Colocasias are very heavy feeders, so if your plant isn't growing enough, you either need more heat or more nitrogen. All of the colocasias we offer are hardy here in Zone 7b. Although suitable for soggy conditions, the cold-hardiness of colocasia is increased in soil that is not soggy during the winter. Where they remain in the ground over winter, they will be quite late to re-emerge in late spring or early summer, unless they are covered with 3-6 of mulch in early fall. North of Zone 8, it is essential that they are not planted after late August to ensure best winter hardiness. In parts of the country, a few of the newer cultivars of elephant ears do not form large tubers, and if dug in winter, cannot be stored dry due to a lack of adequate food reserves. These are best overwintered in containers in a cool basement or garage that remains above freezing. They also will not take a notion to grow until the summer temperatures escalate.