The Zygopetalum genus is an orchid native to the tropical rainforests of South America. This is an epyphitic orchid considered to be a tough plant with tender parts sensitive to less-than-ideal growing conditions.
Zygopetalums are highly fragrant with perfumes ranging from chocolaty to spicy and peppery. Other scents are described as similar to hyacinths or freesias. With proper care, these sturdy orchids will bloom up to four times a year for a period lasting three to four weeks. Flowers are 2 to 4 inches in size and appear in shades of purple, burgundy, green and white with spotted and patterned petals and lips. Some hybrids will produce flowers with shades of blue; a color considered rare for orchids.
|Plant Type||Perennial, epiphyte|
|Mature Size||12-24 in. tall|
|Bloom Time||Up to 4 times annually|
|Flower Color||Purple, burgundy, green, white, blue|
|Hardiness Zones||9-10, USDA|
|Native Area||Tropical South America|
Zygopetalum Orchid Care
Zygopetalum orchids are true epiphytes with slender light green leaves and flower spikes that arise from pseudobulbs. These are thickened areas of the stem somewhat similar to the rhizomes of irises. Unlike the hard, knobby iris rhizome, stems and pseudobulbs on the Zygopetalum orchid are delicate and require gentle handling to avoid breakage.
Most common types of Zygopetalum can be grown in shallow pots, however the rarer, more rhizotomaceous types thrive only on tree fern slab culture or in baskets. Maintenance for species that grow naturally at higher elevations will differ from those that appear in coastal and lowland rainforests.
What Is an Epiphyte?
An epiphyte is a plant that grows on another plant but is not parasitic, such as the numerous ferns, bromeliads, air plants, and orchids growing on tree trunks in tropical rainforests.
Zygopetalums need bright, filtered light to bloom. Providing some type of partial shade will help to avoid sunburn and brown spotting on the tender leaves and pseudobulbs. Use a shade cloth or place the plant near a window that receives bright light without direct exposure to the sun.
Like all orchids, Zygopetalums do not tolerate wet, soggy soils. Epiphytic orchids absorb moisture and nutrients through air roots, so a consistently wet growing medium will cause root rot and fungal infections.
These orchids like a slightly acidic soil and do well in baskets or shallow pots using fine orchid bark with 20 percent perlite. Coarse peat, sand and redwood bark shavings can improve moisture retention and still allow adequate drainage after watering.
Frequent blooming of these orchids can be encouraged with more frequent watering, as often as every two days throughout the growing season. When the blooms have dropped, watering can be reduced to once a week. This is an orchid that does not go into full dormancy after bloom so its growing season will be dependent on the conditions you provide. In temperate climates, water should be reduced during winter months to provide a rest period. This plant is also sensitive to salts and minerals in tap water, so it's best to use filtered or distilled water at room temperature.
Temperature and Humidity
The optimal temperature for this orchid is 70 to 75 degrees during the day and 10 degrees lower at night. Types that grow naturally in mountain rainforests will perform best with nighttime temperatures even a bit lower, around 50 to 55 degrees. Zygopetalums can survive at 50 degrees in the winter if water is withheld and the plant is kept dry.
This orchid will also benefit from regular misting when not in bloom. Best humidity levels range between 60 and 70 percent with up to 80 percent humidity in summer. Mist your orchids in the morning to help the leaves dry before nightfall. Wet foliage can lead to stem decline and flower loss. Avoid misting when in bloom to discourage botrytis petal blight.
Good air circulation is also important for orchid health. A slightly opened window or fan can keep the air moving around your plant—air should not be blowing directly on the plant.
Zygopetalum orchids are not fussy about fertilizer, so slow release and liquid feed are both suitable. Adding dolomite as a top dressing in late spring will help to strengthen the plant's tender leaves. For the best chance of repeat blooming periods, fertilize every two weeks during the growing season with a 30-10-10 formula, or you can feed year round with 20-20-20 at half strength. Avoid fertilizers with high nitrogen content as this can cause the foliage to stretch and become brittle.
Types of Zygopetalum Orchids
The World Monocot checklist recognizes 15 types of Zygopetalum orchids, though dozens of hybrid types have also been identified.
- Zygopetalum maculatum: 1 or more 16-inch flower spikes per pseudobulb, and each bears 8 to 12 flowers. Petals are green with red spots and bars. The orchid lip is one large lobe with purple and white veins.
- Zygopetalum maxillare: Bloom fragrance hints of chocolate. Petals are green and burgundy with a purple and lavender ridged lip.
- Zygopetalum triste: 9-inch stems produce 3 to 5 blooms with petals in a rich burgundy hue. Fragrance is described as peppery and spicy.
- Zygopetalum intermedium: Yellow-green petals display purple blotches with a blue spotted white lip. The orchid sends up flower spikes of 8 to 12 inches.
- Zygopetalum crinitum: Large flowers up to 4 inches across with distinct yellow-green leaves, and burgundy spotted petals with a purple striped white lip. Blooms on flower spikes 8 to 12 inches tall.
