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Cattleya Alliance
by Ned Nash
At the dawn of modern orchid culture in the mid-19th century, the chance discovery of Cattleya labiata in a shipment of plants from an unknown area of Brazil set the horticultural world on fire, and excitement about "the queen of orchids" continues to this day with the significant horticultural achievements being made in Taiwan. No other group of orchids comes in the fantastic range of colors and sizes as the Cattleya Alliance. Cattleya amethystoglossa and C. guttata can reach over six feet, while the dwarf varieties of Laelia and Sophronitis can comfortably fit into a teacup. The flowers of the largest modern hybrids can reach well over eight inches in diameter, and the range of miniature hybrids—with two- to three-inch flowers that often exceed the size of the plant—just keeps expanding.
Gardeners in frost-free climates may be able to grow hybrids of Laelia anceps outdoors, as the plants are tolerant of near-freezing temperatures.
Cattleyas beckon with a dazzling palette: whites, with yellow throats or red lips; countless shades of lavender, most with darker lips; yellows ranging from pastel lemon to the most intense gold, many with contrasting red lips veined in gold; all kinds of reds, oranges, and salmon hues; party-colored splash petals with a mixture of tones that can include shades of green and bronze, in some cases even near blue. Beyond the wide range of colors, many cattleyas tempt with fascinating shapes and tantalizing fragrances. Hybridizing has truly reached a pinnacle of creativity, and today's enthusiasts are its beneficiaries.
Unfortunately, cattleyas are not as widely grown now as in past years. Many of the most famous Cattleya breeders have retired or otherwise exited the business, leaving only a few to carry the torch, often with a very focused purpose. Some of the best modern standard cattleyas come from Taiwan. For a good selection of reasonably priced plants from respected growers, you may visit just about any orchid show. Be aware, though, that the selection will most likely originate from only a few nurseries as more and more vendors choose not to create their own hybrids, preferring instead to buy from other sources.
Cattleya Slc. California Apricot is a small plant that will thrive in a four- to five-inch pot.
In recent years hybrid Phalaenopsis have been eclipsing cattleyas in the public's mind as the prototypical orchids. Mastering the art of Cattleya culture is no longer the first challenge for budding orchid enthusiasts. From the years immediately following World War II until the early 1990s, Cattleya culture was the standard against which all other orchid culture was measured. "Grow like a Cattleya, but with less light" or "more heat" or "slightly more water" and so on were the instructions commonly given to novices.
Traditionally, cattleyas were the epitome of "intermediate" orchids. Since many aspiring orchid growers had a greenhouse of some kind, intermediate conditions (one of the three classic greenhouse temperature ranges, the others being warm, or tropical, and cool) were a great starting point. Once they had mastered cattleyas, the orchids most widely available at the time, growers had no trouble understanding how to adapt Cattleya care to other orchids. Today, however, more and more orchid growers are indoor gardeners, who can provide only a limited range of growing conditions. This is one of the reasons for the growing popularity of Phalaenopsis and other low-light orchids. Unfortunately, when beginning growers attempt to grow a Cattleya like a Phalaenopsis—particularly if in a moment of rash enthusiasm they have succumbed to the overwhelming beauty of a standard-size plant—they are doomed to failure. Nevertheless, with just a few modifications of their growing setup and a modicum of good sense, indoor gardeners can succeed very well with carefully chosen cattleyas.
Selecting the Right Size
A hybrid of Brassavola nodosa, B. Moonlight Perfume inherits its parent's heavenly scent and grows prolifically.
Proper plant selection with size and habit appropriate for the available growing environment is essential for successful Cattleya culture. For most growers, small ("minicatts") to intermediate-size ("midicatts") plants are best. Savvy breeders know this, and there is a broad array of attractive hybrids and meristems (clones) available from a good range of sources. Look for plants that branch freely and mature at no more than eight to ten inches tall, excluding the inflorescence. If you choose plants in that size range, you will be able to provide good light for them, whether you grow them under lights or on a windowsill; taller plants might not fit under your light setup or will get good light only on one side when set on a windowsill.
Most plants should mature in a four- to five-inch-pot and produce multiple inflorescences per pot. There is a good selection of parents whose progeny will fit the bill, including Cattleya Slc. California Apricot, C. Blc. Orange Nugget, C. Sc. Beaufort, and C. walkeriana. Cattleya walkeriana is a particularly good parent, as it tends to produce relatively large flowers for its size displayed on multiple inflorescences, and it also imparts a delightful perfume, all lovely qualities to pass on to its offspring. Laelia pumila and Sophronitis coccinea are two other popular parent species, though S. coccinea may need cooler temperatures than can be easily accommodated in the home.
Members of the Cattleya Alliance, such as Brassolaelia Richard Mueller x Epidendrum schumanianum, upper right, and Potinara Hoku Gem, lower left, require bright light but need to be protected against direct sun during the middle of the day.
