Last fall I planted my Chrysanthemums in large ceramic pots. The name of them is "Helen" - They were really beautiful. Anyway, they stayed in the containers outside all winter. Just this past week I noticed new growth coming up at the base, but the old dead branches are still there. When should I cut those off? Looks to me like they survived the winter in the containers. Can someone please tell me what I can do to bring them back nicely again? Ideas? Thank you.