This section is from the book "The Gardener V2", 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.
This is one of the most useful and showy of stove spring-flowering plants, which produces its orange-yellow bells in great profusion when carefully cultivated. The plant is simple to propagate and cultivate, but is somewhat difficult to ripen into a free-flowering state, unless its requirements are thoroughly understood. Cuttings taken of it during the months of March and April, or small plants of it purchased from the nursery, and grown on; will make nice plants for furnishing next spring, and will with ordinary care develop into fine bushes the following season.
In preparing for inserting the cuttings, the pots should be washed clean, and drained by the ordinary process, and then filled with a mixture of well-decomposed leaf-mould mixed with sharp sand - say in the proportion of one-third of the latter to two-thirds of the former. It will also be advisable to leave space to the depth of an inch on the surface of the pots for a layer of pure sharp sand, which should be pressed down with the ringers and made firm, and into which the cuttings should be inserted. The cuttings should be selected from a clean healthy stock; and of course it is understood that in all cases of propagating, the materials employed should be of the same temperature as that from which the cuttings are taken, and be in good working condition, - that is, to be neither too wet nor too dry. After the cuttings are inserted, the pots should be plunged in a pit or propagating-frame with a bottom-heat of 85°. There is no objection to propagating such plants in a frame with the ordinary bedding plants, such as Verbenas, etc.; but if a moderate bottom-heat is at command in a pit heated by hot-water pipes, the latter should be preferred, as being more conducive to a steady growth than the conditions of the former, as heat fluctuates so rapidly in an ordinary dung-frame when exposed to the external conditions of an ever-varying atmosphere; but, as before remarked, much depends upom circumstances, such as season of propagating, locality, situation, etc. etc.
Assuming, however, that the cuttings have been plunged in a bottom-heat such as that recommended, they will soon form roots if the necessary conditions are observed in the way of shading, syringing, and watering.
After the young plants are sufficiently rooted they ought to be shaken in the plunging material, leaving a vacuum between the pot and the material in which it is plunged, preparatory to placing the cutting-pot upon the surface of the bed, to prevent anything like an abrupt check to growth. The same conditions of atmospheric treatment will still require to be maintained, except that the shading may be dispensed with after the cuttings have furnished themselves with roots, until the plants are ready for potting, which will be as soon as they are fit to be handled, and are large enough to be shifted into 3-inch pots. Before they are shifted, the soil for potting should be got in readiness, by having it mixed and laid up in a heated shed, or at all events in some dry place where it can be taken from and warmed to the necessary temperature a few hours before it is required for potting. The soil should be mainly friable loam, with a dash of leaf-mould and sand mixed with it. Rich soils and overpotting are to be avoided in the cultivation of these plants, especially in the northern parts of the kingdom, where light and sunshine are at a minimum.
The plants would only require all the more ripening if their treatment were such as to induce soft growth, and the probability of flowers would be less also.
When the plants are potted, the soil should be made firmer about their roots than is usually done for soft-wooded plants; and they may be returned to the propagating-bed and placed on the surface of it, or in some other place where the conditions will be somewhat the same, till they root afresh in the new soil, and are found to be growing both at root and top, when the young shoots may be pinched so as to furnish the plant with from six to eight shoots. With regard to pinching, it may be observed that perhaps to this being done too often and too late in the season, and to the plant being kept too long in heat, may be attributed the quantities of flowerless plants that are frequently to be seen. Better have half a dozen firm shoots well ripened and in a flowering condition than double that number in an imperfect state.
As soon as the young shoots break after being pinched, it will be better to shift the plants to a position nearer the glass where they will get plenty of air and light, and where they will make short-jointed stubby growth.
Frorn this date onwards (until the weather becomes warm enough to turn them out into a cold frame) there is no position that would suit them better than that of a low pit with a single hot-water pipe round it, where a regular temperature could be maintained, and where air could be given more or less during the greater part of the day without running the risk of doing injury to other things.
