Chapter - 06

Orchids In The Garden

Nearly all orchids are benefited by a period in the garden. There is something about outdoor life, no matter how short the period, that imparts vigor to them, ripens their pseudobulbs, and prepares them for heavy flowering. European gardeners stumbled onto this fact a long time ago. Several varieties of Mexican orchids, including the Flor de Maio (Laelia majalis), did not flower until placed outdoors from April through October. The famous South African Flower of the Gods (Disa grandi-flora) wasn't cultured successfully until it was grown the year round in unheated cold frames. Most terrestrial orchids flower better when summer-hardened under laths or in the filtered light under trees.

English gardeners grow orchids in wooden baskets and rafts and hang them from oak trees. Mediterranean hobbyists leave orchids in clay pots, sinking them in the ground near azaleas or clumping them with ferns near sheltered terraces. In Mexico orchids are used for patio decoration, along with more commonly grown tuberous begonias and fuchsias.

American gardeners have been indifferent to these natural plantings, although Nehrling in Florida years ago achieved excellent success with tree and open plantings of exotic orchids. Incidentally, it is not commonly known that Florida has eighty-four indigenous orchids, some of which are found as far north as South Carolina, Georgia, and Alabama. Orchidists in these states can have a field holiday most of the year growing orchids as they should be grown—in the open garden. Only recently have gardeners in these states, and in California and southern Texas, combined orchids with ginger, azaleas, and camellias in permanent outdoor beds. In more northerly sections some have been wintered in sheltered and protected patios, although this is frequently difficult to accomplish.

ENCLOSED PATIO

Actually, many orchids can be grown outdoors, provided suitable conditions can be found for them—but there's the hitch. Orchids with high humidity or warmth requirements never do become acclimated to North America. For the hardier orchids it is often difficult to find acceptable conditions in many portions of the United States. The spring-to-fall growing season may be short. In actual practice you are limited to the time between the last frost of spring and the first frost of autumn. The weather may be too hot, too dry, or too windy. Nevertheless, knowing the limitations of your climate, you frequently can supply artificially the missing requirements for normal orchid growth.

In the San Fernando Valley of California, where frost may last several months, an enthusiast has installed a battery of infrared lamps above the orchids in a lath house. Infrared lamps do not necessarily protect orchids from frost. But the air temperature is raised enough to prevent the frost from accumulating in dangerous quantities. In the dry atmosphere of Arizona, amateurs use cloth shields and houses to shade orchids and to help provide humidity by slowing down water evaporation from moist ground. Wind is a problem in Wyoming, but several gardeners have overcome it by using glass and wood folding screens to break the force of the wind. Northwest gardeners frequently use glass shields to help conserve warmth from the winter sun. It isn't the winter sun that is cold, but uninterrupted wind and the cold radiation from chilled earth. Of course, in most of these rigorous climates, outdoor orchid gardening is at best only a summer pastime. But you can have a lot of fun with it.

Orchids grown in the garden often do not require so much attention as when house cultured. Drafts are not a problem. Temperature changes are usually gradual. Humidity is created by hosing orchid foliage or the adjacent ground as often as necessary. Watering the pots may be a bit more frequent, but is no job at all with a hose. The difficulty—if any—will lie in the selection of a convenient and suitable garden spot for your orchids.

It is hard to be arbitrary about garden locations; orchids have succeeded in many places. The most unlikely spot, if care is exercised, can be made to grow lovely specimens. For the beginner a cool, semi-shady porch or terrace is probably the best starting point. The plants are easily accessible and can be closely watched for danger signs until a gardener acquires confidence. A brick porch or flagstone terrace is simple to keep moist. A wood porch can be protected by a strip of tar paper or galvanized tin over which a layer of moist gravel is spread.

