This section is from the book "The Florist And Garden Miscellany". Also see: All New Square Foot Gardening: Grow More in Less Space!.
This brilliant member of a beautiful genus was introduced into this country from Mexico some thirty years ago. It is well known, and frequently met with, but more commonly in a neglected state, than receiving that attention which its easy culture, its free flowering at a season when flowers are generally scarce, and its dazzling scarlet colour demand for it. It has occasionally been recommended for out-door flowering; but for this purpose I have not found it worth its room. My attention was first directed to it as a valuable winter plant, from a paper by Mr. Wood, which appeared in the Gardeners' Chronicle; but, instead of growing it in winter, as Mr. Wood directed, I imagined that the better plan would be to grow it during summer and autumn, and to try the effect of retarding the blooming; this plan I have found to answer perfectly; and, in my estimation, it is to the conservatory or greenhouse, during the dull months of winter, what Scarlet Geraniums are to the parterre in summer - the most attractive of the whole; and I have no hesitation in stating, that attention could not be turned to any neglected plant which would better repay the trouble required in its cultivation than Salvia splendens.
I am much pleased with the cheerful effect of its brilliant flower-spikes; they serve, in an eminent degree, to brighten up the dulness which too commonly prevails at the period of the year in which it blooms. Its easy culture points it out as a plant well suited to the circumstances of the amateur; for, although it grows to a size far beyond the conveniency of the amateur of small means when treated as gardeners do who admire it, and who can command room for its full development, yet it may be treated so as to cause it to adapt its size to a very limited space. For this purpose I have found the following treatment suitable.
About the middle of March let cuttings of rather firm wood be obtained, and treated like those of the Verbena. If favoured with a gentle bottom-heat, they will soon emit roots, and will commence growing vigorously; they may be stopped once or twice previous to being potted off, as they are not particular about losing a few roots. Pot into 5-inch pots, and place the plants somewhere near the glass, where they can be kept close and moist. Here they will soon grow rapidly, and must be frequently stopped, so as to make bushy plants. I never allow them to make more than one new joint, until I have obtained as many shoots as I think necessary for the formation of the future bush. As soon as the plants are well established in their pots, shift them into a size larger; 9-inch pots will be sufficient, if large plants are not desired. Towards the end of May, or as soon after that period as your dread of frosts and cold nights has left you, prepare the plants for a place out of doors; if they can be plunged in a sheltered border, exposed to the sun, they will require little further attention except staking, and turning round the pots, to prevent their roots from getting into the soil in which they are plunged.
Stopping must, however, be attended to, in order to make dwarf, handsome plants; but this must not be practised after the middle of August, except flowering can be assisted by placing the plants in a close house. About the middle or latter end of September, remove them to the warm end of a greenhouse or pit, in which they will soon be clothed in the richest scarlet, and will prove well worth the little trouble they have cost you. If they are supplied with manure-water during their flowering season, the latter will be considerably prolonged.
I have said nothing about securing a succession of bloom; nevertheless this ought to be attended to. For this purpose it is simply necessary to select a portion of the plants, and to pinch out the ends of the shoots just as they are shewing flower, which, with the treatment I have recommended, will be early in September. Another portion may be stopped a month, or even two, later; but this must depend upon the treatment which it will then be possible to give them. By means of dividing my plants into three lots, I secure a succession of bloom from October to March; but my second and third lots of plants have the assistance of a close greenhouse during the summer and autumn; or even something warmer, if it is found necessary to bring them into flower at a certain time. The amateur will find a season's practice the best guide in this part of his management. When they are done flowering, save one plant, and keep it without water until it shews symptoms of dryness; it may then be cut back, and kept in any spare corner until the time for making cuttings draws near. If it can be placed in a rather warm atmosphere, it will soon furnish abundance of young wood, which must be treated as stated above.
In a comfortable place under glass, and with plenty of pot-room, etc, this plant attains the size of five feet high, and as much through; and in November is covered with scarlet from the edge of the pot upwards; but, of course, such large plants would not suit an amateur.
This plant would doubtless produce its flowers in the window of comfortable sitting-room; but for this purpose I do not recommend it, as it is apt to become drawn in the absence of direct solar light, have said nothing about soil; but it will be found not to be particular in this respect. I use sandy loam and thoroughly decomposed cow-dung, in about equal portions; but if small plants are wanted, use light, poor soil.
Attington, Oct. 15. Henry Greton.