Currently the Miltonia orchid (Miltonia spp.) genus includes only species native to Brazil. They have somewhat more star-shaped flowers and prefer slightly warmer conditions than do the former miltonias, which were widely known as pansy orchids (Miltoniopsis spp.) and now belong to the Miltoniopsis genus. Both types are hardy only in U.S. Department of Agriculture plant hardiness zones 10 through 11. Due to their need for high humidity, miltonias are most suited to a greenhouse, but can thrive in the home too if provided with a little extra care.
Medium and Moisture
Your miltonia orchid should be growing in a fast-draining medium that still retains some moisture. Examples include the American Orchid Society’s recommended mix of 2 parts tree fern fiber and 1 part chopped sphagnum moss, or "Orchids for Dummies" suggestion of 4 parts fine-grade fir bark, 1 part fine charcoal and 1 part horticultural grade perlite. The orchid's container must have drainage holes.
Water the plant frequently enough that its medium never entirely dries out. That usually will mean about twice a week during summer and only once a week during winter. Place the orchid atop a humidity tray or near a frequently used sink where the air stays moist. If its leaves look pleated, it isn’t receiving enough water and/or humidity.
Warmth and Windows
A miltonia orchid can tolerate any temperatures between 60 and 90 degrees Fahrenheit. Ideally, however, it should be kept at conditions between 75 and 80 degrees F during the day, falling to between 60 and 65 degrees F at night.
The plant enjoys bright light, but not much direct sun, so place it under a grow light or on an east-facing windowsill where it receives sunlight only in the morning. If you must position it on a south- or west-facing windowsill, hang a sheer curtain between it and the windowpanes. Should its light green leaves turn yellow, they probably are receiving too much light.
Sustenance and Salts
Feed a miltonia growing in fir bark with a half-strength 30-10-10 plant food once every two weeks, mixing 1/4 teaspoon of the crystals into 1 gallon of water. If it is planted in another medium, use a 20-20-20 fertilizer instead, at the rate of 1/2 teaspoon per gallon of water.
During the spring months, switch to a bloom-booster plant food such as 10-30-20, also applied once every two weeks at the rate of 1/2 teaspoon of crystals per gallon of water. A miltonia will usually flower at some point between May and July. After the blooms fade, clean your pruning shears with rubbing alcohol and snip the flower stems off about 1 to 2 inches above the base of the plant. Resume using the 30-10-10 or 20-20-20 plant food at half strength through autumn, but drop that amount to one-quarter strength during winter.
This orchid won’t tolerate a buildup of fertilizer salts in its medium, so leach its pot about once a month to remove those. Water the plant as usual first. About one hour later, set its pot in an unstopped sink and pour water equal to twice the volume of the pot through its medium. For instance, a 5-inch-wide and 5-inch-tall pot usually contains about 1 quart of orchid bark, so you would pour 2 quarts of water through that bark. Leave the pot in the sink until water has stopped dripping from its drainage holes.
Scale and Spider Mites
Spider mites and scale insects are the pests most commonly found on miltonias. Spider mites cause a stippling pattern on the foliage sometimes accompanied by webbing, and scale insects resemble waxy brown bumps. Treat both with pure neem oil, by adding 2 tablespoons of the oil and 1 1/2 teaspoons of dish detergent to 1 gallon of water. For mites, spray the plant thoroughly once a week for two weeks. For scale, spray it once every two weeks for two months. Wear goggles and a respirator during the spraying process to protect your eyes and lungs.
- American Orchid Society: Miltonia Including Miltoniopsis
- Beautiful Orchids: Miltonia
- Swansons Nursery: Miltonia & Miltoniopsis Orchid Care
- Bloom-Again Orchids: 50 Easy-Care Orchids That Flower Again and Again and Again; Judy White
- The House Plant Expert: Book 2; D. G. Hessayon
- Orchid Growing for Wimps; Ellen Zachos
- Orchid Species Culture; Miltonia Culture
- Orchids for Dummies; Steven A. Frowine
- Logee’s Greenhouses Spectacular Container Plants; Byron E. Martin and Laurelynn G. Martin
- The Plant Book; Susan Page and Margaret Olds, Editors
- Photo Credit Jupiterimages/Stockbyte/Getty Images
- The Orchid Specialist; David Squire