How to Grow: Cattleya Orchid Care
Orchid enthusiasts collect different hybrids with Cattleya as one of the more popular varieties. It is native to tropical America and sometimes referred to as the “queen of the orchids.” Cattleya orchid plants produce some of the brightest, most uniquely formed flowers in the orchid world. The average home interior is perfect for growing Cattleya orchids. There are just a few details to learn regarding how to grow Cattleya orchids; but once you master those, you will have a lovely and long-term addition to your home.
The orchid plants we call “cattleyas” may be species or hybrids within the genus Cattleya, or they may be close relatives (Laelia, Brassavola, Sophronitis, Epidendrum, Encyclia, Broughtonia), or hybrids among these genera. Fortunately most of the species and hybrids of the cattleya tribe are easy to grow, and some are highly recommended for beginners’ collections. Many of them adapt beautifully to our subtropical conditions, doing equally well in pots and other containers, or naturalized in our trees.
Some interesting information about Cattleya is their native habit as Epiphytes, or tree growing plants. They can cling to a tree crotch or rocky crevasse and need little soil. The plants are long lived perennials and some professional collectors have plants half a century old. Cattleya orchid plants grow well in soilless media, such as bark and rocks or perlite, which mimics this natural growth habit. The thickened stems, called pseudobulbs, store moisture for the plant to use during the dry season.
Like most flowering plants, cattleyas want bright light in order to grow and flower well. They will take fairly high light levels early and late in the day, but should be protected from direct midday sunlight. You can easily tell if a cattleya is getting the right amount of light by looking at the foliage. Afternoon sunlight coming through west-facing windows can be extremely hot and, without adequate air movement and humidity, damaging to your plants.
If the plant’s leaves are rich, dark green, it isn’t getting enough light; if the plant is light yellow-green, it’s getting too much light. The correct light levels produce foliage with an attractive medium green color. If your cattleyas don’t flower, lack of light may be the culprit, but don’t move plants abruptly from too-shady to very bright conditions. Move the plant gradually to brighter conditions or you may scorch the foliage. Some species in the cattleya alliance grow in nearly full sun in their native habitats, although most of the commonly cultivated species and hybrids prefer just slightly shadier conditions than this. Let the foliage color be your guide to the amount of light necessary for good growth and flowering. As a general guide, cattleyas want very bright shade, with some sunlight early or late in the day.
Although Cattleyas come from the tropics where the sunlight is hot and intense, most species are found at fairly high altitudes where the air is cool and moist, particularly in the morning and at night.
The temperature requirements for Cattleyas are daytime temperatures somewhere between 21°C to 27°C and night temperatures between 12.8°C to 15.6°C. Higher daytime temperatures encourage faster growth, although if you plan to keep your orchid in higher temperatures you will have to remember to maintain higher humidity conditions, more air movement, as well as more frequent waterings.
Improper watering, both under- and over-, leads to the death of Cattleyas, than any other single cause. There are two aspects of proper watering to consider: when and how. Simply summarized, cattleyas should be watered only after the potting medium has become “dry.” Frequency of watering will vary. Once a week is a good base to begin, remembering that some factors will speed up drying of the potting medium, others will slow it down.
A lot of sunshine, heat, good air movement, active growth, a large plant in a small pot, low humidity, the type of potting medium (such as bark, gravel, tree fern chunks, etc.), windy weather and the like all contribute to faster drying and, consequently, increased frequency of water. Conversely, high humidity, dark, cold, cloudy or rainy weather, large pots, inactive plants (that is, not in active growth), tightly packed potting medium, little air movement and similar circumstances will slow the process of drying and hence decrease the frequency of watering.
Note that some of these factors affect the entire collection of plants, other affect only certain individual plants. Watch each plant carefully, consider each by itself. Each beginner must learn for themselves, but remember that plants will recover much more rapidly from under-watering and it is best to err on the dry side, following the rule, when in doubt, don't water.
Do not soak their plants in a bucket of water. Should one of the plants have a disease or insect infestation, all those soaked in the same water after it may well become infected.
