Cypripedium Xandrewsii. This is the natural hybrid of C. candidum and C. parviflorum var. makasin.  The flowers open yellow but turn white in a day or two.  The hybrid is taller and the flowers have darker tepals than C. candidum.  The plant is native to the prairies of the Midwest and enjoys bright sun in early spring but needs light dappled shade during hot summer weather.  The plant likes moist, calcareous soil and benefits with the occasional addition of horticultural lime to the planting mix to keep the pH slightly above neutral.  Zones 3-5 and northern Zone 6.

Cypripedium californicum.  The California lady's-slipper is native to northern California and a small area in southwestern Oregon.  The plant grows into large clumps with several  flowers per stem, and the flowers are quite fragrant.  We have recently had excellent success growing seedlings in a purely inorganic mix of 1 part Turface® MVP to 2 parts perlite.  When fertilized lightly with each watering, this species grows quite rapidly.   This plant likes fairly bright conditions: 40-50% shade cloth.  Zones 7-9, possibly also Zones 6 and even 5 with winter mulching.
 

Cypripedium Carol Ilene (C. pubescens X C. hotei).  We don't grow many hybrids, but because this one is named for my mother, I can't resist.  This plant grows rapidly in a mix with a high percentage of perlite.  Zones 3-5, possibly 6.

Cypripedium Gisela (C. parviflorum X C. macranthos).  This hybrid is very vigorous and will even grow in a light loam although we recommend a mix with lots of perlite.  Zones 3-5, possibly 6. 

Cypripedium guttatum.  Also known as the "spotted lady's-slipper," this wonderful little plant grows up to a foot tall and sports flowers with purplish-red blotches.  In suitable conditions the creeping nature of the rhizome results in a spreading of the plant almost like a ground cover.  C. guttatum is native to Alaska and is widespread in Russia and other colder parts of Asia.  Cold soil is a fundamental requirement for growing this plant.  We recommend locating it on the north side of a building where there is no direct sun during the hot part of the day.  Our plants thrive in beds with a mix of 1 part leaf mold to 2 parts sand.  Zones 2-4, and the cooler parts of Zone 5 if grown in the shade. 

Cypripedium kentuckiense.  The southern lady's-slipper is the largest-flowered of all the Cyps. Fortunately, it is also one of the easiest to grow.  The natural range of this plant is from Kentucky south to Louisiana, but it can be grown successfully outdoors as far north as Vermont, Wisconsin, and even northern Minnesota if protected with heavy mulch in winter.  This species likes a shady site in the south but prefers increasingly open conditions northward.  In culture, C. kentuckiense thrives in a sandy mix.  Zones 3-7.
 

Cypripedium macranthum.  This Asian species is quite variable in color ranging from magenta through light pink.  The plant in the photo has parentage from the Lake Baikal region of Siberia, but we also have breeding stock from the Russian Far East and Japan.  Please enquire about the provenance and color of the plants we currently have in stock.  This species requires a very freely draining mix with large particle size and relatively little organic matter.  We have been using a mix that is mostly perlite.  Zones 2-5.
 

Cypripedium parviflorum var.  makasin.   The northern small-flowered yellow lady's-slipper.  This is a relatively easy to grow and very rewarding plant for a moist woodland garden.  The plant prefers high open shade but a little direct sun in early morning is welcomed.  Both the small- and large-flowered yellow lady's-slipper grow into large clumps when cultivated under favorable conditions.  Zones 2-6.
 

Cypripedium parviflorum var. pubescens. (Formerly Cyp. calceolus var. pubescens.)  This is the large-flowered yellow lady's-slipper. This plant is one of the easiest of all the lady's-slippers to grow and thrives in woodland gardens with open shade but tolerates early morning sun.  This plant can withstand cold northern winters even when there is little snow on the ground.  This is the best plant for people inexperienced in Cypripedium culture.  Zones 2-6.
 

Cypripedium reginae.  The queen's or showy lady's-slipper. Large size, spectacular beauty, and relative ease of culture combine to make this species one of the most desirable for moist woodland gardens.  The roots of this plant should never be allowed to dry out, but the soil should not remain wet either.  This species must have a little direct sun in order to flower but enough shade during the hot part of the day that the soil does not get too warm.  Zones 2-5 and cooler parts of Zone 6.
 

Cypripedium reginae forma albolabium.  White-flowered form of the showy lady's-slipper.  These plants are identical to the normally colored form but have blooms with a pure white lip.  There is no pink whatsoever.  Forma albolabium seems just as vigorous and cold hardy as the normally colored plants.  Zones 2-5 and cooler parts of Zone 6.
 

Cypripedium tibeticum.   This species resembles Cyp. macranthos but is even larger-flowered!    A critical factor for growing Cyp. tibeticum is moisture;  the plant must be kept moist all summer but not allowed to be in any standing water or soggy soil  in the winter.  Puddles from melting snow are lethal.  Zones 3-5.  Winter mulching is advisable in Zones 3-4.  The plant can be grown in a climate with a winter as warm as Zone 8 provided summer summer temperatures are cool.
 

Cypripedium yatabeanum. Another plant from Alaska and colder parts of Asia that resembles Cyp. guttatum but is much less colorful.  The plant in the photo is from Japan.  Like Cyp. guttatum, Cyp. yatabeanum requires cool growing conditions during the summer.  The north side of a building offers a good location.  Cyp. yatabeanum may be somewhat more tolerant of brief periods of high summer temperatures as  it is grown very successfully in Germany.  Zones 2-5.  Possibly cooler parts of Zone 6.