Start tubers in a cold frame or greenhouse during March or April. Press tubers into boxes of damp peat, hollow side uppermost, planting just under the surface. When leafy shoots appear, transplant separately into pots of soil-less compost. Plant out in June after the danger of frost has passed. Pendula varieties are excellent for hanging baskets. In October lift tubers, remove stems after foliage has died and store tubers in dry peat, in a frost-free place.