18°C to 27°C (65°F to 80°F).
Growing Sweetgrass at Home
To cultivate sweetgrass, prepare the planting site by removing weeds and loosening the soil. Amend the soil with compost or other organic matter. While sweetgrass can be grown from seed, propagation through rhizome division is more successful due to low seed germination rates.
When dividing rhizomes, plant sections in spring or late fall, ensuring each piece has some rhizome intact. Plant them 1 to 3 feet apart for adequate space. Cutting leaves to 3-4 inches after transplanting encourages root development.
Consistent watering is important, especially for potted plants, to maintain moist soil. Regular weeding reduces competition, and organic fertilizers support healthy growth. Harvest sweetgrass in late summer by cutting leaves close to the base, leaving 1-2 inches of stem, and avoiding pulling roots. Due to its vigorous spreading habit via rhizomes, containing sweetgrass in raised beds or pots is beneficial.