Indestructible. Invasive. Resistance is futile. Where once there were two plants barely 2 feet high, now there exists a large colony of cannas, extending its dominion into my front flower bed. The tubers photographed this past weekend captures the aggressive nature of this plant; the root system covers about a 2′ by 3′ patch of bed, and there are no signs that it is letting up. I began dividing the roots and planting them in pots to grow babies for the new year.