Cypripedium spp., lady's slipper
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Perennials

Cypripedium spp.

lady's slipper

OrchidaceaeNorth America, Europe, Asia

At a Glance

TypePerennial
HabitClumping
FoliageDeciduous
Height8–24 inches (20–60 cm)
Width8–18 inches (20–45 cm)
Maturity4 years

Growing Zones

USDA Hardiness Zones

3 - 8
Zone 3
Zone 4
Zone 5
Zone 6
Zone 7
Zone 8
These zones indicate the coldest temperatures this plant can typically survive.
Frost Tolerancehardy

Key Features

Attracts Pollinators
Native to North America
Maintenancehigh

Overview

Cypripedium, commonly called lady's slipper orchids, is a genus of approximately 58 species of terrestrial orchids in the family Orchidaceae, distributed across temperate and boreal regions of North America, Europe, and Asia. Plants grow from short, stout rhizomes, producing erect stems with two to several large, pleated, parallel-veined leaves and one to a few showy flowers, each featuring a distinctive inflated pouch-like lip (labellum) that functions as a temporary insect trap to ensure cross-pollination. Flower colors vary by species from yellow and green to white, pink, and deep maroon. Most North American species are protected; collecting from the wild is illegal in many states and provinces. Native Pacific Northwest species include Cypripedium montanum (mountain lady's slipper), found in open coniferous forest and woodland edges. Cypripedium species are notoriously difficult to cultivate and require specific mycorrhizal fungal associations to germinate and establish; garden cultivation is most successful with nursery-propagated stock. Plants are long-lived when successfully established, with individual plants known to persist for decades.

Native Range

The genus Cypripedium is native to temperate and boreal regions of the Northern Hemisphere. North American species range from the eastern woodlands (Cypripedium acaule, C. reginae) to the Pacific Northwest (C. montanum, C. californicum). European species include Cypripedium calceolus, which is critically endangered across much of its range. Asian species are particularly diverse in China and the Himalayas. Several Pacific Northwest native species are protected under federal and state law.

Suggested Uses

Lady's slipper orchids are specialized plants for naturalistic woodland gardens, native plant gardens, and shaded borders where conditions can closely approximate their natural habitat. Cypripedium montanum is the most appropriate species for Pacific Northwest native plant landscapes, paired with sword fern, trillium, and native violets in open conifer woodland settings. The plants are best treated as specimen or accent plants rather than mass plantings, given their cultural demands and conservation status.

How to Identify

Lady's slipper orchids are identified by their distinctive inflated, pouch-like lip petal (labellum) — the slipper — paired with spreading, often twisted lateral petals and sepals in contrasting colors. Leaves are large, broadly ovate to elliptic, prominently pleated with parallel veins, and arranged alternately on the stem. Plants grow from short rhizomes just below the soil surface. The combination of pleated parallel-veined leaves and the unique slipper-shaped pouch is unmistakable among Pacific Northwest native plants.

Appearance

Size & Dimensions

Height8" - 2'
Width/Spread8" - 1'6"

Reaches mature size in approximately 4 years

Colors

Flower Colors

yellow
white
pink
maroon

Foliage Colors

green

Fall Foliage Colors

yellow

Bloom Information

Bloom Period

~4 weeks
J
F
M
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M
J
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S
O
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SpringSummer
Lady's slipper orchids bloom in late spring to early summer, typically May through July depending on species and elevation. Cypripedium montanum, the Pacific Northwest native, blooms from May to July in open coniferous forest sites. Individual flowers are long-lasting, persisting for two to four weeks on the stem. Plants may take five to ten years from seed to first flower under natural conditions; nursery-grown plants typically bloom in two to three years after planting.

Detailed Descriptions

Flower Description

Yellow, white, pink, or maroon with contrasting pouch, depending on species

Foliage Description

Medium green, broadly ovate, pleated with parallel veins

Growing Conditions

Sun Requirements

Partial Shade
Full Shade
Requires 1-4 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight

Soil Requirements

pH Range6.0 - 7.0(Neutral)
357912
Soil Types
loampeat
Drainage
moist

Water & Climate

Water Needs

Medium

Frost Tolerance

hardy

Time to Maturity

3–5 years

Care & Maintenance

Care Guide

Cypripedium are among the most demanding ornamental perennials to cultivate and should only be purchased as nursery-propagated divisions or seedlings — never wild-collected. Plant in dappled shade in cool, well-drained, humus-rich soil with near-neutral pH; most North American species prefer slightly acidic to neutral conditions (pH 6.0–7.0). Good air circulation and consistent moisture without waterlogging are essential. Avoid fertilizing; excess nutrients, particularly nitrogen, are harmful. Do not disturb roots once established. In Pacific Northwest gardens, situate under open deciduous or mixed canopy that provides light shade without root competition. Mulch lightly with leaf mould to maintain moisture and soil temperature.

Pruning

No pruning is required. Allow foliage to yellow and die back naturally in autumn; remove dead leaves only after fully senescent. Do not cut back green foliage prematurely as this reduces the plant's ability to store energy for the following season. Division is rarely necessary and should be attempted only with extreme care in early spring before growth begins, retaining as much root and mycorrhizal zone as possible.

Pruning Schedule

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fall

Maintenance Level

high

⚠️ Toxicity Warning

Unknown
Cypripedium spp. (lady's slipper) - Identification & Care Guide | PlantRef