The Amateur's Greenhouse and Conservatory/Chapter 18

by Shirley Hibberd

 

CHAPTER XVIII.

ORCHIDS AND PITCHER PLANTS.

The Orchids and Pitcher plants adapted for greenhouse culture are not sufficiently appreciated, owing, no doubt, to the prevalent belief that all such plants require steaming stoves, and are utterly beyond the reach of amateurs, whose short purses compel them to the observance of limited liability. It so happens, however, that a very choice selection may be made of plants equally to be desired for their curious structure, interesting history, and high floral beauty, and that such a selection may be grown to perfection in any greenhouse with the aid of a little more care than such things as bedding plants require. The best place for a few of these plants is in a compartment shut in by means of a glass screen at the warmest end of a house that is heated during winter sufficient for the safe keeping of a good collection of miscellaneous greenhouse plants. But if a house be constructed expressly for cool Orchids, we should advise that it be a smallish span-roofed structure, much below the ground line, and with the roof no higher than needful to allow of head room, even allowing that the path through the house is reached by descending three or four steps. The place should be damp and warm and snug. One great aid to success will be to have the brickwork of its natural colour, and clothed with such creepers as Ficus repens, and to have as little woodwork in the place as possible, and to have no whitewashed, glaring surfaces anywhere to reflect a dry heat on the under sides of the leaves of the plants. A width of twelve feet will allow of a flat table on each side, which may be made with boards and covered with a layer of sand; but we should prefer to have a bank of the natural soil supported by brick walls next the path. A layer of sandy peat might be spread on the surface and planted with the common green lycopodium, Selaginella denticulata, and on this the pots could be stood on saucers turned bottom upwards. By arrangements of this kind a salutary humidity will be maintained in the atmosphere, and the orchids will be far more healthy and robust than if kept in a dry, woody, white-washed house, such as the Mexican succulents would delight in. Having made suitable provision for their comfort, the rest is easy, provided always that you do not attempt to grow stove orchids in greenhouse temperature, for in that you will certainly fail. Great things have been done of late years in the cool treatment of orchids, but there are certain kinds that require a high temperature and an abundance of atmospheric moisture, or they simply live without flowering, or, perhaps, instead of living, dwindle away. The selection at the end of this volume comprises all the best and safest for the amateur, every one of which may be grown to perfection in a suitable house by the adoption of the simple means we shall now describe.

There are two sections of orchids—the epiphytal, which grow on the branches of trees; and the terrestrial, which grow in soil. The epiphytal kinds can be grown fastened to blocks of wood, and be suspended from the roof, or in pots or baskets; but the terrestrial kinds must be grown in pots, and be potted in a compost consisting of turfy loam and peat in equal proportions, with the addition of a little leaf mould and silver sand. The epiphytes must have a compost much lighter than the above, and nothing can surpass a mixture of fibry peat, from which all the fine soil has been removed, and sphagnum moss, well mixed together. It is not necessary to be particular about proportions, because the whole of the epiphytes suitable for the greenhouse will grow in either peat or moss separately. Before using the latter, take the precaution to destroy all insect life that may be lurking in it, by putting it in boiling-hot water for a short time. Always effectually drain the pots; one half, or even two thirds, of the pot should be filled with broken potsherds. Place sufficient compost on the crocks to fill the pot to within an inch or so of the rim, and then spread out the roots on this, after carefully removing a large proportion of the old worn-out soil, and place a layer of the new material over them. If necessary a few pegs may be inserted to keep the soil in its place and the plants steady. To put them on blocks, simply fasten a little moss to the block with matting, and then spread out the roots over the block, and after placing a thin layer of moss over them, secure the plant to the block with copper wire. Cattleya citrina should always be grown on a block, with its leaves hanging downwards, because in its native habitats it always grows on the underside of the branches of trees. Terrestrial species must have good drainage, but they do not require potting so high as advised for the others. The best time for potting, or dividing the plants, is just as they start into growth.

