This section is from "The Horticulturist, And Journal Of Rural Art And Rural Taste", by P. Barry, A. J. Downing, J. Jay Smith, Peter B. Mead, F. W. Woodward, Henry T. Williams. Also available from Amazon: Horticulturist and Journal of Rural Art and Rural Taste.
There is hardly a more beautiful or useful plant in cultivation than this Clerodendron; for, under good management, its large clusters of brilliant scarlet blossoms are produced in great profusion, and they last a long time in perfection. Unfortunately it can never be everybody's plant, for it cannot be grown with advantage except where it ean be furnished with plenty of heat and moisture during its growing season. Where there is convenience, however, it is well worth attention, and will be found to amply repay any amount of trouble which may be bestowed on it.
It may be readily propagated by cuttings made of short-jointed young shoots, selected in a rather firm state, inserted in sandy, peaty soil, covered with a bell glass, and afforded a brisk bottom heat. It may also be increased by grafting it on any of the stronger growing varieties; but, although this plan was at one time much recommended, it has now, I believe, fallen into disrepute, the plant having been found to do quite as well on its own roots. The young plants should be potted singly in small pots, as soon as they are sufficiently rooted to bear handling, and replaced in bottom heat, in a moist, warm situation. When well established, shift into other pots, two sizes larger, and keep them as near the glass as is convenient, in order to indues the production of strong, short-jointed wood. And during the growing season, continue to afford them a brisk bottom heat of 85° or 90°, with a warm, moist atmosphere, and all the light possible, merely guarding them from the direct rays of the sun on the forenoons of bright, warm days. Do not early in the season, to as to get strong, well-furnished plants by autumn, when they should be removed to a drier atmosphere, gradually withholding water from the soil, wilh a view to get the wood well ripened.
And I may observe that upon this, and the plant being allowed a period of rest, future eoeeeae greatly depend; for unlets the wood it properly ripened, and the natural season of lost afforded, there will be no potability of getting them to break strongly or grow vig» oroutly; bat if these partioulare have been properly attended to, they will grow equally well whether started in Jane or March, and form epleadid plante for bloomiog in a warm bouse during winter. IŁ however, your young plants are intended for bloomiog in summer, water should be gradually withheld towards the middle of October, and they may be removed to their winter quarters by the middle of November, which may be a corner of the stove, or to any dry situation where the temperature may average from 50 to55°, and no water should be given to the soil during the resting season. About March turn them out of their pots and shake away at much 0r the soil as can be done without injuring the stronger roots, and re-pot in not over-large pots, using good fresh turfy loam, rich fibry peat* and leaf soil in about equal proportions, well intermixed with plenty of sharp sand to secure rapid drainage, cutting the shoots well back to strong prominent eyes, After potting, plunge in a sharp bottom beat, and maintain a moist atmosphere by frequent syringing, but carefully avoid overwalering the soil, until the plants fairly start into growth.
The shoots may be loosely trained to stakes until the plants can be shifted into their flowering pots, when light wire trellises may be applied, so as to enable them to be kept neatly and regularly tied There is no danger of overpotting a plant like this, for with good management plenty of light and the command of heat and moisture, it will fill a 20-inch pot and form an immense specimen in the course of a few months, or it will bloom nicely in a 12-inch pot, forming a handsome moderate sized plant Therefore, the size of the flowering pots may be regulated by circumstances, the only difference being that the plante will bloom earlier and their beauty will be shorter lived jn small pots, and vice overs.. If a large shift is given, however, be very .careful not to give too much water to the soil, until the roots reach the sides of the pot, and when this is the case a liberal supply of clear manure water should be administered. Keep the shoots regularly trained to the trellis, and continue to keep up a brisk bottom beat, with a warm, humid atmosphere, until they are fairly in bloom, when they may be gradually prepared for removal to the show-house; and if this is done carefully, and they are afforded a close corner not exposed to draughts, tbey will continue to unfold their brilliant flowers for a very long period.
By taking care to get the wood well ripened, affording the plants a period of rest, and disrooting, Ac, as recommened above, the specimens will last for any number of years. - Alpha in Gevd. ovron.