Paphiopedilum, commonly known as the lady slipper, is a relatively small group of orchids consisting of approximately 77 natural occurring species. These semi-terrestrial plants are native to South China, India, Southeast Asia and the Pacific Islands. Paphiopedilums are excellent plants for the beginner and make great house plants due to their basic environmental needs. Their flowers can last anywhere from 1 to 3 months and when expired should be removed from the plant by cutting the stem off at the point where it emerged from the leaves.
In our Wisconsin climate the Paphiopedilum prefers to be grown in a bright area where they will receive some direct sun. The best exposure is a bright east window where the plant will receive direct sun on the leaves during the morning hours. A south or western exposure is also suitable but be sure the plant receives no more than two hours of direct sun daily.
Some tips for growing in a south exposure: During the winter months the south exposure in our Wisconsin latitude is very bright due to the sun being so low in the horizon. During this period the direct sun in a south window can damage the leaves of a Paphiopedilum, therefore it is recommended to position the plant where it will receive no more than two hours of direct south sun daily. During the summer months the south exposure has the opposite effect where the angle of the sun is very high and no direct light is received. It is then that you will need to move the plant to an east or west exposure to ensure proper light levels or move the plant to a shaded outdoor location or supplement light with an artificial plant light.
Whichever exposure you choose for your Paphiopedilum, try to provide as much light as possible throughout the year without causing sun burn on the leaves. Once your Paphiopedilum is in the flowering stage it is best to shade it from any direct sun to prolong the life of the blooms.
Paphiopedilum can also be grown and flowered successfully under artificial plant lights such as fluorescent lights, high pressure sodium or metal halide. Some artificial plant lights produce enough heat to burn the leaves if positioned too close to the plant. When using any artificial plant light source be sure to position the plants under the lights in accordance to the needs of the plants. If in question, consult Orchids Garden Centre & Nursery for more detailed information.
When it comes to temperature the Paphiopedilum are separated into two major groups. The warm growing types generally have a beautiful mottled or tessellated leaf pattern to them. This type prefers to be grown with a temperature range between 65 degrees minimum at night and 85 degrees maximum during the day.
The intermediate-cool growing types generally have glossy solid green leaves. This type prefers to be grown with a temperature range between 55 degrees minimum at night and 75 degrees maximum during the day. It is known that successful growing of these two types can be achieved by raising them both in the same area whether it is on the warm side or the cool side. Keep in mind that it is generally the cooler night time temperature during the fall or early winter that helps stimulate the plant into flower.
As with any orchid, there are many factors that dictate how often your individual plant will need watering. However, there is one main rule to always follow. Much to the contrary of past cultural information, the Paphiopedilum does prefer to dry out somewhat between watering cycles. In most cases, watering every 7 days is a good interval. Keep in mind that pots of 5 inches or larger tend to stay moist longer and may need an extra day or two between watering, while pots of 3 inches or smaller may need more frequent attention.
To water your Paphiopedilum properly it is best to water the pot thoroughly until water runs freely from the bottom of the pot. Usually this is done at the sink or somewhere you can do a good flushing of the pot. Always remove your pot from any decorative container to allow for proper drainage. Never allow your pot to stand in any water as this will cause root rot. Never use softened water on any of your orchids. Paphiopedilums benefit highly from the use of rain water, bottled water or any other low mineral water source.
The root of a Paphiopedilum is covered with a very fine hair-like feature which is somewhat sensitive to the dissolved salts that are commonly found in most fertilizers. For best results it is recommended to thoroughly water your Paphiopedilum to ensure the potting mix is moist before applying fertilizer.
Paphiopedilum are slight feeders and for that reason we recommend applying a 20-20-20 or similar balanced type fertilizer once every 2 to 3 weeks throughout the entire year. A safe dilution ratio for these plants is one-half teaspoon of fertilizer mixed in one gallon of water. Do not over-fertilize as this will cause permanent root damage.
Like many orchids, the Paphiopedilum enjoys a moderately humid climate of 50% or greater. Therefore while growing these plants indoors it is recommended to increase humidity around the plant. This can be achieved simply by placing your plants on a humidity tray, misting them adequately in the morning, or grouping your plants all together in one area.
We recommend repotting Paphiopedilum every year, to every year and a half. If you are not experienced or comfortable doing this yourself we offer the repotting service at our greenhouse for a small fee. Your recently purchased Paphiopedilum may be ready for a repotting job as soon as it has finished flowering. Inquire with us as to when your individual plant was last repotted. Good indicators for a repot candidate are: when the bark has become broken down, rotted or retains moisture for an extended period; when roots are becoming abundant at the surface; or when the pot is completely root bound.
To properly repot your Paphiopedilum simply remove it from the pot and let the existing potting mix fall away from the roots. Once you have all the mix away from the roots you will be able to distinguish the healthy roots from the not-so-healthy, rotted roots. Trim away any rotted or dead roots. If your Paphiopedilum is completely root bound then no potting mix will fall away, no root trimming will be needed and your potting process will continue from there.
In some cases Paphiopedilums can be divided providing the plant has enough growths to do so. This is a somewhat technical process and is best addressed by a commercial grower or someone who has prior Paphiopedilum dividing experience. If you were to tackle dividing your Paphiopedilum yourself, the rule of thumb is to have at least six mature growths to start with. A safe division is a three to four growth piece. Dividing is done by cutting the rhizome and root zone in a place that will allow you to have the minimum three to four growth piece.
A note about orchid viruses: most commonly the transmission of orchid viruses is caused by using the same cutting tool on multiple plants. The most effective method to reduce virus transmission from plant to plant is to briefly flame sterilize all your cutting tools between use on each plant. A simple Butane torch or a gas stove are handy items for this purpose. This practice should be implemented when repotting as well as when cutting off expired flowering stems.
Once your Paphiopedilum is properly prepared it is time to select the appropriate size pot. Selecting the proper size pot is the next most important aspect in repotting a Paphiopedilum. Select a pot that is only large enough to accommodate the roots comfortably. If you need to force the root mass into the pot, then it is not quite large enough and you may need one size larger. The rule of thumb is not to use any pot larger than what comfortably accommodates the roots. It is always recommended to use a new pot and be sure it has adequate drain holes in the bottom and/or side.
Next, set your plant into the pot and begin adding our moistened fir bark orchid potting mix. Work the mix in between the roots by gently shaking or tamping the pot to allow the mix to fill in between the root crevasses. Position the plant so the junction of the roots to the plant is just below the surface of the mix.
Once the pot is nearly full of the mix, begin to pack the mix somewhat firmly to properly anchor the plant into the pot. Sometimes a blunt tool is needed to properly firm up the mix. Repotting is now completed. Wait one week and then water the plant thoroughly.
For more assistance with your Paphiopedilum or any other Orchid, please call us at 608-831-4700, send an email, or visit our store.
Happy growing, from Orchids Garden Centre & Nursery!