The temperature should range from 55° to 75° from March to October, and from November to the end of February an average temperature of 10° lower than that advised for summer will be the most suitable. The atmosphere must be kept rather dry through the winter months, as the plants will then be at rest, but during the season of growth it must be kept constantly moist by frequently sprinkling the walls and floors; and in very hot weather a slight sprinkle overhead in the afternoon, when shutting up, will be of great service. Syringing the plants must, however, be done very carefully, or much harm will result. There is no fixed rule with regard to the application of water to the roots, and it may be taken for granted that when the plants are growing freely, a fresh supply will be required as soon as the soil begins to feel rather dry. If they are watered constantly, whether they require it or not, the roots will soon rot and the plants perish. Those growing on blocks must be dipped in a pail of tepid water every other day during the summer, but in the winter once in three weeks will be quite sufficient. Pot specimens, when at rest, only require enough moisture to prevent the leaves and pseudo-bulbs from shrivelling.

Shade sufficiently to prevent the sun scorching the foliage, but at the same time admit all the light possible to promote a robust growth. This is especially necessary after the middle of August to promote the perfect ripening of the growth of the summer, for if this is not well matured before winter it is impossible for the plants to flower satisfactorily or remain in good health for any length of time. Orchids require very little air in proportion to many other classes of plants, but the house must be ventilated sufficiently to maintain a pure atmosphere. In the winter scarcely any ventilation will be required, and the air must only be admitted in calm and genial weather.

The most useful of all the cool orchids are the Cattleyas, Lycastes, Oncidiums, and Cypripediums. The last genus supplies the most famous, because most useful, of all known varieties of greenhouse orchids, and the beautiful C. insigne, or lady's slipper. This is a most accommodating plant, for it will grow grandly in the stove, and flower there all the

CYPRIPEDIUM INSIGNE.

winter through, but it will also thrive in a snug greenhouse, and may be nicely grown in a fern case in the parlour, and, indeed, in skilful hands, it becoms a first-rate plant.

To grow a fine specimen, half fill the pots with large pot-sherds, over these place a layer of moss, and fill up with a mixture of mellow turfy loam or tough peat, with a fourth part of its bulk of small crocks and a few nodules of charcoal. In potting the plant, first loosen the roots carefully, and spread them out, and finish the potting in such a manner that the base of the plant will be elevated two or three inches above the rim of the pot. To do this it may be necessary to remove some of the soil from the pot first, but it is impossible to give directions for every particular. In any case the soil should be pressed about the roots moderately firm, and a coat of the finer part of the soil should be spead over the top for a finish.

If a very nice mellow loam is not obtainable, peat and sphagnum may be used instead, but a bit of first-rate turfy loam, of a hazel colour and “silky” to the touch, will grow a finer specimen than peat. While the plants are growing they must have regular supplies of water, but in winter they must be kept rather dry.

The pitcher plants, adapted to associate with the cool orchids, are those of America and Australia—Sarracenias, Darlingtonias, and Cephalotus. We must not think of Nepenthes, which requires the heat and moisture of the stove, or it becomes a plague to its sad possessor. But we have enough to afford a delightful change from the ordinary run of greenhouse subjects, and these plants are as curious as they are pretty. The coloured plate of Sarracenia Drummondi, published in the ‘Floral World’ for April, 1870, will convince any one who may be in doubt as to the ornamental uses of the family. As regards the production of pitchers, the plants now before us differ from the Indian pitcher plants in many particulars, and a short account of them will, we feel assured, be considered appropriate to the purpose of this work.

