Uses: Medicinal/Aromatic Duration: Perennial (hardy in zones 3-9)
Traditional Amerindian ceremonial grass used in peace and healing rituals. Vanilla-like scent. Very easy to grow; prefers moist soil and full or partial sun.
Note: Sweetgrass seeds typically have a low germination rate, around 5-10%. This is due to a biological limitation in sweetgrass flowers to produce viable seeds. Fortunately, a single seedling can produce hundreds of plants because the roots produce many rhizomes which develop into new plants.
Restoration: Sweetgrass is a useful plant for wetland and riparian restoration and mitigation and spring protection/renovation. Sweetgrass has potential for conservation use for erosion control on moderately sloping, hillside seeps. Seeps are sometimes erosive because the soil stays liquid and the saturated conditions inhibit the growth of many plants. The sod-forming and moisture tolerant characteristics of sweetgrass will stabilize the seep (Ivan Dozier pers. comm. 1999
Propagation from Cuttings: Sweetgrass can be propagated easily from container or bare rootstock, as it produces many rhizomes. It can also be propagated from seed. However, in nature, sweetgrass is a sporadic seed producer, and germination rates are fairly low (25-30%), so propagation from seed is more difficult than from cuttings or division of plants.
Handling and care requires commitment and attention to detail to maximize survival. Initially, the plants should remain in the pots for an additional 2-3 weeks after you receive them, and watering must occur every day while in the pots. This is because of the possibility of lingering transplant shock and because the soil in the pots dries out fairly quickly. The plants will continue to grow and thrive in the original containers for quite a period of time while site location and preparation efforts are finalized.
Pick the sites where sweetgrass is to be transplanted carefully, and prepare the site properly before planting. It is advisable to keep the immediate planting area clear of competing vegetation, which may simply mean hand weeding around individual plants, or a mechanical means may be required. Sweetgrass grows in wetter areas in its natural habitat, and during the establishment period irrigation is likely to be required. Soil should be kept very wet to moist.
After the plants have established and grown to a minimum height of 4 to 6 inches (to avoid damaging small seedlings), routinely weed and remove unwanted vegetation. This will reduce competition for light, nutrients, and water, and encourage vigorous plant growth and development. Sweetgrass prefers a moist environment, so regularly water the site. The rhizomes (underground, horizontal stems) develop early and will emerge during the first growing season. The grass will continue to spread if left unattended. The leaves will reach a length of approximately 12-15 inches and can be harvested once or twice a year. The foliage is very relaxed and it will be necessary to carefully lift the leaves and cut the stems close to the ground (leave 1 to 2 inches of plant stem). The actual number of harvests per year will depend on climatic conditions, seasonal timing, and the traditional environmental knowledge of the particular indigenous group tending the grass. Plan the final harvest (late summer in northern climes) so that there will be adequate time for the plants to prepare for the onset of cold temperatures and winter conditions. If this natural hardening-off process does not occur, it will eventually have a detrimental effect on the long-term persistent and survival of the stand. Fertilizing is not recommended in the first year of establishment, as weeds would reap the most benefit during that time. The use of a balanced, all-around, granular fertilizer is recommended after the first year.
Site Preparation: The site should be prepared well in advance of planting, either late in the fall or very early in the spring. Preparation includes the following: removal of all weeds; rototilling or hand-digging so that the soil is loose and friable; raking or smoothing to a level, clump-free grade; packing or rolling to firm the surface (afterwards, only light foot imprints should be visible when walked across); and moistening the soil evenly to a depth of 2 to 3 inches (or when surface puddling is evident) with a sprinkler or hand-held spray nozzle.
Seeding: Sweetgrass is a cool-season species that requires a period of cold temperatures before it will germinate from seed. Late fall, late winter, or early spring is the best time to plant the sweetgrass seed. At the time of seeding, the soil should be moistened to a depth of 1 inch. The seed should be fully ripened (very firm when squeezed between fingernails or when clipped with a fingernail clipper) and free of debris. Sweetgrass seed is very small at approximately 1.1 million seeds per pound. Depending on the amount of seed available and the plant density desired, the seed can be dribbled in rows at a rate of up to 25 seeds per linear foot, or broadcast at 50 seeds per square foot. This may optimally result in 6 plants per row and/or 13 plants per square foot (seed germination tests have averaged 25-30%). Planting depth should not exceed 0.25 to 0.5 inches. It is very important after seed placement that the area be re-rolled or packed to ensure satisfactory seed-to-soil contact. The tiny seed can be easily washed away, so follow planting immediately with a light watering. Keep the area moist until seedling emergence, in about 10-14 days. In soils (clayey) that are prone to crusting, subsequent periodic, short-duration watering may be necessary