It is not, however, an absolute necessity that this should be the case, as the plants can be very well grown in any Cucumber pit, vinery, or plant-house where there is a little heat to start them in. In this case they should be carefully hardened off by removing them gradually into a lower temperature for some time before they are turned out into their summer quarters.
From 4 to 6 inch pots will be large enough to grow the plants in the first season - certainly for furnishing purposes the 4-inch size will be the best, as the plants in them will be the most likely to flower.
Before the plants are turned out into frames in June, or even where they are grown under the improved facilities elsewhere referred to in the shape of heated pits, their condition should be rigidly inspected, and if they are not in a sufficiently advanced state to undergo the change, they ought to be encouraged, by such means as are at command, to hasten that desirable condition of early well-developed growth before they are exposed to the atmosphere of a cold frame. At the same time, in a warm climate and in a "favourable season," there is no doubt but that these plants could be well managed without a particle of fire-heat after they had a little warmth to start them in; and their growth, although a little shorter than that made in a warmer and closer atmosphere, would be as certain, if not more so, to yield an abundance of flowers, provided it was thoroughly ripened in the autumn. When the plants are housed they ought to be kept near the light and only moderately supplied with water, as they are liable to suffer and lose their leaves if over-watered and kept in a low temperature. When they are required to come into flower, the temperature should be raised gradually to that of a warm greenhouse, and afterwards increased as circumstances may require.
Year-old plants that are trimmed back are treated much the same as plants that are raised from cuttings, except that in the latter case they do not require a high temperature at any time. They are partially shaken out and repotted, and when started in a gentle warmth they grow freely and make fine bushes the second season.
Although within the last few years this beautiful and useful greenhouse plant has been several times brought under the notice of your readers by various writers, it is astonishing that we see it so seldom adorning the stages of the amateur's greenhouse. When in full bloom, the appearance of the plant is highly effective. The flowers, which are of a tubular shape, red and yellow in colour, present a telling contrast with the rich glossy foliage, which is a striking feature of the plant. If a proper system of culture has been previously followed, the plants will begin flowering in November, and continue to flower for months. The particular plant in my possession began flowering at the time referred to, and is still in flower at this date (12th March). Younger plants will come on in succession. The propagation and culture of this plant are not necessarily a difficult matter, therefore good growers of the ordinary run of soft-wooded greenhouse plants need have no hesitation on that score in beginning with it. Cuttings of the young wood inserted in the usual light compost root readily at this season, when placed in a warm, moist temperature, and kept close and shaded.
When sufficiently rooted, they should at once be potted off into thumb pots, in a compost of loam, sand, and horse-droppings, or some bone-meal. If leaf-mould is mixed with the soil, it should be only a very little, as it causes a watery growth. Return the plants to the quarters they were struck in till they are established in the pots; and they will require shading from direct sunshine for a few days after being potted; and then two shifts, first into 4-inch, and lastly into 6-inch, pots, will in general be sufficient to grow plants large enough for ordinary purposes. Over-potting the plants should be guarded against, especially those wanted in flower before midwinter.
By timely attention to this matter much disappointment may be avoided. Plants in large pots are apt to continue in free growth till the season is too far advanced to insure the maturity of the young wood, upon which a crop of flowers depend. The plants do well grown in a cold pit or frame from June and onwards during the summer months, when they are attended regularly in regard to the usual items of watering, staking, tying, and pinching to keep them stocky.
The method of cultivation adopted by the "Squire's Gardener," which he detailed in your pages some years ago - viz., that of turning the plants out into earth-pits, is worth the attention of those whose labour power is limited, and who are expected to keep up large numbers of flowering-plants with, at best, inadequate means of doing so. I have adopted this method in the case of Cyclamens with good results. Unless a good position not far from the glass can be afforded them in the greenhouse, there need be no hurry in housing the plants in autumn, as they will do far better in a frame than when huddled along with other plants which already may have too little room. The flowers are produced freely in a comparatively cool greenhouse with a dry atmosphere. They should be carefully and regularly attended to with water in a tepid condition throughout the winter months.
D. Mackie. Ayrshire.