By Steve Haines
Hierochloe odorata (commonly known as sweet grass, manna grass, Mary’s grass or vanilla grass, and as holy grass in the UK, Bison grass e.g. by Polish vodka producers) is an aromatic herb native to northern Eurasia and North America.
It is a sacred grass of the indigenous peoples of Canada and the United States. It is used as a smudge, in herbal medicine and in the production of distilled beverages (e.g., Żubrówka, Wisent). The name Hierochloe odorata is from the Greek and Latin. Hierochloe means “holy grass” and odorata means “fragrant”.
Propagation is easiest by cutting out plugs from established plants. Grown in sun or partial shade, they do not like drought. It will spread and can take over.
The plant is harvested by cutting grass in early to late summer at the desired length. Hierochloe odorata harvested after the first frost has little or no scent and is less desirable for basketry. Basket weavers sun-dry cut sweet grass until it is dry and brittle. The brittle form of sweet grass must be soaked in warm water until it becomes pliable. The pliable grass is typically braided into thick threads and then re-dried for use.
Everywhere it grows it is prized. The thing that makes sweet grass sweet is coumarin, a naturally occurring aromachemical that in its pure form has a scent somewhere between vanilla and warm hay. As the grass dries, the scent of coumarin becomes more pronounced.
Holy grass was strewn before church doors on saints’ days in northern Europe, presumably because of the sweet smell that arose when it was trodden on. It was used in France to flavor candy, tobacco, soft drinks, and perfumes. In Europe, the species Hierochloe alpina is frequently substituted or used interchangeably. In Russia, it was used to flavor tea. It is still used in flavored vodka, the most notable example being Polish Żubrówka.
Native American traditions
Sweet grass is widely used by North American indigenous peoples from many different Nations. Among many of the Plains Indians it is considered one of the “four sacred medicines“. Though being used for many purposes, its main purpose for many tribes is to attract good spirits. It is also known as the “Hair of Mother Earth”. Sweet grass is often burned at the beginning of a prayer or ceremony to attract positive energies. It is also to be used after burning white sage. White sage is burned to clean the energy, and sweet grass again invites in positive energies and spirits.
Sweet grass can be dried and used as a tea throughout the winter. Added by itself or with other garden herbs and flowers to alcohol, a delightful schnapps or liquor can be made. Sweet grass is a natural mosquito repellent. Some research claims it more effective than Deet.
There is an excellent book on the history of sweet grass covering both indigenous wisdom and scientific knowledge titled Braiding Sweetgrass by Robin Wall Kimmerer