This guide was written by my friend, Helena Weisner, She has the expertise of growing Cyclamen for many, many years in the U.K. It is reprinted with her blessing.
Cyclamen hederifolium is the hardiest of the cyclamen genus and will grow well in even the toughest of conditions. It is usually in flower from August to November and has attractive variable leaves which provide added interest until May. The flowers appear before the leaves and vary in colour from mauve to pale pink. There is also a white form. In the wild, C. hederifolium occurs from the south of France to Turkey and on many of the Mediterranean islands. The tubers are very long-lived and naturalise well, producing many flowers on older tubers.
Cyclamen coum is also extremely hardy and will survive the severest weather. This species flowers in January to March and provides colour in the garden when little else is in flower. In the wild, it is widely distributed from Bulgaria, Turkey, Russia, Iran through to Israel. It is a species with wide variation. The leaves are kidney shaped, dark green either plain or with silver markings. The flowers are pink, white or magenta coloured.
Height 4 in, planting distance 4-6 in. The tubers we supply have been dug up just before dispatch with the soil removed. They should be planted as soon as possible after arrival. They like light dappled shade, shelter from strong winds and well-drained soil. For growing outside, the shelter of trees and shrubs is ideal. Adding course grit, leaf-mould and peat to the soil will provide suitable growing conditions. They will tolerate reasonably acid or alkaline soil. When planting, barely cover the tuber with soil but add 1 in of leaf mould annually after the flowers have finished and the leaves have died.
Cyclamen are self-pollinating and set seed easily. The flower stalks curl into a spiral drawing the seed capsule down onto the top of the tuber. When the ripe seed capsule starts to split, the seed can be harvested and sown, or can be left on the plant for distribution by insects and birds. Seed can be sown in John Innes seed compost or in a mixture of one part leaf mould or peat, one part soil plus a little bone meal and one part coarse grit. The seed compost should be kept cool and moist until the seedlings emerge, and they should be encouraged to grow on as long as possible by keeping them moist, cool and well-shaded in late spring and summer. Prick off the seedlings into 3 in pots of compost (it can be the same as the seed compost mix described above or John Innes No 1) and overwinter in a cold frame. Plant out in their flowering positions in May or late summer.