There is also a wide array of smaller-growing plants bred from rupicolous (rock-growing) laelias that originally came from Brazil. Some of the best-known hybrids are Laelia Blc. Love Sound, L. Lc. Love Knot, and L. Sc. Cheerio, with popular parents such as L. rupestris, L. sincorana, L. briegerii, and L. milleri. These dwarf plants come in exciting shades of yellows, oranges, and reds, but they may be a little more difficult to grow, as they require careful attention to watering and resent too much water.
The "lady of the night," Brassavola nodosa, is an increasingly popular parent owing to its compact stature and exotic flower shape. It gives a heavenly scent to its progeny and grows prolifically. Species such as Cattleya loddigesii are useful not only for their relatively compact habit but for their seasonal dominance (hybrids that have a species as one of the parents will often have a very pronounced blooming season similar to that of the species). Avoid hybrids from some of the larger-growing species such as Laelia purpurata and the huge Brazilian bifoliate catts. Of course, gardeners living in frost-free areas where they may grow their plants out-of-doors for some or all of the year have a much broader selection available to them, though compact plants are always desirable, no matter where you grow your orchids. Gardeners in areas where cymbidiums thrive out-of-doors year-round should not overlook hybrids from the Mexican Laelia anceps, which gives progeny tolerance for near-freezing temperatures and produces flowers that closely resemble standard, classic catts.
Cattleya Seedlings and Meristem Plantlets
Commercial growers who sell at orchid shows will often have actual samples or pictures of the plants they are offering. If you are purchasing a meristem plant, you are getting a clone that will be exactly like the sample or picture. If a seedling is your choice, remember that the sample is only an approximation of what you are likely to get. Hybrids are like children; they will be similar but not identical. Which is better for you? It depends on your gambling instinct. If you like the idea of possibly getting something superior, seedlings are for you; if you absolutely must know exactly what your plant is going to look like, purchase only meristems. Whether or not the meristem plants are significantly more expensive than the seedlings depends for the most part on the grower, but you can expect to pay a slight premium for having the guesswork taken out of the process.
Tips for Growing Cattleyas
Light
Whether in a greenhouse or in the home, the most important factor in growing cattleyas is light. The plants need bright light to some sun, with no direct sun in the middle of the day. Place them in an east, shaded south (as with a sheer curtain), or west window in the home, and at 40 to 60 percent full sun in a greenhouse (2,000 to 3,000 foot-candles). Leaves should be a medium green color, pseudobulbs erect and requiring no staking.
Cattleyas and their relatives come in all sizes. Diminutive Laelia pumila, above, easily fits under lights or on a windowsill. Cattleya walkeriana, below, is an intermediate size.
Temperatures
At night, temperatures should be 55°F to 60°F and during the day 70°F to 85°F. Seedlings should have night temperatures five to ten degrees higher. A 15- to 20-degree temperature difference between day and night is best, especially for mature plants. Provided that humidity, air circulation, and shading are increased, plants can tolerate higher day-time temperatures of up to 95°F.
Water
Many factors, such as type of container, temperature, and light determine how much water is required. Seedlings need constant moisture, but mature cattleyas need to dry out thoroughly before they receive water again. If in doubt, compare the weight of a dry pot of the same size and type of mix with a wet pot—light means dry, heavy means wet. If you're still unsure, wait a day or two before watering again. Plants in active growth need more water than plants that are resting. Water below 50°F may injure plants, as will water softened by the addition of salts.
Humidity
Cattleyas require 50 to 80 percent humidity. In the home, place the plants on trays of gravel partially filled with water, making sure that the plants do not sit in the water. Air should always be moving around the plants to prevent fungal or bacterial diseases, especially in the presence of high humidity or cool temperatures. In the greenhouse, it's best to use a humidifier to increase humidity. Evaporative cooling increases humidity while cooling the air.
Fertilizing
Use a high-nitrogen fertilizer such as 30-10-10 or a similar formulation when growing the plants in fir bark. Otherwise use a balanced fertilizer such as 20-20-20. When in active growth, plants need fertilizer at least every two weeks; when they are not actively growing, once a month is enough. Or apply fertilizer with every watering at one quarter the recommended strength. To prevent the buildup of fertilizer salts, thoroughly flush the plants with clear water every month.
Potting
When the rhizome of the plant protrudes over the edge of the pot or the potting medium starts to break down and drain poorly (usually after two to three years), it's time to repot. Do this just before new roots sprout from the rhizome, after flowering, or in the spring. Mature cattleyas are usually potted in coarser potting material than seedlings. Until a plant has at least six mature pseudobulbs, move it to a larger pot rather than divide it. When you divide a plant, you should have three to five pseudobulbs per division. Select a pot that will allow for approximately two years of growth before crowding the pot. Pile mix against one side of the pot and cut off any dead roots. Spread the firm, live roots over the pile, with the cut rhizome against the side of the pot. Fill the pot with medium, working it in around the roots. Pack firmly and stake if necessary. Keep the plant humid, shaded, and dry at the roots until you see new root growth.
—American Orchid Society
Ned Nash has been an "orchid guy" all his professional life. He is a well-known and widely respected judge for the American Orchid Society, and most recently, he has been director of Education and Conservation for the AOS. He recently moved back to California to join Cal-Orchid, Inc.
Photos: Charles Marden Fitch