This section is from the book "The Gardener V1", by William Thomson. Also available from Amazon: The New Organic Grower: A Master's Manual of Tools and Techniques for the Home and Market Gardener.
There is perhaps no more attractive group in the whole range of Alpine plants than that comprised in this genus. They are all neat and dwarf in habit; all have foliage of pretty form; and the flowers, in every case beautiful, are in some exquisitely so. They are mostly spring-blooming plants, so early, indeed, that in our fitful climate their beauties are rarely enjoyed out of doors; but cultivated in pots they are well adapted for the decoration of rooms, the conservatory, or greenfrouse; and for choice cut flowers, the fine colours, peculiar and beautiful form, and, in the case of some sorts, the delicate fragrance they possess, render them charming. Their culture is simple enough when their nature and requirements are understood and attended to. With the exception of Cyclamen persicum and its hybrids and varieties, and perhaps also Cyclamen repandum, the remaining species may be considered hardy Alpine plants. For the most part, the species inhabit high cold regions on the great mountains of southern Europe, and their constitution is consequently adapted to resist the greatest cold they will be exposed to in our climate; but when winter is gone, and we are looking forward with expectation for the unfolding of their beauties, along with the lengthening days of March and April, the late frosts and battering rains so common in these months bring disaster to Cyclamen flowers, as they do to the flowers of many more important things.
Something may be done to protect them, with hoods or extinguishers of frigi domo, so made as to be easily slipped over and fastened upon stakes permanently fixed around the plants, in anticipation of inclement weather; but it is troublesome and unsatisfactory, inasmuch as we are often taken at unawares by the sudden changes experienced in the spring months. It is necessary, therefore, if we would fully enjoy the beauty of the early-flowering Cyclamens, to provide them with indoor accommodation of some sort. It is one of the recommendations of these plants that they do not take up much room in winter; many may be stored in small space. A cold frame in which the pots may be plunged in coal-ashes is the most suitable place for them; but in the absence of that, they may be stored under the stage of a cool greenhouse, or in a vinery or peach-house, in which, if not provided with heating apparatus, the roots would require to be protected by some means in severe weather. Hand-glasses and cloches are fit enough also for wintering a few plants, and they may even be successfully flowered in such; but nothing could be better for the cultivation of these and kindred plants all the year round than those cheap ground vineries; they are specially commendable to amateurs for such purposes.
The only successful means of propagating these plants is by seeds. Division of the root-stock has been recommended, and may be practised, but the result is bad; solid corms, like those of Cyclamen, when divided, never produce vigorous healthy plants. The seeds, if early ripened, may, in the southern parts of the country, be sown at once thinly in shallow pans, and placed on a spent hotbed, cold frame, or on the shelf of a greenhouse near the glass, attending properly to watering, and, after the plants appear, to shading from direct sunlight. In the north, however, where the season is short and the ripening of the seeds later, it is better to defer sowing till February or March. About that time a mild hotbed should be in readiness to receive them, in which the temperature should range not higher than 60°, nor lower than 50°, but be kept pretty steadily between the two. The compost in which to sow is of some importance, as the plants will remain in it undisturbed for the next seven or eight months; and as a vigorous infancy lays the foundation for a successful maturity, a little pains at this first stage will prevent after-disappointment. Equal parts fibrous loam and peat, and about a fourth part of two or three year old sheep or cow dung, with a very liberal allowance of sharp sand, form a compost in which Cyclamens delight.
The whole must be carefully mixed, and for the seed-pans should be passed through a 3/4-inch sieve once or twice, and a small portion for the purpose of covering should be sifted finer; but for established plants, the compost need not be sifted, but merely rubbed, and mixed carefully with the hands. Sow, as before said, thinly in shallow well-drained pans, cover lightly, but completely, and place in the hot-bed. Till the plants appear the temperature of the frame is best kept moderately close, and shading should be used to prevent sudden drying of the surface of the soil by the sun; but when the plants are fairly visible more air will be necessary in order to induce vigorous growth: sudden fluctuations of temperature must, however, be guarded against by all means till the weather becomes less variable and the plants acquire greater strength. From first to last, during the growing period, shade from bright direct sunshine is of the utmost importance to the wellbeing of Cyclamens, whether seedling or established; and careful attention to this item, in the treatment of seedlings especially, cannot be too strongly inculcated. Up till the end of August everything should be done to stimulate rapid and vigorous growth.
Admit morning and afternoon sun, and, according to the condition of the external temperature, a free allowance of air early in the day, but shut up with a little extra warmth in the afternoon, reopening the lights again a little at night throughout the three summer months; and attend carefully to watering and cleanliness. By the last week in August, the plants under this treatment will have made con siderable progress, and attention must now be directed to the maturing of growth before finally setting them to rest. Cautiously inure them to a fuller exposure to light and air, till the lights may be wholly dispensed with; and be more sparing in the supply of water, but never allow the leaves to flas;. The first week in October should find them well matured, and they may then be turned out of the seed-pans, saving the fibres from unnecessary injury in the process, and potted singly into pots suited to the size of the corms, bearing in mind that the first shift should be a small one, and that the pots be well drained.