The selection of a garden location should be made only after mature deliberation. It must have, ideally, the following characteristics: It must be open, permitting free air circulation. It should have some shade—a light, cheerful sort of shade, not heavy or dense. Study the filtered light beneath a single oak tree; that is about right. It must be as cool as possible in summer, as warm as possible in winter, with a natural hedge or high fence to block strong or cold air currents. Finally, there should be as much natural moisture in the air as possible.

The best garden location is frequently found in slightly shaded dells where daffodils have naturalized themselves. An excellent spot is an odd corner of the garden where a large tree, such as an oak, apple, or bay tree, casts enough shade to lower summer heat appreciably. A huge oak is nearly perfect, since the water transpired by its leaves is enough to supply the needs of an average family for cooking, drinking, and bathing for several years. It is sometimes enough to take the edge off dry air, to moisten and cool it. A small ravine partly shaded by trees, by rock outcroppings, or by a judicious use of lath can be a perfect setting.

Establishing orchids on trees is something of a trick. Unless expertly and correctly done they are likely to die. The roots must be tight against the bark. Preferably only the trees with rough bark should be used. Select a strong, healthy plant and knock it out of the pot. Clean the roots thoroughly of the potting compost. Spread the roots out and place them on a tree limb. Put an inch layer of sphagnum moss (osmunda may dry too rapidly) over the roots, holding the sphagnum tightly in place by nailing one-fourth-inch mesh chicken wire over it. When you finish placing the orchid, water it well, and water it every two days thereafter until it is well established. It is sometimes best to tie orchids to vertical limbs rather than to horizontal or sloping ones. Native rats and squirrels like succulent orchids, but they don't like to work too hard on vertical branches for their meals.

Unless you live in one of the milder sections of the United States never try to naturalize orchids in your garden. It is safer and more decorative to grow orchids in pots, where they can be treated individually and given water, food, and sunlight as necessary. Potted orchids can be moved about the garden as you see fit. If one location disagrees with them, it is simple to move them to another. They can be carried into the house when in bloom or massed for an exotic effect on the porch. They can be strapped to or hung from trees, or the pots plunged into prepared garden beds as your fancy may dictate.

In obtaining additional humidity by hosing plants or the ground with a broken stream of water, remember that the force of the spraying may be detrimental to the plants. Water shot into the interstices of the stems and leaves may cause rots. The best method is to buy a spray arm, the kind that comes with hand-pump spray guns. It can easily be adapted to fit on the garden hose. In operation it creates a thick, fine mist that settles softly on orchid foliage and rapidly disperses through the air. Some western gardeners have gone so far as to wire half-inch galvanized pipes to oak trees, attaching mist spray heads to the pipes just above the level of the first branches. The sprays are started by time clocks and run for a few minutes each hour; or are controlled by a humidistat.

Even though your house is porchless, your garden tree less, and your land plumb level, you can grow orchids out` doors. Several pieces of muslin stretched on a rack above the plants furnish ample shade and protection from strong sunlight. The moving shade furnished by laths set their own distance apart is ideal. Cloth houses and lath houses are reasonably inexpensive, simple to build and maintain. A cloth house builds up an astonishing amount of humidity despite the porousness of the cloth. If tacks and lath bracings are used, the cloth house can be rolled up and put away for winter, quickly erected the following summer.

LATH HOUSES

A lath house is a subject to itself. It has its own rules and practices. It is an invaluable adjunct to gardening, no matter where you live. It frequently serves the dual purpose of growing shade-loving plants and, when architecturally joined to your house, furnishing you with an outdoor living room. Inside a well-managed lath house the temperature may be 10°, or more, cooler than exposed areas, and the light and air inside are soft. A bricked-in area, large enough to take several chairs and a swing, will give you a comfortable feeling on warm days.

In some sections of Missouri, Texas, and California it is not uncommon to find lath houses equipped with humidifiers. On the upwind side one or more vegetable mist sprays or mist sprinklers are placed one-third up the lath walls and are connected to the water system. The sprays are operated intermittently or steadily, depending on the weather. The water vapor drifting through the lath house cools and humidifies it.

