With the appearance of the long-awaited first flower in his green­house, the amateur quite justifiably feels a warm glow of achieve­ment and pride. He will find, however, that this is no time to bask in the glory of the moment, for, almost overnight, the green­house has quickened with life. New growths glow a healthy red and the emerald-green tips of new roots peep from the potting mixture and even from breaks that are apparently dead roots. These are signals that the potting season is at hand.

The demand of the orchid for periodic repotting is another characteristic setting it apart from other plants grown under arti­ficial conditions. It is common to most orchids out of their native environment. Just as important as housing and balance, repotting may appear to present almost insuperable obstacles to the inex­perienced grower. The difficulties, if advice against overcrowding the greenhouse has been heeded, will not prove to be so great.

Repotting is not something that can well be postponed, for, once the precise moment for repotting is past, it is best to hold the plant over for another year—the only exception to this being in extreme cases involving the life of the plant. This enforced holdover may result in retarded development and the appearance of a smaller new bulb. Next season's flowers may be fewer and poorer or there may be no flowering at all. It is one of the para­doxes of orchid growing that the plants require repotting at
regular intervals, yet they resent shock and suffer from the pro­cedure if every circumstance is not just right.

The best time to repot varies by genus but in most cases it is soon after flowering when the live eye at the base of the most recent pseudobulb begins to swell and form a new growth. It should never be done unless the plant is in active growth. Repot­ting in flower sheath is inadvisable, since it usually results in loss of the flower. The ideal moment is just before the tiny new roots break through the tissue. If the plant can be caught at just this time and repotted without injury to these budding roots, they will immediately take hold of the new medium and the shock will be comparatively slight.

There are some plants that are such prolific and vigorous growers that they put out new growth and a flower sheath at the same time. In such cases it will be wise to repot when the bulb has attained a size larger than that of the previous year, provided that no dark shadow of bud appears at the base of the flower sheath when the plant is held to the light, and that the roots show sign of strong and immediate growth.

Friends of orchidists often remark that growers spend much time in the greenhouse, seemingly doing nothing but brooding over the plants. But there is purpose in this 'brooding.' Careful inspection of the base of bulbs will occasionally reveal a need for repotting that would be missed by cursory observation. If growth of the new bulb progresses too far or if the roots become too long, it is almost impossible to repot without knocking them off. New growths appear as though by magic but may remain unde­tected for a considerable time unless the plant is watched closely. It is an incidental reward of such care that other damage may be avoided. The base of a bulb is a favorite hiding place for scale, and the pest may have injured the new shoot before being dis­covered. Sometimes, too, it is found that the new eye has been buried in the medium and the new growth has rotted off. Careful removal of surplus compost with the tweezers will free the base of the bulb without injuring the plant.

Aside from the known requirements of a particular orchid, to be learned by experience and research, there are certain indica­tions of a need for repotting that will be obvious to any beginner. One such sign, although not always to be trusted because of the sprawling nature of some roots, is the appearance of many roots ranging out of the pot and over the potting material. There is an urgent need for repotting when new bulbs are crowding or over­hanging the edge of the pot or climbing awkwardly in the air. Repotting should have taken place long before such conditions appeared and the plant may be retarded by this neglect. Equally obvious is the case of a plant that has exhausted its compost. The compost will appear entirely decomposed and will feel spongy and soggy. In spite of the risk involved in potting at the wrong time, it is best to remove plants at once from such unhealthy conditions, since otherwise rotting of the roots, loss of leaves, and death of the plant may result.

The question of the most suitable material for potting orchids is a matter of considerable debate among hobbyists. In making a decision it will be wise to refer to the native environment of the orchid. Many of the showy orchids popular among amateurs are aerial-rooted epiphytes, receiving much of their sustenance from mineral salts in the moisture of the jungle air and from the debris washed into the crotches of trees on which the plants hang for support. It cannot be expected that they will thrive after being cramped and packed in ordinary garden potting material. A spe­cial medium is required—some coarse, fibrous, and porous sub­stance with an acid reaction of 4.5 to 5, which will not decom­pose too rapidly and so make the need for repotting too frequent.

English growers formerly used with success a native fibrous peat, but the supply of this material is near exhaustion. Since the war many fine British and Continental orchid collections have suffered from the lack of suitable potting media. Potting in trop­ical localities, where orchids can be brought in from the jungles and hung in the garden, presents no difficulties. Cocoanut half-shells with broken shells for a medium are frequently used. Manuring is usually an essential part of such outdoor culture.

While the problem of the American grower is not so easily solved as that of the orchid enthusiast in the tropics, he is more fortunate than European orchidists. The special needs of orchids are met very satisfactorily by the use of Osmunda fiber—the root of the cinnamon fern, either Osmunda cinnamonea or Osmunda Claytonia. In addition to providing the required drainage and pH, it is clean, easily handled, sufficient in itself as a medium for most orchids, and found in abundant quantities in New Jersey, Indiana, and the swamps of Florida.

