Aug-Oct, H 18-36", W 18-48", Z 3-9 Minnesota-bred Mammoth™ is extra-hardy. True perennials that come back year after year, they can survive -30°F. Requires no pinching, pruning or deadheading. By their second or third year, they can reach 4' across, making a tremendous impact in the landscape. PP
Growing Zone: 3 to 9
Light Requirements: Full Sun
Height: 18-36"