Sweetgrass (Hierochloe odorata)
Holy Grass, Mary’s Grass, Vanilla Grass, Buffalo Grass, Hierochloie Odorant, Hierba de la Virgen, Bluejoint, Zebrovka, Seneca Grass, Alpine Sweetgrass
About This Plant
Sweetgrass is a hardy, fragrant, rhizomatous, perennial grass that reaches a height of about 30 inches or more. It is a member of the Poaceae family. Its upright, hollow, very shiny, hairless stems are flat at maturity and up to ¼” wide. The underside of the leaves is matte and flat (not “V” shaped). The base of the leaves, just below the soil surface, is branded purple and white. Each plant usually includes three or four blades of grass with the lower branches drooping and spreading. The blades of grass curl quickly when dried in the sun whereas most other grass leaves remain flat when dried.
Sweetgrass flowers early for a grass – from May to August. It has three flowered spikelets about ¼” long arranged on a panicle up to 4” long. The two lowest florets are male and the uppermost is perfect (both female and male).
The roots of Sweetgrass are underground shoots, called rhizomes, that grow horizontally through the soil a short distance from the mother plant before sprouting through the soil surface and growing as another plant. A single plug of Sweetgrass can spread to cover a square foot of ground in a single year. The Rhizomes form a dense mat beneath the soil surface. It can be moderately invasive. The growing nature of Sweetgrass makes it useful in wetland and riparian restoration and for erosion control on moderately sloped hillsides.
Sweetgrass’s smell is pleasant and inviting. The sweet, vanilla-like fragrance is an identifying characteristic. The fragrance becomes stronger as the plant dries and is released when moistened or in smoke if the plant is burned. The scent comes from the plant’s coumarin content. Coumarin is a natural anticoagulant, which causes the plant to be potentially toxic and able to cause liver injury and hemorrhages. Fortunately, the coumarin also gives the plant a bitter taste which acts as a deterrent to grazing animals that might be tempted to eat it. There are no know dangers associated with the ceremonial use of the herb as an incense.
Sweetgrass is a wetland plant, residing on riverbanks, moist meadows, and places along the coast. It grows wild in wet meadows, low prairies, the edges of marshes and bogs, lakeshores, and in cool mountain canyons. Sweetgrass has a circumboreal distribution, meaning the species is found in the northern areas of Europe, Asia, and North America. It is common above 40 degrees northern latitude. It commonly grows among other grasses and shrubs and is seldom found in pure stands. The species is subject to over-collecting. Wild populations are declining due to loss of wetland habitat and overharvesting for both personal and commercial use.
In Europe, Sweetgrass has been used to flavor tobacco, sweets, and alcoholic beverages like the Polish vodka Zubrowka. Its smoke is used as an insect deterrent. Decoctions of the plant are used as a body wash. It has also been used extensively to weave baskets and mats that retain the sweet scent for several years. Sweetgrass was used in Europe as a strewing herb, placed on the floors in front of church doors on Saints’ days.
Sweetgrass has been used extensively by Native American tribes for ceremonial purposes. It is used in prayer, smudging and purifying ceremonies by many different tribes and is considered a sacred plant. It is usually braided, dried, and burned. The Sweetgrass braids smolder and don’t produce an open flame when burned. It is believed that when burned, prayers, thoughts, and wishes rise with the smoke to Creator who will here them. It is also considered a medicine that honors the elders, representative of the sacred hair of Mother Earth and the sweet aroma that reminds people of gentleness, love, and kindness. A gift of Sweet Grass is considered an honor.
Sweetgrass seeds do not store well and even in nature, germination rates are low at about 25-30%. Purchased seeds often come with a guarantee of only 10% germination. If directly planting outside, the seeds can be planted in rows of about 25 seeds per linear foot or broadcast at 50 seeds per square foot. This would optimally result in 6 plants per row or 13 plants per square foot. Planting depth should not exceed ¼ inch. Tamp down lightly. The tiny seeds can easily be washed away, so follow planting immediately with a light watering. Keep moist and seeds should germinate in about 10-14 days.
Once you have Sweetgrass established, division is the best way to obtain more plants. Sweetgrass spreads in clumps with rhizomes. These side shoots can be separated from the mother plant once they have formed new roots. It is best to do this in the Fall or Winter when plants are dormant. This is after the time the seeds have matured and the leaves are dry and brown. To protect the mother plant, remove the side shoots and leave the central clump together. Make sure each plug contains a rhizome or rhizome bud. These side shoots can be transplanted into wide, shallow, pots and covered in potting soil. The pots should be kept in a shaded area for several weeks until new roots develop. Once plants are well established, they can be transplanted into the garden spaced about one foot apart.
Sweetgrass should be spaced about one foot apart. It will fill in and form a solid stand within one to two years.
Growing Sweetgrass is not difficult once you have managed to propagate it. It prefers rich, moist, slightly sandy soil in full sun. It will tolerate partial shade as well. Weeding is important as the Sweetgrass establishes itself to lessen competition. The soil should be kept very wet to moist. The plants may need to be protected from herbivores such as rabbits or gophers. Dogs love to roll around in Sweetgrass. Protect it accordingly.
It is important to cut Sweetgrass when harvesting and not pull it up by the roots. You want to ensure its survival and that it fulfills its role of holding the soil in place. Sweetgrass is traditionally harvested in late June or early July. Sweetgrass loses its scent once exposed to frost.
Sweetgrass seed is often infertile and has a very low germination rate. Sowing fresh seed is optimal if propagating it by seed. Sweetgrass seeds ripen over an extended period of time so you’ll have to hand-select mature seeds from your plants. As seeds mature and turn completely brown, cut the stalk and then strip it of seeds over the soil of a seed tray. Spread the seeds evenly, gently tamp into place, and water with care. Germination will begin in one to two weeks. Allow the seeds to grow a few inches before transplanting into pots.
- Cosmetics such as hair washes
- Basket making
- Culinary infusions
- Riparian restoration and erosion control
Sweetgrass’s culinary applications is somewhat limited, but it can be distilled into beverages. It is sometimes used as a flavoring agent in alcohol, especially vodka.
In addition to ceremonial purposes, Sweetgrass has a long tradition of being used medicinally. Used as a tea, it is considered helpful in treating colds and flu as well as fever and sore throat. It is used as an eyewash for eye infections. It also was used historically for venereal diseases. The smoke from Sweetgrass was also inhaled to treat colds.
Sweetgrass was also used as a tea by women after giving birth. It was said to help prevent bleeding and to help expel the placenta. It also was used to treat women who had suffered a miscarriage. Women burned braids of Sweetgrass after their moon time for cleansing.
The steams were soaked in water to create a wash for treating windburn and chapping. Decoctions were also used as a hair and body wash.
Sweetgrass is native to the cooler regions of North America and Europe above 40 degrees north latitude.