Growing Pleione orchids (Windowsill Orchids)
The Pleione Orchid is a terrestrial temperate orchid group of around twenty five cool and alpine growing orchids that prefers cool conditions. They originate from areas such as East and Southeast Asia, more specific Taiwan, China and the Himalayas (Nepal) where they thrive on the rocky outcrops and close to the snow line at the edges of woods and forests. These orchids are semi epiphytic and can be found growing on or around the bases of trees and in leaf litter. The Pleione orchid can be cultivated as a houseplant with high maintenance though. Pleione orchids tend do particularly well on window sills on north-facing window sills in the northern hemisphere, and obviously on south-facing window sills in the southern hemisphere where they will be kept cool. A cold frame or a cold greenhouse would be ideal.
The orchid flower color ranges from pink, white, purple, hues of yellow and even deep apricot, peachy colors. The orchid plant itself has green foliage. Closely allied to Coelogyne orchids, the flowers are large, delicately colored and exotic looking. The Pleione orchid flowers during spring and summer and the orchid flowers look good for several weeks.
These orchids are deciduous orchids and prefer a rest during the winter at which time the round squat bulbs should be stored either in their dry compost or removed for storage. The flowers of the Pleione orchid typically develop before the leaves. It is usually at this point that you would need to repot your Pleione orchid bulbs.
The Pleione orchid can tolerate temperatures that range between 6 and 24° Celsius (42 and 78° Fahrenheit). It should also be said that slightly cooler temperatures will not hurt the Pleione orchid, but provided the orchid plant is kept in conditions that are frost free as frost will damage the orchid bulbs. These orchids will definitely stress if they are exposed to temperatures much over 26° Celsius (78° Fahrenheit) during summer.
Pleione orchids like good light during the active growing season and can be left out doors during summer or alternatively can be cultivated close to the glass if grown indoors. During the Pleione orchid winter resting period they can be placed on a shelf in the greenhouse or a cool room with diffused light. In case you are making use of shade cloth in your orchid cultivation methods, you should preferably use the 50 to 60 percent shade cloth.
Water and humidity
The Pleione orchid prefers moist compost during the orchid active growth season. This growth season is usually from early spring through summer right into autumn. It is during this orchid growth spurt that you should ensure to water the orchid plant on a weekly basis (starting sparingly until established) using clean fresh water. From autumn through the winter the compost in which the orchid is planted should be allowed to dry out completely. As mentioned earlier the Pleione orchid is deciduous and will require a rest during the winter.
The Pleione orchid plants are moderate feeders and a balanced orchid plant fertilizer can be applied from spring through to summer at ¼ the pack recommendation given every third watering. During autumn you should change to a higher potash fertilizer (again at ¼ strength) which will encourage the new bulbs to ripen in readiness for the rest period. Refrain from feeding your Pleione orchid by the beginnings of winter and no more should be given until the following spring at which time normal feeding can resume.
Pests and Diseases
Spider mites are small, eight legged, spider-like creatures which thrive in hot, dry conditions (like heated houses). Spider mites feed with piercing mouth parts, which cause plants to appear yellow and stippled. Leaf drop and plant death can occur with heavy infestations. Spider mites can multiply quickly because the female of the species can lay up to two hundred eggs in a life span of a mere thirty days. They also produce a web which can cover infested orchid leaves and orchid flowers. You will need to take prevention and control measures when cultivating Pleione orchids. Keep your Pleione orchid safe by keeping weeds down and removing infested plants.
Dry air seems to worsen the problem, so make sure that you water your Pleione orchid plants regularly. Take advantage of natural enemies such as ladybug larvae. If you decide on making use of a miticide then read and follow all label directions. Concentrate your efforts on the undersides of the leaves as that is where spider mites generally live.
