Known as the jewels of the orchid family, the Masdevallias flourish in the cool cloud forests of Central and northern South America. With approximately 350 Masdevallia species and a number of hybrids, a few species thrive in warmer temperatures, but most flourish in the cool to temperate climate found in the high elevations of the cloud forest. The Masdevallias are suited to the cool coastal regions along the Pacific Northwest and Central to Northern California, but in warmer climates their care is exacting, as they are strongly affected by hot temperatures, watering practices and lack of humidity.
Native to the shady cloud forests, Masdevallias thrive in low-light conditions similar to the Phalaenopsis and Paphiopedilum orchids, preferring 1,000 to 1,500 foot candles. Masdevallias tolerate higher light conditions when the humidity is 70% or more and there is plenty of air circulation, but they cannot tolerate direct sunlight. When growing Masdevallias indoors, a south or east facing window covered with sheer curtains or a fluorescent light provides sufficient light.
The cool to intermediate Masdevallia species thrive when day temperatures range from 50 to 68 degrees F and night temperatures drop to 45 to 56 degrees F. Growers who live in the foggy coastal regions can grow Masdevallias in lath houses or in the deep shade of large trees, such as redwoods. However, because temperature extremes can cause the orchids to lose their leaves, flowers and new growth, the grower should provide alternate methods of cooling the orchids. An evaporative cooler, also known as a swamp cooler, blows cool, moist air around the orchids, helping to reduce heat stress. Fogging or misting systems placed near the orchids also lower the air temperature and raise the humidity.
Masdevallias do not develop pseudobulbs and do not store water. When the potting medium is dry to the touch, place the flowerpot in the sink and add distilled, reverse osmosis or rain water until it drains from the bottom of the pot. Check the potting medium to ensure it is completely moist. Repeat the watering one or two times until the medium is moist throughout. Masdevallias are sensitive to salts; avoid using softened water or hard water from the tap. Water with less than 200 ppm total dissolved salts is best for both watering and misting the orchid. When temperatures are higher than optimum, allow the medium to dry before watering. The roots may rot if they are in constant contact with a wet medium and temperatures are above 80 degrees F.
Fertilize the Masdevallia frequently with a dilute fertilizer solution. At Flowers by the Sea, we plant our Masdevallias in long fiber New Zealand sphagnum moss. We use a 2-4-2 hydrolyzed fish fertilizer, at a rate of one teaspoon per gallon every time we water. Water the orchid thoroughly first, then add the fertilizer solution until it drains from the pot. Alternately, when using bark medium or tree fern fiber, orchid expert Mary E. Gerritsen suggests using a 20-10-10 or 20-20-20 liquid fertilizer at one quarter to one half strength every two to four weeks. Reduce or stop fertilizing during the winter months, when the orchid's growth slows.
If the orchid's leaves turn brown or black at the tips, it is a sign of overfertilizing. Flush the potting medium thoroughly with water and stop fertilizing for one to two months. Never use fertilizer at full strength on a Masdevallia orchid.
Masdevallias require a humidity of 60 to 80% and constant air circulation. When growing the orchid in a lath house or summering it outdoors in the shade, foggers or misters help raise the humidity around the plant. A high humidity helps reduce heat stress when temperatures rise above 80 degrees F. While air conditioning reduces the temperature inside the home, avoid placing the orchid directly in front of the vent; the cold air is extremely dry. Group several plants together on top of a tray filled with pebbles and water and place a cool steam vaporizer nearby to raise the humidity in the room. A ceiling fan or oscillating fan helps circulate air in the room.
Repot the Masdevallia every one to two years in late winter or early spring, before the weather turns hot. Use a fine grade of fir bark, tree fern fiber or New Zealand sphagnum moss as a potting medium. New Zealand sphagnum moss is not the same product as the local garden center's sphagnum moss, they are not interchangeable.
Soak the new planting medium in a bucket of water overnight to ensure that it is completely moist. Also sterilize pruning tools and, if using a recycled clay flowerpot, soak it in a 10% solution for at least 10 minutes. Rinse the flowerpot thoroughly to remove any bleach residue and then place it in a bucket of water to keep it moist until repotting the orchid. A dry clay pot may wick the moisture from the planting medium. It should be the same size or slightly larger than the old flowerpot.
Carefully remove the Masdevallia from the old flowerpot. Gently brush off the old potting medium and examine the roots. Remove any dead or damaged roots, sterilizing the pruners between each cut. If the orchid has developed a dead spot in the center, divide the plant and remove the dead shoots or foliage. Place a mound of moist potting medium in the bottom of the flowerpot. If there is new growth on one side of the orchid, leave extra room for growth on that side, placing the plant off center in the pot. While holding the orchid in place, arrange it over the medium, then fill in around the roots and tamp carefully. Mist the orchid regularly to keep the humidity high, but allow the medium to dry between waterings to allow new roots to form.
Flowers by the Sea provides a selection of the cloud forest species for the Masdevallia enthusiast. In the cool, foggy climate of Elk, California, the orchids thrive in the 55.6 degree F average temperatures. While extremely difficult to grow in hot climates, the delicate beauty of the Masdevallias make the effort worthwhile to dedicated growers.