Answer: Japanese Sweet Coltsfoot (Petasites japonicus) is hardy only in USDA zones 5-9. You'll need to dig yours up and store it in an unheated garage for the winter months. This plant grows in part shade to part sun and reaches 2-3' tall and 2-5' wide when given abundant water during the growing season. Try planting it in a slightly warmer site next year and it should grow and bloom for you.
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