ON THE CULTURE OF TUBEROUS BEGONIAS.

Globe, Volume XXIII, Issue 2143, 7 January 1881, Page 3

ON THE CULTURE OF TUBEROUS BEGONIAS.

The details of the culture of this popular class of greenhouse plants should rightly begin with their treatment when they are going to rest. The first point to be observed is to gradually withhold water from the roots as soon as the stems and leaves show signs of decay. Begonias, unlike many other plants which are tuberous or bulbous, do not show these signs of decay at the upper extremities of the shoots or stems first, but at the lower extremities. Very often, indeed, extra vigorous plants damp or “ fog ” off close to the crown of the tuber, while the upper parts of tho stem and branches, and oven the leaves, show bat very little symptoms of distress. But as soon as these indications of going to rest are observed, the supply of water should be gradually reduced. The plants should also bo placed in a sunny and airy eosit-ion. One out of doors, where they may 30 sheltered from strong wind, will suit them better than tho more confined atmosphere of a house or frame. As the stems die off let them be cut away, but none should be cut which are not quite dead. When the stems are all cut away tho pots should be put on their sides under the stage of a cold greenhouse, where they will not be exposed to any heat above 35 to 39 degs., but whore they will not be; liable to any frost whatever. In this position they will be quite safe for the winter. They should never, however, be put away in a dust-dry condition. They rot or decay as readily in extreme dryness as in extrema wetness.

The time of starting the roots into growth should be regulated by circumstances. If they are simply intended far the decoration of the greenhouse during any period of the summer, they may be brought out of their dormant state by placing them in mild heat two or three months before the time they are desired to be at their best. By attending to this point, and bringing them in in batcheo of such a number as may be required for the purpose in view, a very long succession ct their beautiful flowers may be kept up. But if they should be wanted for the purpose, first, of yielding a number of cuttings for propagation, as in the case of scarce and desirable sorts, they must bo taken into heat early in the beginning of the year. Having determined the time the roots are to be brought into activity, let them bo taken to tho potting bench, and there turned out of their pots, and entirely freed from the old soil. Every root should be carefully examined in order to detect any rotten parts, which should be cleaned away ; and if tho rot is of a soft nature, the affected parts should be dusted with quicklime after being well cleaned. More generally, however, the rot will be found to bo of a dry sort, and the affected part will break away from that which is sound, leaving a perfectly callous surface underneath, which requires no treatment. These may be potted and put in heat at once, but the others should be allowed to lie exposed to a brisk warm air or dry heat for a day or two before being potted, so that the wounds may become quite dry and the lime crusted upon them. They may then be potted and placed with tho others in Temperature of about 55 to 60 degs. at night, if they are to be propagated by cuttings ; but if merely to be grown into decorative plants, they should be treated to 5 degs. less at night, with in either case a rise of 5 degs. during the day. We shall now follow the course of treatment required ordinarily for the production of plants for the purpose of decoration only, and leave the treatment of those intended for the purpose of propagation, along with the details of the treatment of the cuttings, for subsequent consideration. At tho first potting the roots should be put in the smallest sized pots. Very small roots, such as may be obtained from cuttings of the previous year, may bo put in 2-inoh or 3-inch pots, according to the size of the roots, and these smaller sized roots should bo just merely covered with soil. But in the case of large sized roots, the leas soil there is between them and the sides of the pot tho better; nor should these be covered with soil at all, the surface of the tuber should be just level with the soil. A little water should be given, merely a sprinkling to settle the soil about tho root; but with the exception of a light dewing over with tho syringe in the morning, that is all the moisture they should receive till they show active signs of growing, after which water must be given in proportion to tho progress of growth. The temperature should remain the same from first to last, except it bo desired to push them faster than they may be doing for any special purpose. But they are plants that should not bo pushed by heat for any considerable length of time. They delight in a light friable loam, rich in manurial matters, such as dried cow or horse dung, bone meal, and leaf mould. Tho proportion of these to the bulk of the soil depends upon tho quality of tho soil. Should it bo poor, a third of leaf mould may be added, and a fourth of dried cow or horse dung, and to every bushel of this, about a quarter of a peck of bone meal may bo given and thoroughly well mixed. A little sharp sand, if the soil is of a olose or clayey sort, will be needful to keep all open and porous. When the stems begin to grow apace, discontinue tho use of the syringe overhead, but keep the moisture of the atmosphere abundant by means of the evaporating troughs, and sprinkling the walls and passages with water several times a day. Stakes must bo applied to the stems betimes, bo as to prevent accidents. Tho plants must also receive additional pot room as soon as they appear to want. it. They should not be allowed to become pot-bound in any degree till they occupy their flowering pots, after which they may be kept up by means of liquid manure.