A Basic Guide to Home Orchid Culture
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Venger's Orchids 1220 Pando Avenue Colorado Springs, CO. 80906 (719) 576-7686
Light: Lighting requirements for Orchids will vary according to the genera that the plant belongs to, and in some cases, according to the specific species or hybrid within a genera. Altitude also is a factor. Here in Colorado Springs, where our elevation is above 6000', direct sun will quickly damage or kill an Orchid, whereas at sea level, many Orchids not only tolerate, but thrive in it. Giving your Orchids the correct lighting is one step to insuring that it will not only enjoy a long life, but will bloom for you as intended. Overall, give your Orchid as much light as it will tolerate without burning the leaves. Though there are exceptions, the amount of light and how your plant is tolerating it is fairly easily judged by the color of the foliage. Dark green leaves on a Cattleya, for instance, is evidence that the plant is not receiving enough light. Bright Yellow signifies that the plant has reached it’s level of tolerance, and the amount of light the plant is getting should be reduced. Light to medium-green would be ideal. Bear in mind here that reddened foliage is damaged beyond repair and will die. South facing windows, for windowsill culture, is probably best, though some screening, or sheer curtains, may be necessary. West, East, and North facing windows are acceptable, in that order of decreasing preference, though some Orchids will prefer one over the others. We generally prefer to give our Orchids 14 hours of light per day, regardless of season, which requires some amount of artificial lighting, in the form of fluorescent ‘Gro-Lights’, especially during the winter months.
Humidity and Air Movement: Unlike warm-blooded animals, Orchids, like all plants, have no way to regulate their internal temperature. In an Orchid's environment, humidity in combination with moving air is one way that nature accomplishes this. If you take rubbing alcohol and apply it to your skin, it feels cool because it evaporates rapidly. In the same way, humidity in the air cools an Orchid, and prevents it from becoming dehydrated by transpiring it's own moisture into dry air. Generally, humidity around your Orchids should be in the 40-70% range. Air movement around the plants will also help prevent fungi from the moist air from gaining a foot-hold on your plant. Overall, as the temperature around your plant rises, so should the humidity. If you aren't growing in a greenhouse, plastic saucers filled with wet gravel will provide humidity to your Orchids. Be certain that no water is coming into the bottom of the pot, as this will cause root-rot, and a swift demise of your expensive plants! Supplemental spraying with water in a spray bottle will also help to cool your plants on hot days. A small fan will facilitate air movement nicely.
Temperature: Orchid culture, from a temperature viewpoint, is generally divided into 3 sections: Cool growing, Intermediate, and Warm. These temperature ranges are at times expressed in terms of minimum night-time temps. Cool growing Orchids easily tolerate temps down into the 50's, and at times, 40's. Intermediate growing Orchids generally enjoy temps over a 24 hour period of 65-85 deg f. , while warm growers prefer nighttime temps above 70. I emphasized intermediate Orchids as they generally are most popular in this section of the country, due to hot, dry summers and cold winters. While intermediates will tolerate both lower and higher temps, it must be noted that as the temperature gets below 60 deg, or above 85, plant growth slows. Temps above 90 will actually stop growth in many cases, and while this may not actually harm the plant, neither does it do it any good. Conversely, dropping the night-time temperature of some Orchids will help to induce blooming, as will be discussed later. Temperature variation from night-time to day- time should be at least 10 deg f. If you've referred back to the section on Humidity and concluded that Orchids like to be somewhat warm and wet, you're correct, though there are at times wide variations as to preferences.
