Slipper orchid

Slipper orchid: how do you recognise it?

Growth habit

Compact, evergreen orchid, about 35 cm tall and 30 cm wide, without pseudobulbs. New growths form next to the old ones.

Leaves

Strap-shaped, leathery and glossy green, 20–30 cm long, arranged in a fan.

Flower

One flower of about 8–10 cm per stalk: a white top sepal with brown spots, yellow-green petals with brown veins and a rounded, brownish-yellow pouch.

Roots

Thick, fleshy and shallow. They need air and must never dry out completely or sit in heavy, wet soil.

Flowering time

From October to January. The flower often stays attractive for several weeks to several months.

Flowering: October–January · Plants: March–April

Why grow it?

• Flowers from October into January, in the dark months when almost no other houseplant is in bloom.
• A single flower often stays attractive for weeks or even months: long-lasting beauty for little effort.
• Compact, about 35 cm tall, so it fits easily on a windowsill.
• Evergreen, fresh green fan of leaves that looks good even without a flower.
• Does not need a warm room: cool nights actually help it to flower.

Slipper orchid: where does it grow best?

• Bright light without direct sun: an east-, west- or north-facing window, or a spot just behind a south-facing window. Direct midday sun scorches the leaves.
• An airy, moisture-retentive orchid mix of fine bark with some perlite and perhaps a little peat or sphagnum moss, slightly acid.
• 18–25 °C by day. In autumn, cooler nights of 10–13 °C help to set flower buds. Never below 10 °C.
• A humidity of about 50–70 % is ideal: stand the pot on a tray of damp clay pebbles, without the pot sitting in the water.

Light

Bright, out of direct sun

Potting soil

Airy, humus-rich compost

Acidity

Acid

Watering

Moderately

Size

0.35 m tall, 0.3 m wide

Temperature

Minimum 10 °C

Goes well with

• Moth orchid (Phalaenopsis): The same bright spot without sun and the same orchid mix.
• Ferns: Enjoy the same humid air and filtered light.
• Calathea: Tolerates the light shade and humid air that a slipper orchid likes.
• Peperomia: A compact foliage plant for the same windowsill.

Slipper orchid: when and how to plant it?

Plant in March–April.

1. Repot in March–April, just after flowering, roughly every 1–2 years: bark breaks down and then becomes sour and compacted.
2. Choose a pot with drainage holes, at most one size larger: a slipper orchid flowers best in a slightly snug pot.
3. Take the plant out of the pot and cut away old bark and rotten or empty roots with clean scissors.
4. Set the plant so that the base of the fan stays just above the mix. Fill in with fine bark mix and firm gently.
5. Water only lightly in the first week and regularly after that; never let the mix dry out completely.

Care

Water

Keep the mix evenly slightly moist: never soggy and never completely dry, because the plant has no pseudobulbs as a reserve. Water as soon as the surface feels just dry, usually 1–2 times a week, preferably with rainwater or low-lime water. Pour along the edge of the pot.

Feeding

From March to October every 2–4 weeks, a quarter to half dose of orchid feed. Flush the mix through every now and then to prevent salt build-up. In winter little or none.

Light

A bright spot without sun is the key to flowering: too dark gives plenty of leaves and few flowers.

Humidity

Aim for 50–70 %: a tray of damp clay pebbles and a little air movement help. Do not mist the flowers.

Flower stalk

Cut the stalk off at the base after flowering once it has dried up; the next flower comes from the new growth.

Tip: Never water into the heart of the leaf fan and never let the mix dry out completely: it has no pseudobulbs as a water reserve. Keep it bright without sun; cool autumn nights (10–13 °C) encourage flowering.

Slipper orchid: when to prune it?

When: Real pruning is not needed. After flowering, usually in February–March, cut off the withered flower stalk.

How:

• Cut the flower stalk off at the base with clean scissors once it is brown and dry.
• Remove completely yellow or brown leaves at the base; leave green leaves in place.
• Disinfect the scissors with alcohol between plants so that you do not pass on diseases.

Caution: Do not cut off healthy green leaves: the plant needs them to store energy for the next flowering.

Pruning calendar and basic rules

Propagation

Division

In March–April after flowering, when repotting. A plant with at least six growths can be cut into two parts of at least three growths each with a clean knife. Pot each part in fresh mix and keep it slightly moist.

Seed

Orchid seed germinates only in sterile culture in a laboratory, so it is not a method for home growers.

Slipper orchid: how does it get through the winter?

• Not hardy: the minimum temperature is 10 °C. It can never overwinter outdoors.
• It flowers in winter: keep it bright and cool (15–20 °C by day). Cooler nights of 10–13 °C in autumn encourage bud formation.
• Keep it away from radiators and cold windows: draughts and dry heated air make buds drop.
• Water slightly less in winter, but never let the mix dry out completely.

Diseases and pests

• No flowers: Usually too dark or autumn nights that are too warm. Move the plant somewhere brighter (without sun) and give it cooler nights of 10–13 °C in October–November.
• Brown leaf tips: Caused by dry air, hard water or salt build-up. Use rainwater, flush the mix through and raise the humidity.
• Crown rot: Water standing in the leaf fan causes soft, black rot. Water along the edge of the pot, dry the centre and cut away affected tissue.
• Mealybugs and scale: White fluffy patches or brown shields between the leaves. Wipe them off with a cotton bud dipped in a little alcohol or soapy water and repeat weekly.

Through the year

• January: Last flowers. Keep bright and cool, water moderately, do not feed.
• February: Cut off the withered flower stalk. Do not feed yet.
• March: Repot and divide if needed after flowering. Start feeding again.
• April: Repotting or dividing still possible. A weak feed every 2–4 weeks.
• May: Growing season: water regularly, light without direct sun.
• June: Growth. Water regularly, shade from strong sun.
• July: Growth. On warm days raise the humidity.
• August: Growth: new shoots appear. Keep feeding.
• September: Ease off feeding. Let the nights become cooler.
• October: Cool nights (10–13 °C) to set buds. Do not move the buds any more.
• November: Flowering begins. Keep away from radiators.
• December: Flowering. Bright and cool, water moderately.

Did you know?

• The name Paphiopedilum comes from Paphos, the city of Venus, and the Greek pedilon, ‘sandal’: literally Venus’s slipper.
• The rounded pouch works as a trap: an insect slides in and can only leave through a narrow exit past the pollen mass, which is how pollination happens.
• All wild Paphiopedilum are protected under CITES (Appendix I). Only buy plants that were raised in a nursery.