Right here is as good a time as any to stop £or a moment and take a deep breath—to remind yourself again that orchids aren't basically different from other plants. This may be hard to do if you have just finished reading about the care and work that go into orchid seed germination. However, can you recall the patience and skill that are necessary to germinate tuberous begonia seeds, or pansies for that matter? Some bromeliads give even more trouble and offer less success with their seeds than most orchids do. The probabilities are, though, that you will never sow as much as one orchid seed; but a knowledge of the technique makes asexual propagation of orchids very easy and simple by comparison.

Well cared for orchids increase in size from year to year and they may be divided, split apart, and reproduced by cuttings. In this respect they are like the garden plants with which you are familiar. The same methods of division also are used, although applied a bit more carefully. The only tool you need is a sharp, thin-bladed knife.

The time of the year when you can divide orchids depends upon the plants themselves, and the school of propagation to which you may belong. Many orchidists divide plants immediately after blooming; others, just before bloom sheaths appear. Most wait until new leads are well developed. There is even considerable discussion about the merits of fall or spring propagations. All of these methods of timing propagations are good—if they work for you.

Normally, the best time to make propagations is in the period after flowering stops and before new leads are too long. A good rule for most orchids is to watch the leads. When they are about an inch or two long they will initiate roots. This evidence of increased activity is called a "root collar," and when it just begins to show—that is the time to propagate. Root collars may occur at any season of the year with hybrids that make more than one seasonal growth. Species are more accurate about their timing. Never wait too long to make propagations. New roots, once they begin to elongate, are very brittle and are easily damaged.

There are four methods of propagation: offsets, layering, division, and cuttings. These cannot be used indiscriminately. You will have to select the method in keeping with the physical characteristics of the plant. Propagations are made just after new growth appears, usually in conjunction with repotting.

Monopodial orchids are propagated by air layering. The same technique is used for orchids as for other plants. A piece of osmunda (or of sphagnum moss) several inches thick is tied loosely around the stem at the place where you previously have made a slanting cut halfway through the stem. The cut is made three or more leaves below the top, three or more above the bottom. It is not advisable to propagate a plant with less than five leaves, although with care it can be done. Keep the osmunda moist. As roots develop on the upper portion, confine them to the osmunda, or add more osmunda. When sufficient roots have developed, cut through the stem, remove the upper portion, and repot; water occasionally and lightly for a few weeks in order to force vigorous root action. The main part of the plant will send up a new shoot from the axil of one of the leaves.

 
METHODS OF PROPAGATION

Top: Division; Adventitious Bottom: Layering; Cutting

Some authorities recommend that all cut surfaces be dusted with sulfur or covered with a thin, weak Bordeaux paste. The practice is of doubtful value, but it is better to err on the side of safety. A lapse of a day or so in repotting will allow the wound to dry out and will insure success.

Sympodial orchids, on the other hand, are increased by division, a standard garden practice you have followed in breaking up large clumps of phlox, irises, and other perennials. Except for Calanthe vestita and a few other deciduous orchids, sympodials never should be separated into less than three pseudobulbs to a division. The pseudobulbs supply food to the plant until new roots enable it to forage for itself. One pseudobulb to a division doesn't give it a fair chance of survival.

Divide the orchid clump by cutting through the connective stem between the pseudobulbs. Use care not to make the cut too close to a pseudobulb or you may injure one of the dormant eyes from which growth develops. Examine the base of a pseudobulb and you can see the eyes-small, flattened, cone-shaped protuberances.

Take the front division (the three or more pseudobulbs on the growing end), if it has good roots, and pot it up. The rear portion (designated as back bulbs) may have no roots at all. Stand it up on a flat of moist sand in a warm, shady, humid spot, syringe the foliage once or twice daily, and wait until it sends out a lead. When the lead is about an inch long and root primordia are barely showing, pot the division.

You will have difficulty in getting the back bulbs to stand erect since there are no roots long enough to hold them. Pack osmunda into the pot first, and rest the back bulbs on it, stapling them in place with one or two stiff U-shaped wires. A short piece of heavy galvanized wire may be pushed into the osmunda, and the tops of the pseudobulbs tied to it.

After potting, divisions are watered sparingly and occasionally until root growth is strong. Spray the leaves of the back bulbs daily to help hold down water loss from the plant. Keep them warm and shaded. When propagations are established, treat them as you do your other orchids. Sometimes the growth from back bulbs matures small, or fails to bloom. But the second season's growth usually will produce full-sized flowering pseudobulbs.

You can also propagate orchids without removing them from the original pot. By notching the rhizome you can develop extra leads and triple the size of a plant in a few years. This is the way large specimen plants are made.

Between each third and fourth pseudobulb make a cut halfway through the upper part of the rhizome. The rear pseudobulbs still receive some food from the leading portion, but, finding themselves more or less disconnected, they force dormant eyes into growth. It is possible by notching orchids to induce as many as three and four flowering growths on a single plant.

A few orchids, notably the weedy epidendrums, often reproduce themselves by means of adventitious plants. Apparently insect pollination cannot be relied on under natural conditions, and small plants are initiated on the nodes of pseudobulbs or on the "nodes" of flower stems. (Adventitious plants, also, are a means by which some orchids climb trees). A node is a slight lump where leaves have been, or are growing, or a joint in flower stems. This method of propagation is called "offset." After adventitious plants reach two or more inches in length, roots appear, and they can be removed and potted.

The common garden practice of making cuttings lends itself primarily to two members of the orchid tribe: the "nodular" dendrobiums and epidendrums. A stem is cut from the plant and sliced into sections, each containing three nodes or three leaves. The cuttings are placed on moist sand and kept in a gently warmed, moist, and shady spot. Small plants are initiated at the nodes. After roots develop the plants may be cut off and potted. Temporarily, they require continued shading, little moisture in the compost, and frequent syringing until they are well established, a matter of a month or six weeks.

Ordinarily it is advisable to have some location in the garden where you can carry on propagations until they are established. A heated cold frame, an extra Wardian case, or a glass box will release you from much worry and care, although the warmest and shadiest end of a greenhouse is also suitable. Propagations require more shade, higher temperatures, and more humidity than the parent plants.

After becoming established, propagations go through a period of hardening which is the same as the garden practice for flatted plants, gradually exposing them to more light, air, and water until acclimated to their normal environment.

All in all, if you use the same care and common sense in dividing and potting orchids that you would in separating clumps of dahlias and peonies, or in making cuttings of Saintpaulias, no further instruction is necessary.

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