Mealybugs are small, wingless, dull-white, soft-bodied insects that produce a waxy powdery covering. They have piercing/sucking mouth parts that suck the sap out of plant tissue. Mealybugs often look like small pieces of cotton and they tend to congregate where leaves and stems branch. The young tend to move around until they find a suitable feeding spot, then they hang out in colonies and feed. Mealybugs can weaken an orchid plant leading to yellow foliage and leaf drop. They also produce a sweet substance called honeydew (sought after by ants) which can lead to an unattractive black surface fungal growth called sooty mold. This has a more devastating effect on the orchid plants. In the event of your Pleione orchid falling prey to mealybugs, you should isolate the infested orchid plant from those orchid plants that are not infected. Do make use of the mealybugs’ natural enemies, for instance the ladybug, to help when you have a mealybug infestation.
Slugs and snails love moist climates since they are mollusks. Slugs and snails will eat their way through just about anything that is not woody or highly scented. They may eat holes in your orchid plant leaves and strip the entire stem. Keep your garden as clean as possible, and try to eliminate all possible hiding places. Groundcover in shady places and heavy mulches provide protection from the elements and can be favorite hiding places. Beer traps works wonders. Alternatively you can also make use of commercial, chemical controls. Do practice caution when you go this route.
Pleione orchids can also fall prey to aphids. These are small, soft-bodied, slow-moving insects that suck fluids from the orchid plants. They will attack your orchid plant leaving stunted, deformed leaves and buds. They produce a sweet substance called honeydew which can lead to an unattractive black surface growth called sooty mold.
Always try to keep weeds to an absolute minimum, especially around your Pleione orchid plants. There are organic and inorganic products that can be used to control aphids. Ask your local professionals for advice.
Potting mix and Repotting
The Pleione orchid is a terrestrial orchid, though some Pleione orchid species are semi-epiphytic. As such good drainage is important when cultivating this particular orchid. The Pleione orchids will do well in a potting mix that is made up of equal parts loam, sphagnum moss and medium grade orchid compost, this will provide good drainage and moisture retentiveness. Make use of a pot that will accommodate roots and about two years growth, but no more. If your container is too big then you run the risk of over-potting. Make sure that it has a drainage hole. Position the orchid over the pot and ensure that the crown of the orchid plant is just below the rim of the container. Hold the Pleione orchid in that position, then with your other hand, fill pot with moistened soil mix, tapping to firm the orchid potting mix.
Support your Pleione Orchid, especially if it has long flower stalks. Staking is best done as the orchid stem grows and before buds open. Often you will find that orchid growers prefer to insert stake when potting orchid, but it is up to you whether you want to follow this example.
Following are a few commonly cultivated Pleione orchid species. If you are in doubt it is best to grow your orchids in cool conditions and not the alpine conditions.
- The Pleione formosana orchid can be cultivated in both Alpine and Cool conditions. It will flower in spring. The orchid flowers can be soft colors like pale rose and cream. (see above for image)
- The Pleione forrestii orchid prefers Alpine conditions, but will also grow in Cool conditions. This orchid pushes out flowers in spring with a spectacular Primrose Yellow color with red markings.
- The Pleione hookeriana orchid also grows in cool conditions and will also bloom in spring. This particular Pleione orchid bears flowers that are white with purple/yellow blotches.
- The Pleione humilis orchid prefers cool conditions. The Pleione humilis orchid will flower in summer and the orchid flower itself comes in white with rose colored spots.
- The Pleione maculate orchid will thrive being cultivated in cool conditions and will bloom in summer into autumn. The Pleione maculate orchid bears flowers that are white with a blotched Lip.
- The Pleione praecox (lagenaria) orchid is a cool conditions orchid and will bloom during the summer. The orchid flowers of the Pleione praecox is rose and purple colored with a paler colored lip.
General tips when growing Pleione orchids
- Pleione orchids produce numerous small bulbs around the base of the old bulb or around the ‘scar’ formed when the leaves fall, these should be potted up in trays and will be flowering size by the second year.
- The size pot you choose is important too. Select one that is not more than about 1 inch greater in diameter. Remember, many plants prefer being somewhat pot bound.
- Do not fall prey to over-potting.
- Always start with a clean pot!
- A mesh screen, broken clay pot pieces(crock) or a paper coffee filter placed over the hole will keep soil from washing out.
- The potting soil you select should be an appropriate mix for the plants you have chosen.