It will be observed, then, that the leaves of the Sarracenias are hollow cylinders, which terminate on one side in a trumpet kind of lip, like a vessel out of which fluid is to be poured, and on the other in a leafy appendage or lid. In the fully developed leaf we may notice that the principal beauty of the colouring is in this lid, which is sometimes of a dull purplish-red, sometimes snow-white, pencilled with carmine lines, and sometimes a delicate greenish-yellow. The leaf in its whole length is strengthened by an angular stem, which is very curiously produced; and when this is cut through it is seen to be exogenous, or an outside grower, a most surprising circumstance, botanically speaking, because, from what we are accustomed to in the forms of the vegetable kingdom, we should, until the fact were demonstrated, say that for certain these were endogenous or inside growers. It will be observed that the young pitchers have the lid fitting down quite close; but

SARRACENIA VARIOLARIS.

as the pitchers increase in size the lid gradually rises, and then we may suppose it possible that water can find its way into the pitcher by means of condensed dew or the fall of rain. Not that water does find its way in; no! But water is almost always found there; it is secreted by the plant. If you dissect a pitcher, you will find that the epidermis, both within and without, is pierced with stomata, and the cellular tissue beneath is of a spongy texture, the cells large, and destitute of spiral vessels. Inside the pitcher are numerous hairs, which project downward; and it is found that when an insect enters, its downward course is easy, but escape is almost impossible; hence we not only find water, but also flies, wood-lice, and even beetles. Ah! the way to ruin is smooth and sometimes pleasant, and to go down is easier than to go up: so perhaps the flies find it in the pitchers, as we do also in the conduct of life. Water may be found in the pitchers long before the lid has been opened to catch it; and pitchers full grown are found with not a drop in them; indeed, you may find pitchers full that never were exposed to rain, and that were not filled by the syringing of the plants by the cultivator. To clear up the difficulty, we took some plants and kept one half of them plunged in pans of water, and the other half were kept as dry as possible so as not to kill them. What was the result? The plants that stood in water, had full pitchers; and the plants that were kept drier than they should be, had empty ones. It was reasonable to conclude therefrom that the plant has the power of storing up surplus water against the day of want, and that what we find is usually secreted, though that they should be filled by rain is, of course, possible. How could it be otherwise if rain happened to fall when the pitchers were open? As to the flies, they are, no doubt, attracted by the moisture, and perhaps a little sweetness. Put a jar of water in a house where there are crickets, and it will contain plenty of drowned crickets next morning. What, then, is the wonder that flies, finding the pitchers open, and smelling the moisture, should be tempted to their destruction? An English naturalist once supposed that the ichneumon fly would drag other flies, and hurl them over the edge of the pitcher to destruction, as a human murderer might throw a victim over a bridge. There is no mystery about the flies being there. Watch long enough, and you will see them go down, but however long you watch you will never see them return. The moral is too obvious.

The Sarracenias are natives of the North-American continent—some of them (S. purpurea, most certainly) range as far north as Canada; but for the most part they inhabit the warmer parts of the temperate zone, and are always found in bogs. Thus we have a key to their culture, for nature sorts her plants into their suitable zones and climates, and we have but to take notice of the way she places them. It is certain that nature does not stew these plants in such a steam as the hottest of the orchids thrive in; yet many of our amateurs think there can be no place hot enough for them, and the consequence is the plants have no beauty, and, instead of spreading fast and forming great tufts, they dwindle away and are pronounced difficult plants to cultivate. The soil generally used is peat, and, as a rule, this cannot be surpassed, though the beautiful S. variolaris may be grown in pure sphagnum, in the coolest and airiest part of the stove; and an admixture of soft stone with the peat or sphagnum is useful. The orchid grower will understand their requirements when advised that the soil which suits a Cattleya will suit a Sarracenia.

They require a certain degree of warmth with air, but must never be exposed to wind, more especially a drying wind, nor, as before remarked, to a great heat. They must have water, and they must have light. Shading is most injurious, and quite destroys the beauty of the pitchers. The best way to dispose of them is to place them on a shelf of an intermediate house or warm greenhouse, very near to the glass. S. purpurea does not need so much heat as even an intermediate house, and. it may be grown as well in a frame as a greenhouse.