Nutrition: If there is one area where an Orchid will invariably suffer at the hands of a begginer, this is it. Imagine if you will, how well you might fare if you were kept on a diet of only water, and with inconsistent feedings at that. Probably not very well, nor for very long. If there is one thing that an Orchid appreciates, it’s consistency. That doesn’t mean you have to give up your vacations, only that Orchids require a certain level of care to remain at their peak. A calendar is very useful for roughly outlining what you will be doing and when, especially when your collection grows. Changes can be made according to changes in the weather, ie, if the temperature rises for a few days, watering may be necessary a day or so earlier than you had scheduled. Generally, the potting mix should not completely dry out. Conversely, it should not stay wet either. I generally recommend that you not water more often than every 4 days, but at least every 7 days. Every 5 - 6 days is generally appropriate, though there are exceptions. Feeding your Orchid is every bit as important as watering, and for best results, require two or more kinds of fertilizers. As a minimum, I suggest 20-20- 20 for growth, and 10-30-20 to induce blooming. For those of you not familiar with fertilizers, the 1st number in the above formulas represents the percentage of available Nitrogen (for growth), the 2nd, Phosphorus (for blooming) and 3rd, Potash, (for root health). See graphic é. Increasing one while decreasing others fine tunes your feedings to emphasize what you want your Orchid to do, at least to some extent. Trying to induce blooming constantly in an Orchid that blooms only once per year will yield disappointing results. As a general rule, I use 10- 30-20 to steer an Orchid in the correct direction. It is very difficult to force an Orchid into bloom, and in any case is not recommended. Fertilizers are generally used at a rate of 1/2 the recommended strength stated on the label. In addition, most readily available fertilizers do not contain micronutrients (mineral elements) that are necessary to an Orchid’s health. While an Orchid will, for a time do fairly well without them, eventually the deficiency will manifest itself in fewer, smaller or no blooms, and a decrease in the overall health of the plant. (Venger’s Orchids has both 20-20-20 and 7-7-7 with micronutrients for sale) As for feeding schedules, Feed with 20-20-20 for 3 straight waterings, followed by 10-30-20 the next time, if appropriate, and lastly, flush with straight water for the final watering of the cycle. Flushing in this manner leaches out some of the leftover chemicals from the previous 4 feedings. Any additional fertilizers can be worked into the schedule easily.
Again, your Orchid will appreciate consistency. Overwatering is very liable to result in root rot, which causes a paradoxical problem of dehydration. In this situation, the problem might start out with you noticing your phalaenopsis leaves beginning to shrivel a bit, feel rubbery and limp. As this is a symptom of dehydration, you immediately water your phal and adjust your schedule to compensate. The mistake made here was that the potting medium and roots were not checked initially to see if dehydration from underwatering was truly the problem. Overwatering causes the Vellum, or outer covering of the roots to disintegrate and literally rot away. Visually this is confirmed by unpotting the plant and observing that the roots are black and falling apart at a touch. You would also see the inner portion of the root, which is thin and wire-like. The destruction of the Vellum makes the Orchid incapable of water or nutrient intake and the plant initially dehydrates. Prompt diagnosis and treatment in the form of repotting is necessary to save the plant! Dehydration not caused by root rot is another problem and one that in many cases can be solved by altering your watering schedule or becoming a bit more consistent. Symptoms vary according to different genera. Phalaenopsis in dehydration will appear as described above. Brassias and Oncidiums may exhibit premature wrinkling of the pseudobulbs as the plant attempts to keep itself hydrated. The most common symptom will be crinkling of new leaves, taking on an accordion look. Neither symptom can be ‘cured’ though the problem can be solved with adjustments to the watering schedule or temperature. In Cattleyas, dehydration will manifest itself in shriveled pseudobulbs and leaves that take on a dessicated or dry look. Again once these symptoms have appeared, those pseudobulbs and leaves will keep that appearance for life. If you are a beginner, or simply don’t have the knowledge or facilities to properly diagnose and solve these problems, please call us immediately. We will diagnose the problem and give the proper advice. If your plant is suffering from root rot, we can repot into new media. There may be a small charge for some plants. Over-fertilizing is another nutritional problem under the heading of “Too Much Of A Good Thing”. Unless you really over-do it, over fertilizing usually won’t jeopardize your Orchid. It will however make it unsightly. The first and foremost symptom is burning of the leaf tips, as this is generally the thinnest part of the plant. Keep your fertilizer’s nitrogen level at or below 20% and adjust the amount of fertilizer you use. If you are following the “1/2 the recommended strength stated on the label” as mentioned above, you should not have any problems. Don't try and force your Orchid to grow.
Editorial time: Somewhere along the line you've undoubtedly heard that Orchids are "Hard to grow". There are two main reasons. One is that the buyer simply doesn't know what to do with this ordinary looking plant with the outrageous looking flowers, and the seller too often is not knowledgeable enough in a practical sense to educate the buyer properly. Nurseries and flower shops tend to fall into this category, though there are exceptions. The other reason is Orchid growers that sell their plants to resellers in potting mixes that are inappropriate. One example of this is a California grower that specializes in Phalaenopsis and sells his plants to nurseries potted in peat moss. For him, peat moss is probably ideal. His greenhouses are completely computerized to keep track of temperature, humidity and watering schedules, and alters the conditions and schedules as needed, all automatically. For the beginner, this is nothing more than a disaster that hasn’t happened yet. Which brings us back to reality.