The size of a lath house and the form it takes are dependent only on your pocketbook, the area available in your garden, and whether you want a utilitarian or fancy structure. It has been estimated by commercial growers that a simple lath house will cost from thirty-five to seventy five cents a square foot. The variation is in the amount of carpentering you can do yourself and the kind of wood you use. Redwood or cypress will weather much better and last longer than most woods. The shape a lath house takes is immaterial as long as it permits about 50 per cent of the sunlight to filter through. Some gardeners admire the neat appearance of a gable roof; others prefer the less expensive flat type. Lath houses may be square, round, pergola-like, or any combination of shapes. One western gardener has a lath house that resembles a small summer cottage. The two important and invariable features of a lath house are: (1) the laths on the roof must run north and south; (2) the side laths must be vertical.

LATH HOUSE

The best practice, before building a lath house, is to make a preliminary study of plans in published books on the subject. The Washington office of the Department of Agriculture and your local Farm Advisor have several free pamphlets which answer technical questions.

In all the years that lath houses have been used, only one improvement has been made on them—the staggered lath roof. This roof was developed because ordinary lath roofs didn't give plants enough light during early mornings and late afternoons, the slanting rays of the sun being obstructed by the single horizontal layer of roof laths laid their own widths apart. In the staggered arrangement, laths are laid in two series, one above the other. The first lath is nailed to the top side of the support rail, and the second and succeeding laths are laid three widths apart. On top of this first series, and parallel with the supports, a runner three-quarters to one inch thick is nailed. The second series of laths, centered between those laid first, is nailed to the top of the runner. This arrangement permits morning and afternoon light to enter almost unhampered. Yet midday sunlight is no greater inside the staggered lath house than when laths are placed in the old manner on one level.

Some Eastern growers and amateurs have wintered plants in severe climates satisfactorily in lath houses covered with heavy butcher paper—a Manila wrapper that has a strong tensile quality. Run the paper through, or paint it with linseed oil, which makes it semi transparent and waterproof. Cover the sides of the lath house and the top, too, if necessary. Draw the paper tight and hold it in place with nailed laths. Place a kerosene heater in the center of the lath house; it will take the chill off cold air. This is not so good or so safe as a greenhouse; but it is inexpensive, and it will help to protect your plants if you check it frequently.

There have been many debates about the value of lath houses in those parts of the United States where the summer is short and the winter severe. For actual value received, in a monetary sense, northern and eastern gardeners get a very low return. Semipermanent and collapsible lath structures may prove more advisable for them. But for the majority of gardeners in less extreme climates a lath house adds to the enjoyment of gardening. The larger number of plants, including orchids, that can be summered under lath makes this piece of equipment a means to greater gardening pleasure.

When autumn comes in the northern and eastern states, it is time to think about protecting your orchids from imminent frosts or snows. If you have many orchids, it will be necessary for you to have a special place in which those not in bloom can be wintered, a place where they can grow between temporary periods of being house or garden guests. For this purpose there are few structures better than a cold frame. In the South it is used alone. In the northern states it is improved with electric heat. With a heated frame—as with a Wardian case—you aren't limited to hardy orchids. You can include a few of the lovely warm orchids in your collection.

A cold frame is a small wood structure covered with glass sashes and not heated artificially. When you add a heating element, it becomes a hotbed or, in practice, a miniature greenhouse. If you are already a gardener, you are probably familiar with the value of both heated and unheated frames. A cold frame will protect plants from frost; a hotbed provides additional warmth against snow. Both help you get a jump on nature by simulating the springtime warmth and humidity which plants need for their early start in life. This simulated spring is excellent for orchids. European gardeners have known this for over ninety years and have used cold frames and hotbeds con tinuously for orchid culture.

