Showy Lady's Slipper

About

Showy lady’s slipper is one of the largest and most striking hardy orchids. It produces large flowers with a rounded, inflated pouch of soft rose-pink set against white sepals and petals. From a leafy clump of broad, hairy, pleated leaves it can lift stems knee-high or more, each carrying one or two flowers in early summer. A settled colony in a cool, wet, limy spot is a serious garden plant rather than a casual pot orchid.

It is a hardy wetland orchid from eastern North America, growing in cool, wet but airy fens, seeps and damp woodland edges over limy ground. It is very cold-hardy, dying back to a rootstock each winter and needing that cold dormancy to flower. The difficult part is the root run. It needs cool, constantly moist to wet, humus-rich, alkaline ground that never turns warm, dry, acid or stagnant.

It shares the lady’s slipper reputation for difficulty, and the key is its wetland home. It needs cool, wet, limy and airy ground in part shade. Grown from nursery-raised stock in those conditions, never dug from the wild, it can establish and slowly increase. It needs time and the right site.

Appearance and character

The leaves are broad, oval, hairy and strongly pleated, several up each stem, forming a tall, leafy clump that dies back to the ground each autumn.

The flowers are large and showy, with a rounded, inflated pouch of soft rose-pink against pure white sepals and petals, one or two to a stem in early summer.

It grows as a slowly spreading clump from a rootstock, building into a colony over years. It is very cold-hardy and rests dormant through the coldest winters.

Its hairy leaves and stems can irritate sensitive skin, like the other lady’s slippers, so wear gloves if you react easily.

Where it is from

Cypripedium reginae grows in eastern North America, in cool, wet but airy fens, seeps, wet meadows and damp woodland edges over limy, humus-rich ground. It is a plant of cool wetlands, not of dry or acid soil.

Give it cool, constantly moist to wet, humus-rich, alkaline ground that stays airy instead of stagnant. It also needs part shade and a cold winter dormancy. It cannot take heat, drought, acid soil or a warm, stagnant root run.

How it grows

It grows in spring and early summer, producing leafy stems and large slipper flowers. Through summer it builds its rootstock in cool wet soil, then dies back in autumn and rests cold through winter. That cold dormancy is essential, and a colony builds slowly over years.

Grow it in cool, wet but airy, humus-rich, limy soil, in part shade, by a pond edge, bog garden or deep wettable bed. Keep the root run constantly moist to wet with rainwater or lime-bearing water. Plant only nursery-raised stock.

Keep it cool and airy at the root, never letting the wet become stagnant, and let it die back and rest cold over winter. Disturb it as little as possible, and let the colony build over years.

Propagation is by careful division of an established clump in early autumn, or from seed by specialists.

Through the seasons

Spring brings the leafy shoots and, into early summer, the large pink-and-white flowers. Keep the root run cool and constantly moist.

Summer is when the plant builds its rootstock in cool wet soil. Keep it cool, moist to wet but airy, and lightly shaded.

Autumn is when the foliage dies back. Ease off the wet as it goes dormant, keeping it just moist.

Winter is its cold dormancy, which it needs to flower. Keep it cold and only just moist, never warm.

Care difficulty

This is a difficult orchid because it needs a very specific site. It needs cool, wet but airy, humus-rich, limy ground in part shade, with a cold winter dormancy. It cannot take heat, drought, acid soil or stagnant wet. In a bog-garden or pondside spot that stays cool, wet, airy and limy, nursery-raised stock can grow and slowly increase, but the conditions have to be right.

Watering

Keep the root run constantly cool and moist to wet through the growing season, using rainwater or lime-bearing water. It comes from wet, limy fens and should not dry out in growth.

The wet must stay airy, not stagnant, so an open, humus-rich, free-draining but constantly moist medium suits it best. Stagnant, airless wet rots the crown. Ease off as it dies back, keeping it just moist through cold winter dormancy.

Warning signs, diseases and pests

Warm or stagnant, airless wet rots the crown and is the commonest cause of failure. Keep the root run cool, wet but airy, and never let it turn warm or stagnant.

Slugs and snails graze the emerging shoots and flowers, so protect the young growth. Failure to establish usually means the soil was too warm, too dry, too acid or too stagnant for this cool, wet, limy-loving orchid.

Handle it with gloves if your skin is sensitive, since the glandular hairs can cause a contact rash.

Growing environment

Part shade to dappled sun suits it, more open than the woodland lady’s slippers since it grows in fens and wet meadows, though it still dislikes full, hot sun. Deep shade stops it flowering.

It is very cold-hardy and needs a cold winter dormancy, so it is a plant for a cool, wet garden spot, bog garden or pond edge, never a heated room. High humidity and cool air suit it.

Grow it in a cool, wet but airy, humus-rich, limy soil in part shade, by water or in a wettable bed, from nursery-raised stock only.

Feeding

Feed very sparingly in the growing season with a very dilute balanced feed, since it is adapted to lean, cool wetland soil. A humus-rich, limy medium and a leaf-mould mulch provide most of what it needs.

Give nothing in dormancy. The right cool, wet, limy root run matters far more than feeding.

Troubleshooting

It failed to establish or return. Usually the soil was too warm, too dry, too acid or too stagnant. Give it a cool, wet but airy, humus-rich, limy root run in part shade, and plant nursery-raised stock without disturbing the roots.

The crown rotted. Warm or stagnant, airless wet. Keep the root run cool, wet but airy, and never let it turn warm or stagnant.

Can I dig one up from the wild? No. Wild lady’s slippers are protected and rarely survive transplanting. Always buy nursery-raised, propagated stock.

Why does it need limy, wet soil? It is a fen and wet-meadow orchid, adapted to cool, wet, alkaline ground, so it cannot be grown in dry or acid soil; it needs a cool, wet, limy root run.

How is it different from the yellow lady’s slipper? It is taller, with large pink-and-white flowers, and wants wetter, more open, limy ground, where the yellow lady’s slipper has yellow slippers and prefers cool, moist woodland. Both are hardy terrestrial orchids needing a cold winter.