Outsidepride Sweet Woodruff Ground Cover Plant Seed - 200 Seeds Sweet wooruff is a perennial herb grown in USDA Zones 4 - 8. Also known as galium oderatum or asperula, this perennial only grows to 8 inches tall and gets a white flower. Often used as a ground cover, sweet woodruff herb plants have whorled leaves and small vanilla-scented white flowers in spring. Historically, it was grown for an aromatic plant that was used as an air freshener and placed in linen closets. Sow 4 to 5 of these non gmo, heirloom seeds per garden plant you desire.