The easiest way to propagate Zygopetalum is to divide your existing plant by removing offsets (pups) from the mother plant. This is usually done in late spring to early summer with pseudobulbs that are at least 1/3 the size of the main bulb. As a general rule, each division should include 3 pseudobulbs with active roots. Always leave the mother plant with three active bulbs. Stems and bulbs of these orchids are easily damaged, so be ready to take your time and handle the process gently and with extra care. Gather together a sharp scissors or snips, growing medium, 4- to 6-inch shallow pots, and gloves (optional) and follow these directions.
- Twenty-four hours before the division, place the orchid in its pot in a sink or bucket filled with cool, not cold water. Let the potted plant soak for 30 minutes, then drain excess water.
- Remove the orchid from the pot and use one hand to gently grasp the plant close to the node of a pseudobulb making sure to leave at least three pseudobulbs with the mother plant. Remove any growing material that's in the way.
- Gently push the offset down while supporting the mother plant with your other hand. You should hear a snap.
- Carefully separate the roots of the two plants working slowly in order to keep the roots intact and as undamaged as possible.
- Using a sharp sterile scissors or snips remove any roots that appear brown or shriveled. Cut back damaged roots to plump healthy growth.
- Place the new plantlet in a shallow pot and fill in around the roots and bulbs with a mix of fine orchid bark and perlite. Make sure your pot is large enough to leave 1 inch of room all the way around between the plant and the pot rim. Zygopetalum orchids do not like to be potbound.
- Place the new plant in a spot where it will receive the right temperature, humidity and sun exposure and mist or water lightly.
- When new leaf buds appear on the pseudobulbs, your orchid is producing new roots. You can begin routine maintenance.
Potting and Repotting Zygopetalum Orchids
Zygopetalum orchids, unlike many other orchid genuses, do not like to be potbound, so choose a wide, shallow pot with large drainage holes.
Repotting should take place every 3 to 4 years when new leaves are stretching upward. Use a pot the next size up with adequate drainage. The roots are soft so some breakage may occur. Hydrating the plant in a sink or bucket of cool water for 30 minutes 24 hours before repotting can help prevent transplant shock resulting from any root damage.
Common Pests and Plant Diseases
Zygopetalum orchids are vulnerable to several fungal diseases that usually appear as discoloration on the leaves. Common problems include botrytis, anthracnose, and cercospora. Look for orange, brown or black spots or lesions that become larger or spread. Most fungal infections are the result of too much water or moisture, poor air circulation, or consistently high temperatures.
Remove the affected plant parts a sharp sterile knife or snips and irrigate the plant multiple times over the course of several weeks, allowing the soil to dry slightly between drenchings. Alternatively, you can try washing the leaves using a soft cloth dampened with warm water. You can also apply a fungicide although they are not effective against every fungal infection. After treating the orchid, isolate it from other plants in a cool shaded location until it recovers.
Common pests include spider mites, aphids, mealybugs, scale and thrips. Look for leaves that appear chewed, discolored, or have deposits of a white powdery or sticky substance. Scale insects can be removed with the scrape of a fingernail. Most other insects can be eliminated by gently washing the leaves and drenching the growing medium. In cases of severe infestation, you may need to repot the orchid with fresh material or apply a treatment of neem oil.
How to Get Zygopetalum Orchids to Bloom
During the growing season, usually spring through fall depending on your climate, feed your Zygopetalum orchid every two weeks with a 30-10-10 orchid fertilizer. Make sure the plant receives plenty of bright indirect light during the day with even temperatures and good air circulation. Nighttime temperatures should also be consistent but 5 to 10 degrees lower than during the day. Place the orchid on a tray of moistened pebbles to raise humidity levels and water when the top one-third of the growing medium becomes dry.
Common Problems with Zygopetalum Orchids
Most common problems associated with this orchid can be traced to incorrect watering, light, or temperature.
Stem and Pseudobulb Rot
These conditions are the result of overwatering. Remove the orchid from its pot and, using a sharp sterile knife or snips, remove any plant parts that have turned brown or mushy. Replace the orchid in a pot with fresh material, place it in spot with bright, indirect light and withhold water for one week.
Yellow or Dark Green Leaves
The leaves of Zygopetalum should be long, slender, and light green with a yellowish caste. If the leaves become completely yellow, this is likely the result of too much direct sunlight. Dark green leaves indicate the orchid isn't receiving enough light. Move the orchid to a new location where it will receive the correct amount of light. It is a natural process for older, lower orchid leaves to turn yellow and drop.
If your orchid fails to bloom at least once, annually, this is likely caused by the wrong kind of light or uneven temperatures. Make the necessary adjustments to provide plenty of bright, indirect light. Add a shade cloth or move the plant to a more ideal location. Consider placing a thermometer near the orchid to better monitor fluctuations in temperature.
How long will my Zygopetalum orchid live?
Due to the delicate nature of the Zygopetalum structure, these orchids can survive about 7-10 years with good maintenance and gentle handling.
What are some popular Zygopetalum orchids?
The following three types are specifically recognized by the American Orchid Society. Zygopetalum maculatum (syn. mackayi) 'Maui Jazz', Z. maxillare ' YoshioImogawa', Z. triste 'Seagrove's Blue Caribou'.
Can I grow a Zygopetalum orchid in a basket?
Yes. Growing epiphytic orchids in baskets is similar in many ways to growing them in shallow pots. The biggest differences include using more mosses and other materials that hold water as part of the growing medium. Also, methods for providing moisture for your plant may require a greater amount of misting.