For the most part, potting mixes are of various coarseness, from fine to very coarse, and can have a variety of ingredients, some of which make sense, and some of which don't. Some common ingredients are Redwood bark, Firbark, Sphagnum, New Zealand Sphagnum, Osmunda Fiber, Tree Fern, Charcoal, Perlite, Gravel, etc. In theory, you could grow an orchid in marbles. The potting mix should provide at least two things. Something to hold moisture for a certain amount of time, such as redwood bark, and something to provide drainage to avoid root rot, such as perlite. Many growers, including ourselves, add white styrofoam peanuts to the bottom of the pot. It adds drainage, doesn't decompose, and stays out of the landfill. Charcoal can be added to the mix to regulate acidity from the decomposition of any organic materials used. We favor a mix of medium Redwood bark, Charcoal and Perlite, mixed 2-1-1 for most Orchids past the 2 1/2” (pot size) stage. For seedlings we use fine Redwood bark and fine perlite, as the seedlings are less prone to root-rot and this mix will retain more water. Some genera, such as Masdevallia, Paphiopedilum and Odontoglossum, to name a few, stay in the fine mix even as adults. As for pots, we prefer plastic Azalea pots except for certain Orchids where we must tightly regulate moisture, or in Orchids where the pot size is 10” or larger. In these cases we use standard unpainted red clay pots, as these will draw excess moisture out. Repotting is generally done every two years and serves two purposes. One is to replace partially decomposed bark which holds more water than is wanted and has less drainage capabilities, and the other is to give the Orchid growing room. We generally advise repotting into the smallest size possible, allowing for two notable exceptions are Dendrobiums and Oncidiums, which like to be pot bound. I do not advise repotting simply to control root growth for two reasons. One is that it’s simply more ‘natural’ looking to have roots flowing out of the pot or basket, and secondly, if your conditions will support them, the extra roots are able to tap the humidity, possibly avoiding dehydration problems if you forget to water occasionally. Repotting should be done when new growth is just beginning if possible. Be aware that any new roots, when over 1” long, are subject to breaking and care must be taken not to damage them. The process of repotting is fairly straightforward, though a bit unnerving to the beginner. First make sure you have your pot (either new or sterilized with bleach and rinsed) and mix ready. Sift the new mix prior to repotting to remove dust particles that might clog the roots. You’ll also need a pair of scissors, preferably sterilized with a propane torch. If a torch is not available, soak the blades in alcohol or Betadine (Povidone-Iodine) for 10 minutes. (This sterilization should be repeated before using the scissors on any other Orchid to prevent the spread of any harmful organisms from one Orchid to another) With everything ready, unpot your Orchid. If clay, the pot may have to be broken with a hammer, hitting just hard enough to crack the pot. If plastic, hold the orchid firmly just above the level of the mix and upend it. A gentle tug may pull the Orchid free. If not, try tapping the edge of the pot on a hard surface or gently squeezing the pot to free the roots. That finished, begin gently pulling the old mix away from the roots. Pay special attention to the area directly under the plant and be sure to remove as much material as possible. Examine the roots and cut away any that are black and rotted or no longer have the Vellum attached. This is also a good time to look for and remove any bugs, slugs or snails. When finished begin repotting. If you have any white (not colored) styrofoam peanuts you can put some in the bottom to a depth of approximately 1”. Insert the plant into the pot and gauge it’s depth. The crown of the roots should be at the level of the sub-rim of the pot, usually about 1 1/2” below the rim. Add enough potting mix under the plant to bring the Orchid to the proper level. Place the Orchid in the pot so the new growth is approximately in the center in the pot. If the Orchid has new growth in two or more directions, then center the plant. While holding the plant, begin adding the new mix around the roots in 1” layers, firmly compacting each layer with your thumb, and continuing until the base of the plant is just covered. Compact one last time and you’re finished. The Orchid should be tight in the mix with little or no wobble. If it does wobble, repot it again until it doesn’t. In some plants, where a large part of the root system has had to be cut away, you may have to stake the plant in position with a bamboo stake and twist tie. If this is the case, after you’ve placed the Orchid back in it's "home", don't move it any more than necessary for a month or so. If you've repotted a Cattleya, if at all possible, water immediately, put in a shady area and then don’t water again for 2 weeks. Return the Orchid to it's normal conditions after this time. Seedlings require repotting as well. However we recommend that you use a fine bark mix. Some seedlings will do well in New Zealand Sphagnum or a combination of the two. All in all, given a bit of practice and the proper materials, repotting is quite easy. However, if it's not your cup of tea or you don't have the time, Venger's will repot your Orchids for a nominal fee. We can give you a free lesson as well.
