Toxicity and Risks of Sweet Woodruff Galium odoratum is considered to be toxic to both pets and people, especially in cases when large amounts are ingested. The toxicity of this plant is due to its concentration of coumarin, present throughout all parts of the plant.

Aerial parts and flowering tops are used as a treatment for nervous agitation, jaundice, hemorrhoids, circulation and venous disorders traditionally and the crushed leaves have been used topically to reduce swelling and to accelerate wound healing (3,4).

There are several native species of Galium, but G. odoratum is an Old World species, hardy in USDA Zones 4 to 8. Sweet woodruff prefers moist, rich soil in partial to full shade but will tolerate dry and less-than-optimal soils.

The tubular, star-shaped flowers are borne in small terminal inflorescences held above the foliage. The flower buds (L) and open flowers (C and R) of Galium odorata. It spreads readily in ideal conditions, to the point of being considered invasive.