The only rival of Osmunda as a general orchid-potting medium is Polypodium, root of the fern Polypodium vulgare. It is found over much of the world, with the Pacific Northwest of the United States as a favored locale. In certain respects Polypodium is better than Osmunda. It decomposes as rapidly and has a finer texture, particularly suitable for tiny seedlings, backbulbs, and sick plants. A mixture of chopped, live sphagnum moss and finely chopped Polypodium is a recommended formula for plants in poor condi­tion. The drawbacks of Polypodium, however, still make Os­munda the choice of most growers: it is more difficult to water plants in Polypodium; if not saturated it dries out more quickly; and when saturated it does not drain so well. It is difficult to change plants from Polypodium to other media without setbacks.

Proper equipment is the next requirement for a successful re­potting operation. A sharp, strong knife will be needed to make a clean cutting of roots clinging to the pot. A screw driver is valuable for freeing the compost and plant without damaging plant or pot. It is also handy for tucking compost into tiny seed­ling pots. Some type of shears will be indispensable. Grape shears with long, slightly curving, pointed blades are excellent.

The potting tool proper is often a matter of the grower's in­genuity. Many types are in use. Highly recommended is a piece of hardwood (such as a broom handle) about 12 inches long and from 1 1/2to 1 3/4 inches thick, smoothed to fit the palm at one end and sharpened to a point, or flattened to a sharp wedge, at the other. Some growers prefer a metal tool, since it allows the use of more pressure in packing the medium firmly. This may be a flat blade of heavy metal about 1/2 inch thick and 1 to 1 1/2 inches wide, shaped to an 'L,' and filed to a flat, mod­erately sharp edge at one end. The other end may be covered with a piece of rubber hose to protect the hand.

Some growers use stakes of redwood or bamboo to support weak or leaning bulbs, but supports of heavy galvanized wire, cut to a suitable length, will best survive the continued damp. String or flat dental floss may be used for tying material; raffia is not advisable as it deteriorates too rapidly when it dries out.

Tweezers are useful for removing dead tissue from the bulbs and decomposed compost from roots. At times the dry tissue at the base of the new bulb may become chilled when wet and a wet fungus sets in that may affect the entire bulb if not re­moved. Care should be taken not to injure the dormant next-year growth under this tissue.

The type of container used will depend on both the need of the individual plant and the taste of the grower. Pots are most suited to Cattleya and allied genera, to Cymbidiums grown under glass, and Cypripediums. On the West Coast, where plants will not dry out too rapidly, fern or half pans may be used. Deeper containers are needed in hot and dry climates. Phalaenopsis can be grown in pots or baskets. Oncidiums and Wanda coerulea thrive on rafts of bark or blocks of wood. Potting material may be tied firmly around the base of the plant and container with wire, allowing the air-loving roots to wander at will.

Certain plants (all Vandas, some Laelias, and Coelogyne cris-tata) react so badly to repotting that it is best to resort to other expediencies. Decomposed material may be removed from be­tween the roots with tweezers and fresh material gently tucked in its place. In the case of Laelias in baskets, with roots ranging far outside, fresh material in the form of a feed bag may be wired around the outside of the basket. After fresh material is tucked around Coelogyne cristata, the bulbs that are growing in wild abandon may be fastened back in place with wire hairpins.

In selecting the proper-sized pot for a plant, choice is governed by the health, size, and habit of growth of the particular orchid. For example, plants such as the Cattleyas, with a running rhizome-type of growth, may be potted to allow for two years of growth, a growth to a year, and an inch of pot to a growth. Generally, a large healthy plant will require a large pot, while a weaker, slower-growing plant needs a smaller one. A sickly plant may sometimes be brought back to health by confining it to a small pot.

Overpotting, an error which many beginners make, is a costly practice. The roots of the plant will not be able to absorb all the moisture in a large pot. Excessive moisture settles in pockets in the potting medium and rapidly decomposes the compost. When this condition prevails, roots tend to rot off, bulbs shrivel, and leaves turn yellow. An inexperienced grower, concluding that these symptoms are caused by a lack of water, may overwater, complet­ing the damage to the roots and killing the plant.

Cleanliness is important in repotting. Old pots and crock (broken bits of pots used in the bottom of a pot for aeration and drainage) should be scrubbed thoroughly. New pots should be soaked for a time.

As a concluding word on the subject of equipment, the grower should remember that 'A proper place for everything and every­thing in its proper place' is a wise maxim. The best arrangement is to have a clean, light potting shed adjacent to the greenhouse. The major furnishing of this shed should be a potting bench of a height suited to the potter. A comfortable height is advisable, or potting may become a back-breaking job.

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