General Information
Paphiopedilum orchids are among the easiest to care for and produce beautiful, long-lasting blooms. Let’s find out more about these fascinating plants. The genus Paphiopedilum comprises about 80 species and hundreds of hybrids. Some have striped or variegated leaves, while others have flowers with spots, stripes, or patterns. Many of these varieties are highly prized by collectors.
Paphiopedilums are often called “slipper orchids” or “lady’s slipper” due to their distinctive pouch.
However, they are different from the wild flowers known as lady's slipper orchids.
Most Paphiopedilum species are terrestrial orchids, meaning they grow in soil.
Terrestrial orchids should be grown in pots, not in hanging baskets as is sometimes used for epiphytic orchids that live on trees.
Growing terrestrial Paphiopedilum orchids outdoors is also possible in tropical and subtropical climates.
These plants from Southeast Asia have thick-textured flowers that last one to three months. There are multifloral, sequential-flowering, and single-flowering varieties, in various sizes, shapes, and colors.
Light Requirements
Paphiopedilums belong to the group of orchids that require low light. Place them in a bright window, but protect them from midday sun. Leaves should be a medium green. If they are too light or yellowish, the plant may be receiving too much light.
An east-facing window is ideal; west or south-facing windows can also be used if shaded with a sheer curtain. You can tell if the plant is getting too much light by observing the leaves. A reddish hue on the edges indicates that the plant needs more shade. If the paph is not reblooming, it may not be receiving enough light.
Temperature Requirements
Paphiopedilums are divided into two temperature groups: warm-growing and cool-growing. The attractive variegated leaf varieties come from temperate zones, while uniform green-leaf varieties come from higher, cooler altitudes.
Plain leaf – Cool growth
Variegated leaf – Intermediate to warm growth
In general, variegated foliage species and species or hybrids with striped leaves and multiple flowers thrive in intermediate to warm climates, preferring daytime temperatures of 21-26 °C and nighttime temperatures of 13-18 °C. Complex hybrids grow in cool zones and flower mainly during the winter season. These varieties prefer nighttime temperatures of 13-17 °C with daytime temperatures around 18-21 °C. All tolerate summer heat provided they are watered regularly, shaded, and kept in humid conditions. Variegated leaf varieties thrive best in a warmer home or apartment and can often flower twice a year.
Keep in mind that temperatures near the window, on the windowsill, will be colder or warmer than the average house temperature. Paphs can be grown outdoors in mild climates. Protect plants during low temperatures by avoiding moisture on the leaves or in the crowns, and in summer, by preventing sunburn.
Water Requirements
Watering frequency will depend on whether the plant is potted in bark or sphagnum moss, as well as the amount of light and heat. Paphiopedilums require more frequent watering than other orchids because they do not have pseudobulbs to store water. Bark retains less water, so it will require more frequent watering: every other day is usually sufficient. If the plant is potted in moss, water when the top is dry. Be careful not to overwater to avoid root rot. You will soon be able to tell by the weight of the pot if it's time to water again. When in doubt, wait a day.
Paphiopedilum should be kept consistently moist, but not waterlogged. Check the medium frequently to determine the need for water. Normal watering intervals are between seven and ten days. Like all orchids, it is important to water in the morning. This ensures complete evaporation of water on the foliage and crown by dusk, thus preventing the formation of bacterial and fungal rot. Water the plant when it is approaching dryness. Use rainwater, distilled water, reverse osmosis water, or tap water. Do not use softened water. Place the plant in the sink when watering and let it drain well. Under most growing conditions, watering is done at intervals of 3-7 days depending on the pot size.
“PLANTS SHOULD NEVER STAND IN WATER!”
Humidity Requirements
Paphs prefer humidity between 45% and 70%. This can be achieved by using humidifiers or by filling a saucer with gravel and placing it under the plants. Water under the gravel will slowly evaporate, slightly increasing the humidity level. Make sure the pot does not sit in water, as this will cause root rot. DIY moist saucers are another option you can use to set up your plants.
Allow your plants enough space for air circulation. Crowding plants can lead to insect infestations and fungal problems. A small fan will help ensure good air circulation around the plants.
Flowering
They flower primarily in spring, early summer, or early autumn, but under the right conditions, they can flower all year round. The flowers are small and large and are highly specialized to attract specific insect pollinators, and many have a strong, pungent odor that primarily attracts flies.
Fertilizer Requirements
Fertilize regularly, but be careful to avoid burning the fleshy, hairy roots. High-nitrogen fertilizers are recommended for plants grown in pots in any bark mix. It is important to flush with clean water monthly to remove excess fertilizer, which can burn the roots. In cold weather, fertilizing once a month is sufficient.
Recommended Fertilizers:
- Balanced growth fertilizer: 20-20-20 (NPK) – 1 gram per liter of water – Spray once every two weeks (14 days) (only in warm seasons)
- High nitrogen fertilizer for flowering: 30-10-10 (NPK) – 0.5 grams per liter of water – Spray weekly (all year round)
Repotting, Substrates and Propagation
Repotting should be done approximately every two years, or as the substrate decomposes. Seedlings and smaller plants are often repotted annually. Mixes vary enormously; most are composed of fine or medium quality fir bark, with various additives such as perlite (spongy rock), coarse sand, and sphagnum moss. Good water retention and excellent drainage are necessary. Large plants can be divided by pulling or cutting the leaf fans into groups of three or five shoots. Smaller divisions will grow but may not flower. Spread the roots over a small amount of substrate at the bottom of the pot and fill it with the substrate so that the junction between roots and stem is buried 2.5-5 cm deep in the center of the pot.
Once flowering has finished, cut the stem down to leaf level. Continue to water and fertilize, and within a year, a new stem will develop, and the flowering cycle will begin again! When the plant has finished flowering, it will be the right time to repot your orchid.
Pests and Other Paphiopedilum Related Problems
Fungal and bacterial diseases in Paphiopedilums are common due to the humidity levels they require to survive. Fungal agents cause problems such as root rot, leaf spots, leaf dieback, and flower deformation.