It is essential to keep these plants cool in winter, that they may rest naturally, as they do in their native bogs, where they are sometimes subjected to much cold—to freezing, in fact; though such as S. variolaris will not bear frost when under cultivation, and at all times needs more warmth than the others. A moist air is good for them at all times. All about them should be frequently made wet, to cause a plentiful dew; nd as to what they stand on, let it be a solid bench, not a bed of soil or a trellis, for in either of such positions they may be subjected, to excess of evaporation from the too rapid movement of the air around them. Keep in remembrance that they are bog plants; they stand in water, they are bathed in vapour, yet they have fresh air and sunshine. These conditions they need when under cultivation. In

SARRACENIA DRUMMONDI. (Flower just expanded.)

respect of propagation, that is easily accomplished by division of the root.

Of the species there are not many. The most useful is S. Drummondi, of which there are several varieties, alba being perhaps the best. This is of tall growth. The pitchers are nearly a yard high. The lid is most delicately veined with carmine, on a creamy pale green or snow-white ground. The flowers are dull purplish red, handsome and peculiar. The variety of Drummondi called rubra has pitchers richly veined, red and pale green; the flowers mount high above them, and are of a great size, and a most beautiful purplish red colour.

S. flava is also a tall kind, the pitchers being two and a half feet high, and the flowers a trifle taller. The latter are

A, Leaf of Sarracenia flava; B, Leaf of Sarracenia purpurea;
C, Leaf of Darlingtonia Californica.

yellowish-green, quite transparent; the pitchers also are the same colour. It is a fine species. There is a variety of this called picta, which is more distinctly veined than the species.

S. purpurea is very dwarf, with large pouch-like pitchers distended in the middle. The colour of the pitchers is reddish, shading to dull green. The flowers are a fine red colour. This is the easiest to obtain, and the hardiest of them all. In a sheltered position in a bog it would live through the year in any part of England.

S. variolaris has the lid of the pitcher bent over the mouth of the tube in a manner different to all the rest. It is a beautiful variety, of large growth, and has yellow flowers. The lid of the pitcher is purplish red, spotted with white.

S. psittacina is a miniature, with small pitchers which spread horizontally, with a kind of inverted hood for a lid. The appearance of a perfect pitcher of this is that of a parrot’s head reversed, as when a parrot suspends itself head downwards from its perch. The pitchers are dull red, spotted with white, and the flowers are deep sanguineous red.

Darlingtonia Californica is an interesting alliance of the Sarracenias. It has a curious pitcher, the lid of which forms a perfect hood, from the inner edge of which the true leaf is produced. The hood is usually so placed as to completely exclude rain, yet moisture and dead flies are commonly found in the pitchers.

CEPHALOTUS FOLLICULARIS.

The Australian pitcher plant Cephalotus follicularis is a native of the swampy lands of the south-west of Australia, more especially in the neighbourhood of King George's Sound It is extremely pretty and it presents a problem to the vegetable physiologist, for its pitchers are developed apart from the leaves (if they are leaves), and the plant always presents examples of two distinct forms of foliation. It has no stem, but grows in a close tuft amidst the wet moss which forms its bed, and when it flowers presents a near resemblance in its floral organs to a ranunculus.

The Cephalotus has been grown to perfection in a warm greenhouse, and may be associated with either Sarracenias or Nepenthes; but its proper place, as regards temperature, is midway between them. The soil best adapted for the plant is a mixture of chopped sphagnum and the fibre of peat, without any of the earthy matter, with an admixture of potsherds broken to the size of peas. It should not stand in pans of water; but plenty of water it must have, in common with its associates; and if the atmosphere of the house in which the plant is grown does not happen to be saturated with moisture it must be covered with a bell glass, which should be cleaned daily. The best place for it in a plant collection will be where the temperature averages 45° to 55° through the winter, and 60° to 80° through the summer.

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