Mimicking How Some Orchids Grow in Nature Leads to Spectacular Results
It is safe to say that the majority of orchid hobbyists, myself included, came to the world of orchids after success in other facets of gardening and horticulture. Perhaps that is why most of us doggedly pursue the practice of confining and cultivating our orchid plants in some variation of a traditional flower pot. We also carry, I suspect, an ingrained aversion to exposed roots on any plant. Yet this is contrary to the way in which epiphytic tropical orchids are found in nature.
It took me a while to develop the confidence necessary to subject a few of my plants to life without the security that terra cotta or plastic seems to provide. But after some success, I am growing an increasing number of plants au naturel.
Certainly you need a reasonably humid environment for this technique to succeed, and part of my initial reluctance was based on the fact that I developed my orchid growing skills in a semi-arid region. Mounted orchids are not likely to thrive for the windowsill grower who lives in a temperate climate, but after I added a good humidifier to my sunroom a few years ago, my own trepidation vanished.
CHOICES Whether you call them mounts, rafts, plaques or slabs, the goal is simply to find a material on which your orchid will make itself at home. Many different materials can be used. The most commonly employed are organic alternatives such as cork bark, tree fern, driftwood, and even pieces of lumber and various sorts of tree branches or small limbs.
The preference for type of wood varies by grower and region. Cypress, grape, manzanita, cedar and teak are but a few of the kinds that are commonly used. Try to select a relatively hard wood that will not deteriorate too quickly. When choosing wood, make sure any lumber used is untreated, as chemically treated wood can harm orchids. Other materials on which orchids can be successfully grown without a growing medium include porous tiles and empty clay pots, as well as wooden orchid baskets and rafts.
Part of the challenge is not only matching the orchid to a mount of the most suitable material, but also gauging its proper size. You do not want a mount that the orchid outgrows too quickly, yet too large is equally undesirable, if only for considerations of space. Knowing the mature size of the plant, plus observations of its annual rate of growth, can guide you. When in doubt, it is probably better to err on the side of smallness. Orchid roots seem to grow happily intertwined and across one another without ill effects.
Many types of orchids thrive with this kind of culture. Certainly growers who favor miniature and species orchids know that mounting is often a near necessity. Among my own first mounted orchids were some mini-catts that always seemed to possess a preponderance of rotten roots at repotting time, no matter what I did to try to keep the medium well aerated. The same was true for some of my oncidium hybrids and intergenerics. I also have some dendrobium orchids that seem to be happier with life outside a pot and I have even tried the technique with a keiki from a species phalaenopsis with surprising success.
The majority of orchids in my collection that are grown in this way are on mounts of cork bark or tree fern that range in size from about 4 × 6 inches (10 × 15 cm) to perhaps 6 × 10 inches (10 × 25 cm). I know one commercial grower that specializes in Brassavola nodosa hybrids, many of which thrive on tree-fern poles about two inches square and nine inches long, and I have begun to emulate that growing style too. I have not tried mounting orchids of very large stature, and think that, in most cases, this technique is better suited for small- to medium-sized plants.
HOW TO There is not much magic to the process. As with orchid repotting, your success in mounting orchids is more likely guaranteed if you choose that time when the orchid has new roots emerging and actively growing. After deciding on a plant and selecting a suitable mount for it, carefully extract the plant from the pot and clean the root mass of all growing medium. Soaking the roots for a few minutes in lukewarm water can greatly facilitate the ease of this process. Although it can be tedious, I try to save every root possible — taking sufficient time to do an exacting job is one of the few luxuries the hobbyist can enjoy over the average commercial grower.
Determine where on the slab you want to place the plant. Generally, you will want it toward the lower part of the mount, but a bit up from the bottom edge. Be sure to note the growing point(s) of the plant and situate them so that they will maximize their opportunity to grow up or along the mount with each succeeding growth.
Once you have the plant positioned, all that is necessary is to secure it; the usual recommendation is to accomplish this with some type of flexible wire or fishing line. The trick is to tie the plant securely to its new home without cutting or bruising its roots. You will need to wrap the line at least several times around the plant and mount to get the entire plant and its root system into proximity to the mount.
Many books and growers recom-mend that a pillow of long-fiber sphagnum be tucked under the plant before it is tied to the mount. I have not found this necessary. Perhaps this is in part due to the material I favor for lashing the plant and mount together.
For gently but firmly holding orchid plants against their new mounts, nothing beats strips of fine nylon mesh that one can produce by cutting up old (or new) pantyhose. This idea came to me in reading an article in one of our old orchid society newsletters that was written by a member whose time in the organization was well before mine.
She advised starting at the toe of the stocking and cutting a continuous, spiraling strip. It is a bit difficult because you have to stretch the material as you cut, plus the more length you cut, the more twisted the stocking becomes. I cut strips that are about one third to one half inch wide when the material is stretched between my fingers. If you are adept at cutting long pieces, they may be rolled into balls for future use, much like yarn.
The inconvenience of cutting the nylon strips is more than compensated for by the ease with which they can be pulled and stretched over the roots and spaces between orchid leaves and pseudobulbs. It does not take much practice to be able to secure the plant firmly and without injury. The nylon is long lasting and becomes almost invisible on many types of mounts. It has the wonderful ability to stretch with the roots as they grow and I’ve even been able to gently tuck new roots under the strips as they emerge. The nylon strips are also excellent for tying plants to tree branches in those climates where orchids can be nat-uralized outdoors.
CARE OF PLANTS Mounted orchids certainly require more frequent watering than their potted coun-terparts; some need watering daily, at least during the warmer season. Fertilizing is most easily accomplished by spraying the roots of the mounted plants with a water-soluble fertilizer after they have been watered. Still, one needs to watch that the plants are not kept so damp that excessive green algae or moss develops.
While most hobbyists tend to grow their mounted orchids rather vertically, it is important to realize that, in nature, most orchids grow on horizontal branches and limbs. You may discover that some types thrive better when allowed to develop on a recumbent slab.
I have found that most of my mounted orchids send their new roots onto their new homes hungrily, and I can often cut the ties holding them to the mount after just a few months. It seems to me that old roots tend to branch more readily on mounted plants, but that is hard to verify.
Mounted plants can often stay on the same perch for many years; in fact, I have seen examples of mounted orchids in some collections that have created a tangle of roots so dense that the mass supports the plant long after the original mount has decayed. If you overcome your fears and have the correct environment, mounts provide perhaps the best way to grow and enjoy healthy orchids.