General Information
Orchid enthusiasts collect a variety of hybrids, with the Cattleya being one of the most popular varieties. It is native to tropical America and is sometimes referred to as the “queen of orchids.” Cattleya orchid plants produce some of the most vibrant and uniquely shaped blooms in the orchid world. There are only a few details to learn about how to grow Cattleya orchids; but once learned, you will have a beautiful, long-lasting 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 between these genera. Fortunately most of the species and hybrids in the Cattleya tribe are easy to grow and some are highly recommended for beginner collections. Many of them adapt beautifully to our subtropical conditions, growing equally well in pots and other containers, or naturalized in our trees.
Some interesting facts about Cattleyas include their native epiphytic habit, meaning they are tree-dwelling plants. They can cling to a tree branch or a rock crevice and require little soil. They are long-lived perennials, and some professional collectors own specimens that are half a century old. Cattleya orchid plants grow well in soilless mediums, such as bark and rocks or perlite, which mimic this natural growth habit. Thickened stems, called pseudobulbs , store moisture that the plant can use during the dry season. Let's delve into the care of Cattleya orchids.
Light
Like most flowering plants, Cattleyas need bright light to grow and flower best. They require rather high light levels in the early morning and late afternoon, but you should protect them from direct midday sunlight. It is easy to tell if a Cattleya is getting the right amount of light by looking at its foliage. Afternoon sun filtering through west-facing windows can be extremely hot and, without adequate air movement and humidity, can damage plants.
If the plant’s leaves are a rich, dark green, it is not receiving enough light; if the plant is a pale yellow-green, it is receiving too much light. The proper light levels will result in attractive, medium green foliage. If your Cattleyas are not flowering, lack of light may be the cause, but do not suddenly move plants from very shady conditions to very bright light. Gradually move the plant to brighter conditions, or you may burn the foliage. Some species in the Cattleya family grow in almost full sun in their native habitats, though most commonly grown species and hybrids prefer somewhat shadier conditions. Let the color of the foliage be your guide to the amount of light needed for good growth and flowering. In general, Cattleyas like bright light, with some direct sun either early or late in the day.
Temperature
While Cattleyas are from the tropics, where the sun is warm and intense, most species are found at rather high altitudes, where the air is cool and moist, especially in the morning and at night.
The required temperatures for Cattleyas are between 70 and 80 degrees F during the day and between 55 and 60 degrees F at night. Higher daytime temperatures result in faster growth, but if you plan to grow the orchid in higher temperature regions, you need to maintain a higher humidity level, more air movement, and more frequent watering.
Watering
Improper watering, either too little or too much, leads to the demise of Cattleyas more than any other cause. There are two things to consider for proper watering: when and how. In summary, Cattleyas should only be watered after the potting medium has "dried out." The frequency of watering varies. Once a week is a good starting point, bearing in mind that some factors accelerate the drying of the potting medium, while others slow it down.
Plenty of sunlight, warmth, good air circulation, active growth, a large plant in a small pot, low humidity, the type of potting medium used (such as bark, gravel, tree fern fragments, etc.), windy weather, and the like all contribute to faster drying and, consequently, more frequent watering. Conversely, high humidity, dark, cold, cloudy or rainy weather, large pots, inactive plants (i.e., not actively growing), overly compact potting medium, poor air circulation, and similar circumstances will slow down the drying process and thus reduce the frequency of watering.
Keep in mind that some of these factors affect the entire plant collection, while others only affect individual plants. Observe each plant carefully, considering it individually. Every beginner must learn for themselves, but remember that plants will recover much more quickly from a lack of water, and it's better to err on the side of underwatering, following the rule "when in doubt, don't water."
Humidity
Cattleyas thrive best when humidity ranges from 50% to 80%. Therefore, except in areas where natural humidity is quite high, or during cold, cloudy, or rainy days, it's important to add humidity to the growing environment, especially during the day. This can be done in several ways.
Using a humidity tray is one of the best methods. These trays are nothing more than a water container filled with gravel. Gravel-filled trays are filled with water to a level just below the surface. To prevent plants from sitting in constantly wet gravel, plants are placed on small saucers or pieces of plastic or wire mesh positioned above the trays. A full, plump pseudobulb indicates a well-hydrated plant.
In a greenhouse, humidity is best increased using 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.
Flowering
Most Cattleya orchids produce one new flush of blooms per year, and each new pseudobulb should produce flowers in the same growing season, often late summer or winter. Some hybrids may produce two flushes of blooms per year. Depending on the species, they may produce only a few flowers or clusters of smaller, waxy flowers. New buds are protected by a thin sheath that emerges from the center of the leaf. If your Cattleyas are not reblooming, it is generally a light problem.
Growth Cycle
Most Cattleya species exhibit relatively distinct growth and rest phases during the annual cycle. During active growth, plants should be regularly fertilized and watered. We fertilize weekly during the growing season and reduce both fertilizer and water during shorter, cooler days in winter. Hybrids in this group, however, may or may not show a distinct growth/rest pattern. Some stop growing and go dormant in winter, others do not. Learn to recognize the signs of growth and rest, and care for your plants according to their needs during these phases of the cycle. The rest phase can last a few weeks or a few months.
Fertilizer
In "captivity," Cattleyas do best with supplemental fertilization. The best fertilizer depends on the potting medium used. For predominantly inert potting materials (coconut husk, charcoal, lava rock, perlite), we recommend a balanced fertilizer with micronutrients. Over-fertilization, in Cattleyas, can lead to root loss and subsequent plant death. To a lesser extent, when fertilizing a well-rooted plant, over-fertilization can lead to the production of vegetative growth rather than flowers, resulting in stunted sheaths. When it comes to fertilizing, it's better to err on the side of less than more.
Recommended fertilizers:
- Balanced fertilizer for growth: 20-20-20 (NPK) – 2 grams per liter of water – Spray once every two weeks (14 days)
- High phosphorus fertilizer for flowering: 0-52-34 (MPK) – 1 gram per liter of water – Spray every two weeks (14 days)
Repotting, Substrates, and Propagation
Repotting is necessary when the plant's rhizome extends beyond the edge of the pot or when the potting medium begins to deteriorate and drain poorly. Before repotting into a new pot, it is always advisable to cut off damaged roots with a sterile cutting tool. The most common substrates are still based on shredded fir bark, although more open substrates such as charcoal, coconut husks, or inorganic substrates like expanded clay pellets and lava rock may be a better choice in hot, humid areas of the country. The choice is predominantly personal and based on what yields good results for the grower.
To repot a Cattleya, you must first clean it of old roots, rotten potting mix, and debris. The new potting mix, if possible, should be moistened before use. This is also more or less a personal choice, but soaking the potting mix before use helps to reduce dust and is easier for beginners to know when to water when starting with a moist mix.
As long as a plant has at least six mature pseudobulbs, it should generally be potted into a larger pot and not divided. If dividing a plant, three to five pseudobulbs are needed per division. Choose a pot that allows about two years of growth before filling the pot. Cattleyas can be divided once the orchid has flowered and new shoots begin to appear. Each division needs at least four shoots to grow well on its own. After dividing the orchid, it is critical to keep the plants in a humid area while the roots begin to grow.
Pests and Other Cattleya-Related Problems
Fungal and bacterial diseases in Cattleyas are common due to the high humidity levels they require to survive. Fungal agents cause problems such as root rot, leaf spots, leaf blights, and flower spots.
