A Guide Large-flowered Hybrids Flower

The begonias belonging are the most easily available commercially and the most widely used. They can be obtained in a wide range of colours including dark scarlet, salmon, pink, white, and yellow. All these begonias which are generally propagated from cuttings are mostly cultivated as pot plants, although sometimes they are planted in beds. The very large-flowered forms are, however, not recommended for outdoor cultivation as they can be easily damaged by bad weather and require careful tying and staking in view of the weight and fragility of both the blooms and the brittle, fleshy stems. Among the most widely cultivated, some of the best are:

Small-flowered Hybrids

These hybrids originated from crosses between Begonia davisii, Begonia octopetala, and Begonia pearcei. They have a maximum height of and the flowers do not exceed  in diameter, but they are very prolific. They are also more tolerant of direct sunshine than the larger-flowered types. The plants are best suited for cultivation in beds and offer an excellent alternative to Begonia semperflorens. In my opinion, they are worthy of wider cultivation and preferable to B. semperflorens because of their greater range of colours and for their more attractive foliage, which has a more natural aspect and is less artificial looking than that of B. semperflorens. They are also excellent for cultivating in boxes or other receptacles on terraces and balconies, for shady borders, or as foundation plantings against a house. The most widely used are:

Medium-sized Flowers

These hybrids are the results of crosses made between the large- flowered hybrid begonias and the small-flowered ones. After experimenting with all the different types, I must confess that these medium- flowered plants gave me the least satisfactory results. They appear to have all the defects of mongrels without any of the good points of either parent. The plants reach a height, with flowers in diameter. Those most widely planted are:

Bajazzo, orange-red; Brautjungfer, silver-pink; Heimat, salmon-orange; Mandarin, scarlet red-orange; Tasso, blood-red with bronze-green foliage

Pendulous Forms

These plants bear smaller leaves and flowers on pendulous branches. They are particularly suited for cultivating in hanging baskets, or in pots placed on shelves or suspended from brackets. When the climate permits, some lovely effects can be obtained by hanging baskets of these begonias from trees. They are also useful for arbours and terraces. The various types have the same range of colours as the other classes.

Plants of the tuberhybrida group are reasonably robust, vigorous subjects. They need a rich soil, semi-shade, and a cool, fresh atmosphere. In the north, in mountainous districts, and in seaside localities they are more tolerant of sun. They are generally cultivated outdoors in boxes, tubs, pots, or other receptacles. Before planting, it is a wise precaution to give the tubers a dusting with one of the fungicides available on the market. The grower who does not possess a greenhouse can start his tubers indoors in February–March, and the ideal growing temperature. Otherwise tubers can be started into growth outdoors. But, since this should be done before the end of April—and as the plants are tender—this method may prove impractical in cool districts. In either case, the tubers should be placed on a layer of moist peat or moss and set in a place which is sheltered and not too light, and kept moist. When they have produced growths long, the tubers can be covered with soil; but do not cover them until this active growth has been produced, otherwise there is a risk of the tubers rotting. When the new shoots produce leaves, the tubers can be potted individually or placed in the receptacles or positions where they are to bloom, using a soil mixture composed of equal parts of peat and leafsoil plus a sprinkling of sand and finely ground charcoal. When flowering has finished and before the weather becomes cold, watering should be progressively reduced and finally suspended so that the tubers will reabsorb all the moisture and nourishment contained in the leaves and stems. When all vegetation has died down, the tubers can be removed from the soil, dusted again with fungicide, placed in dry sand or peat, and stored in a dark, dry place at a temperature.

Specialists who raise tuberous begonias from seed sow it in January in a mixture composed of equal parts of peat and leafsoil plus a sprinkling of sand. The seed must not be covered with soil, and should be kept at a temperature of  Seedlings will be ready 5 weeks after sowing for pricking out into a similar compost; they should be kept at a temperature. until mid-April. They can then be transplanted into nursery beds in heated frames. After 2 weeks the young plants can be replanted again, but this time into outdoor nursery beds, in a similar compost containing a higher percentage of peat. Plant at a distance, apart so that the seedlings can develop and produce good-sized tubers.

A less complicated method is to propagate from cuttings taken when the tubers start their growth in February-March and when the young shoots are about high. However, take only one cutting from each tuber so as not to weaken it excessively. These cuttings should be inserted in sand in a warm closed greenhouse and kept shaded and moist until roots have been formed, when they can be individually potted.