5 Cinnamon Fern Rhizome/Root (Osmundastrum Cinnamomeum). You are buying 5 cinnamon fern healthy mature roots. Dramatic architectural form and color make a striking focal point near the edge of water features. Long fronds are blue green in summer with new growth covered in white hairs fertile fronds are a contrasting cinnamon brown. Reach heights of 4' tall and 3' wide. Make excellent boarder or mass planting in vary wet areas, water gardens or woodland gardens. Hardy in zones 4-8. Planting instructions included with every order.