Mounting: While thinking about this section, it occurred to me that this is probably my favorite subject. Out of nearly every shipment of Orchids we get, especially seedlings, you can be sure that some of them get mounted either on cork slabs, natural cork bark or some piece of driftwood. This is, after all, almost as close to ‘natural’ as is practical to create. I highly recommend it to anyone. Admittedly, it does take a certain amount of dedication. Even here in our greenhouse, where humidity levels are rarely below 60%, we water ‘The Mounts’ every two days. In a home, count on watering every day, and misting perhaps twice per day. Is it worth it? You bet! Blooming a mounted specimen gives me 10 times the satisfaction of blooming a potted one. Not that it’s harder in any real sense. Just the sense of pride that comes from accomplishment through self-discipline. What types of Orchids can you mount? Almost any, though some do better than others. Masdevallias do extremely well on a vertical piece of cork, while Cattleyas don’t fair so well. Mounting Catts on a horizontal piece of driftwood seems to overcome their reluctance to thrive out of a pot. Oncidiums and Phallies do well in either orientation, as do Cadetias.(which we’ve bloomed mounted, potted, in nearly direct sun and in medium shade. Talk about adaptable!) Of course, Angraecums and Aerides prefer to be mounted. Overall, the difference in caring for a mount is one of timing. Everything must be done more often, with frequent checks for changes in the plant, especially those from dehydration. The risk of getting root- rot is minimal, and in fact, at times mounting a severely root-rotted plant is the only way to save it. Fertilizing is the same as for potted plants, except the schedule is accelerated. We fertilize every two days when we water, x 4, then flush with clear water. Our own method of watering is by drowning them. We mix our fertilizer and water and dunk the entire plant for 30 seconds or so and gently blow any water out of the crowns. Since we have 100+ mounts, this takes some time, but is much better than trying to soak the Sphagnum with a spray bottle, both for us and the Orchids. While mounting an Orchid is easy enough, it really requires 3 hands, not to mention an old shirt. We make do with two hands, unfortunately. The materials needed for mounting are an Orchid, the mounting material itself (we’ll assume natural cork bark), Long fibered New Zealand Sphagnum, an old pair of nylons, sterile scissors, 6 inches of wire, and optionally, one pair each of sterile forceps and needlenosed pliers. It couldn’t hurt to soak the sphagnum and the Orchid in fertilized water just before mounting. The size and shape of the cork should be appropriate to allow for growth of the Orchid, but esthetics also play a large part in your selection. After deciding where the Orchid will go on the bark, place the bark flat and lay a bed of sphagnum large enough to hold the width and height of the root ball. Place the Orchid on the sphagnum. You may want to turn it until it ‘looks right’. Gently flatten the roots down as much as possible. Insert sphagnum into any spaces between the roots, and cover the rest of the root ball. Be liberal. Don’t worry if you have a few stray roots. Next, cut a few 1/4” wide strips from the legs of the nylons, cut the loop, and tie enough together using square knots to form at least two feet of stretched material. Laying the strip under the mount and under the root, hold the strip in place with one finger along the side of the cork. Begin wrapping the nylon. You’ll need to stretch it quite a bit to create enough tension to keep the orchid in place when held upright. Wrap the nylon enough times to ensure your Orchid and the sphagnum will stay in place and tie the ends with a square knot or two. Fashion the 6 inch piece wire of into a hook and insert it into the top of the mounting material. Make sure a second hook is formed to hold the hook in place. There are other materials you can use other than nylon. Wire works, as do long pieces of twist ties, fishing line and twine. However, these materials have no stretch to them, and as the plant grows, could cut into the plant or roots.
Somewhere in between pots and mounts are baskets, usually made from cedar. Vandas, Oncidiums and Cattleyas are especially fond of basket culture. The main advantage of using baskets rather than pots is that air circulation is increased around the roots. In addition, since baskets are designed to be hung up, basket culture is a good way to increase the size of your Orchid collection. Our basket Orchids are placed in 100% Sphagnum, with white styro peanuts placed randomly around the roots to increase drainage. Watering and fertilizing is the same as for our potted specimens. The most notable observation to make here is that overall, in our experience, basket culture is easier than mounted culture, and produces healthier Orchids than potted culture. In a greenhouse environment, hanging your Cattleyas and Vandaceous Orchids is another way to create micro-environments by shading areas underneath for those Orchids that can't tolerate the higher light levels above.
Rod Venger, Venger's Orchids
venger@usa.net
Everett (Skip) Carter Phone: 831-626-3735 Taygeta Scientific Inc. FAX: 831-394-5561 100 Dolores St, Suite 186 INTERNET: skip@taygeta.com Carmel, CA. 93923 WWW: http:
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