General information
Orchids of the Paphiopedilum genus are among the easiest to care for and produce beautiful, long-lasting blooms. Let's learn more about these fascinating plants. The Paphiopedilum genus includes approximately 80 species and hundreds of hybrids. Some have striped or variegated leaves, others feature flowers with spots, stripes, or patterns. Many of these varieties are highly prized by collectors.
Paphiopedilums are often called “slipper orchids” or “Venus slipper orchids” because of their distinctive sac.
However, they are different from the wildflowers 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 a hanging holder as is sometimes used for epiphytic, tree-dwelling orchids.
Growing Paphiopedilum terrestrial orchids outdoors is possible even in tropical and subtropical climates.
These Southeast Asian plants have dense flowers that last from one to three months. There are varieties with multiple, sequential, and single flowers, in various sizes, shapes, and colors.
Light requirements
Paphiopedilums belong to the group of orchids that require little light. Place them in a bright window, but protect them from midday sun. The leaves should be a medium green. If they are too pale or yellowish, the plant may be getting too much light.
An east-facing window is ideal; west- or south-facing windows can also be used, provided they are shaded with a sheer curtain. You can tell if the plant is getting too much light by looking at the leaves. A reddish tinge at the edges indicates that the plant needs more shade. If the paph doesn't bloom again, it may not be getting enough light.
Temperature requirements
Paphiopedilums are divided into two temperature groups: warm and cool. The attractive variegated-leaf varieties come from temperate zones, while the uniformly green-leafed varieties come from higher, cooler altitudes.
Simple Leaf – Fresh Growth
Variegated Leaf – Intermediate to Warm Growth
In general, species with mottled foliage and species or hybrids with striped leaves and multiple flowers thrive in intermediate to warm climates, preferring daytime temperatures of 70-80°F (21-26°C) and nighttime temperatures of 55-65°F (13-18°C). Complex hybrids grow in colder areas and flower primarily during the winter season. These varieties prefer nighttime temperatures of 55-63°F (13-17°C) with daytime temperatures around 65-70°F (18-21°C). All tolerate summer heat as long as they are watered regularly, shaded, and kept humid. Varieties with mottled foliage thrive best in a warmer house or apartment and can often flower twice a year.
Keep in mind that temperatures near the window, on the windowsill, will be cooler or warmer than the average indoor temperature. Paphios can be grown outdoors in mild climates. Protect the plants during low temperatures by avoiding moisture on the leaves or crowns and, in summer, by avoiding sunburn.
Water requirements
Watering frequency will depend on whether the plant is potted with bark or sphagnum moss, as well as the amount of light and heat. Paphiopedilums require more frequent watering than other orchids because they don't have pseudobulbs to store water. Bark retains less water, so more frequent watering is usually sufficient: every two days is usually sufficient. If the plant is potted with moss, water when the top is dry. Be careful not to overwater to avoid root rot. You'll soon be able to tell by the weight of the pot if it's time to water again. If in doubt, wait a day.
Paphiopedilums should be kept consistently moist, but not soaked. Check the soil frequently to determine if watering is needed. Normal watering intervals are seven to ten days. Like all orchids, it's important to water in the morning. This ensures complete evaporation of water on the foliage and crown by sunset, thus preventing bacterial and fungal rot. Water the plant when drought approaches. Use rainwater, distilled water, reverse osmosis water, or tap water. Do not use softened water. Place the plant in the sink when watering and allow it to drain well. In most growing conditions, watering is done every three to seven days, depending on the size of the pot.
“PLANTS SHOULD NEVER BE IN WATER!”
Humidity requirements
Paphs prefer a humidity level between 45% and 70%. This can be achieved by using humidifiers or by filling a saucer with gravel and placing it under the plants. The water under the stone will slowly evaporate, slightly increasing the humidity level. Make sure the pot isn't submerged in water, as this will cause the roots to rot. Homemade humid saucers are another option you can use to arrange your plants.
Give your plants enough space for air circulation. Overcrowding can cause problems with insect and fungal infestations. A small fan will help ensure good air circulation around your plants.
Flowering
They bloom mainly in spring, early summer, or early fall, but under the right conditions they can bloom year-round. The flowers range from small to large and are highly specialized to attract specific pollinating insects, 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's important to rinse with clean water every month to remove excess fertilizer, which can burn the roots. In cold weather, fertilizing once a month is sufficient.
Recommended fertilizers:
- Balanced fertilizer for growth: 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 (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. Potting mixes vary greatly; most consist of fine or medium-quality fir bark, with various additives such as perlite (sponge rock), coarse sand, and sphagnum moss. Good water retention and excellent drainage are essential. Large plants can be divided by pulling or cutting the leaf fans into groups of three to 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 the pot with substrate, so that the root-stem junction is buried 1–2 inches (2.5–5 cm) deep in the center of the pot.
Once flowering is complete, cut the stem back to the height of the leaves. Continue watering and fertilizing, and within a year, a new stem will grow and the flowering cycle will begin again! Once the plant has finished flowering, it's time to repot your orchid.
Pests and other problems related to Paphiopedilum
Fungal and bacterial diseases of Paphiopedilum are common due to the high humidity levels they require to survive. Fungal diseases cause problems such as root rot, leaf spots, leaf discoloration, and flower deformity.
