It won't grow if you don't feed it. Or, it will grow very slowly. Candy canes/trumpets are one of the corals that seem to benefit the most from feedings. It really makes a difference with them. You can feed it meaty foods, like frozen mysis, krill or brine. Use a turkey baster to gently blow the food on them when their tentacles are out. I have 6 different types of candy canes in my tank -- I feed them often, and they grow one or two new heads every month.