These Southeast Asian plants have flowers of heavy substance, lasting from one to three months. There are multi-flowered, sequential flowered and single flowered varieties of many different sizes, shapes and colors. To this day there is no accurate way to clone Paphiopedilums, making mass production difficult. For this reason, Paphiopedilum are one of the most unique and popularly collected orchids in the world, with many varieties being easy to grow indoors.
Light and Shade
Paphiopedilum do well in shaded light (1000 to 1500 foot-candles), so that if a hand is passed over the leaves it does not produce a shadow. We recommend growing in east or west-facing windows, although the east exposure is better because the temperature is lower in the early part of the day when the plant is receiving the greatest amount of light. South-facing windows should only be used if shielded from the sun using a sheer curtain. If using artificial light to grow indoors, LEDs are the best option for orchids. Paphiopedilum prefer 11 hours of artificial light in winter, and 14 to 16 hours in summer. The artificial light market has expanded greatly in recent years, so a quick Google search will result in a variety of lighting options and price ranges.
Temperature and Humidity
There are both warm and cool growing Paphiopedilum. Generally speaking, those with mottled foliage and the strap-leafed, multi-flowered species do best in intermediate to warm conditions, preferring daytime temperatures of 70°F to 80°F (21°C to 27°C), and nighttime temperatures of 55°F to 65°F (13°C to 18°C). The mottled leafed varieties do best in a warmer house or apartment and can often bloom twice a year.
A majority of the cool-growing species are native to India, where they grow at higher elevations. Paph. Complex hybrids are cool growing and bloom mostly during the winter season. These types prefer daytime temperatures of 65°F to 75°F (18°C to 24°C), and nighttime temperatures of 55°F to 62°F (13°C to 17°C). They will all tolerate the heat of summer as long as they are regularly watered, shaded and kept in humid conditions.
Paphiopedilum thrive under high humidity and will benefit from humidity levels between 40% and 70%. This can be achieved at home with the use of a humidifier or a Humidity Tray and Grid. Just make sure that the plant is not standing in water or the roots will rot.
As semi-terrestrial orchids, Paphiopedilum like to be kept fairly moist, with the media becoming only slightly damp between waterings. During warm dry weather, they may need to be watered 2 times a week. These orchids form wilted leaves, yellowed leaf tips, and rapid yellowing throughout the oldest base leaves, when not receiving enough water. If this happens, check the root system. Over-watering may have caused the roots to rot, thereby depriving the plant from absorbing water. If the roots are healthy, you are likely under-watering and should increase your watering schedule accordingly.
We always recommend watering in the morning, as this gives the leaves time to dry and avoid bacterial growth overnight. If possible, use water low in alkalinity, such as rainwater, distilled water, or reverse osmosis water. If you have a dehumidifier in your home, the water that collects in the tray is excellent for watering orchids.
We highly recommend Green Jungle Orchid Food, specially formulated to provide orchids with the nutrients they would naturally encounter in their wild habitats. This is the fertilizer that we developed to use on our own plants in production, with excellent results for decades! This formula works best with water low in alkalinity (such as rainwater, distilled water, or reverse osmosis water). However, you may use tap water, keeping in mind that mineral buildup will require repotting more frequently, on the order of every 1 to 2 years.
If potting in bark mix, fertilize every time you water, flushing with non-softened water once a month. This rinses the media of salt and mineral buildup. When potting in sphagnum moss or rockwool mix, fertilize every 3rd watering year round.
Paphiopedilum do well in a light, porous medium, capable of holding moisture while draining thoroughly upon watering. At Orchids Limited, we recommend potting these plants in New Zealand Sphagnum Moss, our Modern Moisture Retentive Mix (contains rockwool), as well as the Small or the Medium grade of our Traditional Orchid Bark Mix. Use the Classic grade for plants in pots smaller than 3.25", and the Power grade for plants in pots 3.25" and larger.
Repot once per each year to year and a half, preferably in the spring or fall when temperatures are mild. Remove all dead or dying roots from the plant, carefully taking off the old compost without causing damage to the live roots. Pot with oldest growth closest to the rim of the pot, allowing room for 1 to 2 years growth. We find that plastic pots work best for Paphiopedilum. If the mix is old, crumbly and sour, carefully remove the media and rinse the root system. Trim off any dead roots and dead growths. Position the plant with its oldest growths to the edge of the new pot. Then, spreading the plant roots out, fill in the space with the potting medium. Should you wish to divide your plant at this time, each section should have 2 or three growths in addition to any new leads. Old leafless growths should be removed if the procedure will cause no damage to the rest of the plant. You can watch our video on dividing orchids here.
To avoid the transfer of orchid diseases, it is standard procedure to sterilize all cutting and potting instruments before using them on a plant. This can be done by flaming pruning shears with a butane torch, or by spraying with rubbing alcohol and wiping with a clean paper towel.
The main pest that Paphiopedilum attract are mealybugs, which will hide in the leaf axis. The best treatment for mealybug is either a homemade pesticide of 1:1 parts water & rubbing alcohol, with a few drops of dish soap added. Spray the plants every few days, washing off the dead bugs in between. For large outbreaks, an application of a specially formulated pesticide spray every few days is more effective.