200 STINGING NETTLE (Bull Nettle / Tread Softly) Urtica Dioica Flower Seeds BLOOM TIME: All Summer HARDINESS ZONE: 2 - 10 PLANT HEIGHT: 36 - 48" . . . PLANT SPACING: 15 - 18" LIGHT REQUIREMENTS: Sun . . . SOIL / WATER: Average - Dry The Stinging Nettle is covered in small stinging hairs that can cause itching and pain. Some people can have an allergic reaction to them. That having been said, they do make a great protective plant! Grow them underneath windows or anywhere you want to make sure intruders dont go.