Cattleyas do best when humidity ranges from 50% to 80%. Therefore, except in areas where natural humidity is quite high, or during cold, cloudy or rainy weather, it is important to add moisture to the growing environment, especially during the day. This can be accomplished in a number of ways.
Using a Humidity Tray is one of the best ways. These trays are nothing more than a water-holding tray filled with gravel. The gravel-filled trays are filled with water to a level just below the surface. To prevent plants sitting on constantly wet gravel the plants are placed on small saucers or pieces of plastic or metal grid placed on top of the trays. A plump lead pseudobulb indicates a well-hydrated plant.
In the greenhouse, the humidity is best increased by use of a humidifier. Where natural humidity is high or where humidification maintains a high degree of humidity, increased air movement is essential to prevent stagnant air and the development of diseases. Good ventilation or the use of fans is recommended.
Most cattleya orchids produce one new flush of growth annually, and each new pseudobulb should produce flowers the same growing season, often in late summer or winter. Some of the hybrids might produce two blooms annually. Depending on the species, they may produce just a few blossoms or bunches of smaller, waxy flowers. New flower buds are protected by a thin sheath that emerges from the center of the leaf. If Cattleyas don't re-bloom, it's generally a light level issue.
Most species cattleyas have relatively distinct growing and resting phases during the annual cycle. While the plants are actively growing, they should be fed and watered regularly. We fertilize weekly during the growing season, and cut back on both fertilizer and water during the shorter, cooler days in winter. Hybrids in this group, however, may or may not show a distinct growing/resting pattern. Some do stop growing and rest in the winter, some do not. Learn to recognize the signs of growth and the signs of resting, and care for your plants according to their needs during these parts of the cycle. The resting phase may last a few weeks or a few months.
In “captivity”, cattleyas do best with supplemental fertilizing. The best fertilizer depends on the potting medium you use. For mostly inert potting materials ( Coconut Husk, Charcoal, lava rock, perlite), we recommend a balanced fertilizer with micronutrients. Overfeeding, in cattleyas, can lead to loss of roots and consequent death of the plant. To a lesser degree, when feeding a well-rooted plant, overfeeding can result in the production of vegetative growth instead of flowers, sometimes resulting in blind sheaths. In feeding, it is better to err on the side of too little than on the side of too much.
Balanced Fertilizer for Growth: 20-20-20 (NPK) – 2 grams per litre of water – Spray once in every alternative weeks (14 Days)
High-Phosphorus Fertilizer for Blooming: 0-52-34 (MPK) – 1 gram per litre of water – Spray on every alternative weeks (14 Days)
Potting , Media and Propagation
Potting is necessary when the rhizome of the plants protrudes over the edge of the pot or the potting medium starts to break down and drain poorly. Before repotting in a new pot, you should always trim away the damaged roots with a sterile cutting tool. The most common potting media are still based more or less on chopped fir bark although more open media like charcoal, coconut husk or inorganic media like expanded clay pellets and lava rock may be a better choices in very humid hot areas of the country. The choice is predominantly a personal one and based on whatever gives good results for the grower.
To pot a Cattleya plant, it should first be cleaned of old roots, decayed medium and debris. The new potting medium should be moistened before use if possible. This is again more or less a personal choice but soaking the potting medium before use helps to reduce the amount of dust and it's easier for beginners to determine when to water when they start with moist media.
Until a plant has at least six mature pseudobulbs, it generally should be put into a larger pot and not divided. If dividing a plant, three to five pseudobulbs per division are required. Select a pot that will allow for approximately two years of growth before crowding the pot. Cattleyas can be divided once the orchid has bloomed and new growth is starting to show. Each division needs at least four growths in order to do well on its own. After dividing the orchid it is imperative to keep the plants in a humid area while to roots begin to grow.
“ As Adaptable, there is no Single Best Potting Medium”
Pests and Other Cattleya Related Problems
Fungal and Bacterial Diseases of Cattleyas are common because of the high levels of humidity they need to survive. Fungal agents cause problems like root rot, leaf spots, leaf blights and spots on flowers.