In the past, many amateurs hesitated to use cold frames because of inexperience. Today, inexperience is no longer an excuse. Scientists have made cold frames nearly foolproof; you can succeed almost in spite of yourself. It is a simple matter to buy commercial sashes and cold frames ready-cut from cypress or redwood and to bolt the whole thing together. Ready-cut cold frames cost so little that, unless you are a hobby carpenter, they are preferable to homemade frames. Some gardening firms now offer durable frames of lightweight steel that are completely portable. They can be quickly knocked down and stored in summer, as quickly rebuilt for winter.

On the Pacific Coast and in many eastern states cold frames have been built from bricks, cement, and tile. They are usually attached to a wall of the house as an interesting architectural feature. Some have been placed against the south walls of garages, built high enough so they can be entered from the garage by a door. In a sense, these larger cold frames are small lean-to greenhouses.

Ordinarily, cold frames are transformed into hotbeds by thermal cables laid on top of the soil, or several inches below it. Such cables are excellent for stimulating germination of seed and root growth, but they are not practicable for orchids where light and air temperatures are the important factors. Thermal cables strung around the walls of a cold frame, just above soil level, have been useful for promoting good orchid growth in mild climates. In harsh climates the heat output is not high enough to counteract wintry cold.

The amazing advances in electric lighting for stimulating the growth of common garden plants has also shown that ordinary twenty-five-watt lamps may be substituted for thermal cables to heat cold frames, even under the most severe conditions. The Minnesota Agricultural Experiment Station found that cold frames heated by lamps were superior to cable-heated frames. Plant growth was more rapid owing to the additional light supplied by the lamps, and the plants themselves were sturdier. The inside air temperature of the cold frames did not fall below 38° F., although the outside temperature dropped to 15° below zero. Tests at Ohio State University and other experiment stations showed that electric lamps were superior to many other forms of heating cold frames. Applied to orchids, lamp-heated frames.have proved to be the nearly perfect solution for orchid culture on a very small scale.

FRAME HEATED BY ELECTRIC LAMPS

The cost of installing electric lamps and a thermostat in the average cold frame has been estimated at $5.00, the cost of operation at a maximum of $1.50 a month during the winter. This is relatively inexpensive when one considers that a standard frame will hold fifty or more orchids.

Should you go in for cold-frame or hotbed culture of orchids, there are several things that will make your work easier. If you know anything about greenhouses, just remember that cold frames and hotbeds operate in the same way, except on a much smaller scale. If you are new to the use of frames, bear in mind that they should have a southern exposure, should be protected from wind, and should be kept away from shade. A minimum temperature of 50° F. is desirable. Try to keep the temperature below 90° in summer by judicious use of muslin shade—lath may be better. Ventilate the frame as much as possible on warm days, even in winter, by opening the sash a few inches or more as the weather warrants. Considerable humidity can be maintained by sprinkling the ground inside the frame several times weekly in winter, daily in summer.

It is not a good practice to set orchid plants directly on the soil inside cold frames. Place them on racks a few inches above the soil level, or plunge the pots up to their rims in six inches of pea gravel. Gravel or cinders on top of the soil in frames will help to maintain humidity and will discourage crawling pests.

During snowstorms, blizzards, and prolonged cold weather it may become necessary to cover the sashes with insulating material, such as felt or straw mattresses, at night. In all except extreme cases, heat from four or six lamps is sufficient to keep the temperature at the desired level.

If you plan to grow small orchids, those whose foliage rarely goes higher than eighteen inches, standard frames will be satisfactory. If you want larger orchids, and those with three-foot flower spikes, you will need a higher frame. A commercial frame with a foot or two of lumber added to the bottom will give you considerable leeway in growing a variety of orchids.

When you get right down to it, the culture of orchids, like that of other garden plants, is limited only by your imagination and ingenuity—provided that you understand the minimum requirements of your plants and treat them as children who may be indulged but never allowed out of control. If you do that, you can improvise frames like those of the amateur in Arizona who uses grapefruit crates in which to grow orchids. He puts sand on the bottom, sets in his plants, and covers the crate with a pane of glass.

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