Species Orchid, Eastern Fairy Slipper, Bulbed Calypso

Calypso bulbosa

Family: Orchidaceae (or-kid-AY-see-ee) (Info)
Genus: Calypso (kal-IPS-oh) (Info)
Species: bulbosa (bul-BOH-suh) (Info)
Synonym:Cypripedium bulbosum
Synonym:Cytherea bulbosa


Alpines and Rock Gardens



Foliage Color:

Unknown - Tell us

Bloom Characteristics:

Unknown - Tell us

Water Requirements:

Average Water Needs; Water regularly; do not overwater

Where to Grow:

Unknown - Tell us


under 6 in. (15 cm)


24-36 in. (60-90 cm)


USDA Zone 4a: to -34.4 C (-30 F)

USDA Zone 4b: to -31.6 C (-25 F)

USDA Zone 5a: to -28.8 C (-20 F)

USDA Zone 5b: to -26.1 C (-15 F)

USDA Zone 6a: to -23.3 C (-10 F)

USDA Zone 6b: to -20.5 C (-5 F)

USDA Zone 7a: to -17.7 C (0 F)

USDA Zone 7b: to -14.9 C (5 F)

USDA Zone 8a: to -12.2 C (10 F)

USDA Zone 8b: to -9.4 C (15 F)

Sun Exposure:

Partial to Full Shade


Handling plant may cause skin irritation or allergic reaction

Bloom Color:


Bloom Time:

Late Winter/Early Spring

Mid Spring

Blooms all year



Other details:

Unknown - Tell us

Soil pH requirements:

6.1 to 6.5 (mildly acidic)

Patent Information:


Propagation Methods:

By dividing rhizomes, tubers, corms or bulbs (including offsets)

From seed; germinate in vitro in gelatin, agar or other medium

Seed Collecting:

Unknown - Tell us


This plant has been said to grow in the following regions:

Chugiak, Alaska

Crescent City, California

Englewood, Colorado

Careywood, Idaho

Cottage Grove, Oregon

Lebanon, Oregon

Lostine, Oregon

Salem, Oregon

Anacortes, Washington

Belfair, Washington

show all

Gardeners' Notes:


On May 31, 2010, paulownia_lover from Beaverton, OR wrote:

The Calypso Orchid grows wild on Decatur Island in the San Juan Islands of Washington State. It's usually found in duff and moss a foot or two inside the edge of fir forest, often along dirt and gravel roads with unimproved ditches. The island's old-timers called them Lady Slippers, and the story goes that in the first half of the 20th century, the island's dentist would go out on his wife's birthday in March to pick her a large handful. The orchids are harder to find now. As the island's population has grown, the orchid's population has declined.


On Aug 22, 2008, buggycrazy from Lebanon, OR (Zone 7b) wrote:

slugs, racoons and BIRDS devour these so they should be screened and slug baited all year. Extremely drought tolerant in the soil, should be kept barely moist if in a container. Also avoid fertilizers and fungicides as these may kill the symbiotic fungi that grows with it, if grown in containers a good topdressing of woods duff every year in the summer when dormant is recommended.


On Dec 18, 2004, JerryMurray from Belfair, WA wrote:

In my many travels as a forester through the Pacific Northwest I have encountered fairy slipper numerous times and in diverse habitats. Most populations I saw contained light purple to dark purple forms of the species. In 1980 I encountered an all-white individual growing in moss in a British Columbia, Canada, yellow cedar forest, and a friend found an albino population in northern California in 2001. One author shows a photograph of a yellow-flowered clump located in the Olympic National Forest in Washington state. Other locations I have seen Calypso include a fairly dry brushy area along the Kootenai River, Montana, just south of the dam; and the Blue Mountains of Washington, where the species grew directly in moist dense moss along a streamside dominated by a closed-canopy Picea englem... read more


On Jun 9, 2004, GeorgesLess from Fort Smith
Canada wrote:

I live in Fort Smith, Northwest Territories X0E 0P0, Canada 6000'N, 11158' W
Calypso Orchid Calypso bulbosa grows here in the Boreal forest and I have been lucky enough to have taken some nice pictures of it.

In the specific place where I found it... there were seveal other groupings of the plant... all growing in the wild.

We are just on the edge of the Wood Buffalo National Park on the shore of the Slave River.

Wood Buffalo Park is a very specific almost micro climate area with many unique features... like the most northern nesting point of the White Pelican and the Whooping Crane.


On Jun 7, 2003, seb_number1 wrote:

I'm french, And I grow C.bulbosa (origin: Canada) since 9 months. The plants (6 plants) seems to like spring potting, just when the plant has developed a single leaf, at this time, the roots are white and the corm is billowy.
I use a personal potting mix which is made of charcoal (1/10), fine quartz sand (2/10), pine bark and needle humus (4/10), and leaf humus (3/10).

All this elements must been mixed together, I prefer sterilize the mix (in microwave, maximun power during 15 min) because the fungus who lives on Calypso roots needs no more other concurrents fungus species.
Use the mix after 2 days !
It's my opinion, try an other way if you want...

The plants need full shade nevertheless a bright place.
A location under trees seems ... read more


On Apr 7, 2003, dorr wrote:

I just located this splendid orchid in the Pacific Northwest; sea level; on an evergreen forest, floor. At the time the high temperature for the day was seasonably low ~43F (although we've had a very mild spring); windy with showers. The orchid was in full bloom and quite a shock to stumble on. Most sources show its blooming period as May through July and yet when I found the plant, while in full bloom, it was the first week in April! I saw no others either associated with it in a cluster nor anywhere while on my walk. There were 2 leaves and a single stalk.


On Oct 7, 2001, Baa wrote:

Terrestrial orchid from North America, Europe and Asia. Has a single, pleated, oblong shaped leaf up to 8 inches long wich grows from a corm. Flowers are 1-1 inches and pinkish purple, large slipper shaped lip which is white spotted purple, pink or yellow.

Flowers in May. Enjoys rich, moist soil enriched with leaf mold or bark chips in a neutral to acid soil in partial shade.

In frost prone areas grow in a cold shaded greenhouse, in warmer regions grow in a woodland or bog garden.

Divide corms very carefully to propigate.