page_title: Cypripedium acaule
section_title: Cultivation
hierarchical_section_title: Cypripedium acaule / Cultivation
caption_attribution_description: English: Cropped plate of Cypripedium acaule. Two-Leaved Lady's Slipper, Moccasin Flower, or Pink Lady's Slipper. Plate No 192, appearing in Volume 6 of Curtis's Botanical Magazine.
context_page_description: Cypripedium acaule is a species of flowering plant in the orchid family Orchidaceae. The genus Cypripedium is one of the five genera in the sub-family Cypripedioideae, commonly known as lady's slipper orchids. First described in 1789 by Scottish botanist William Aiton, C. acaule is commonly referred to as the pink lady's slipper, stemless lady's-slipper, or moccasin flower. The pink lady's slipper is the provincial flower of Prince Edward Island, Canada, and the state wildflower of New Hampshire, United States. Its close relative, Cypripedium reginae, is the state flower of Minnesota.
context_section_description: Seed germination labs have increased the commercial availability of C. acaule, although it still tends to be less commonly available than other Cypripedium species and hybrids. This is primarily due to the extra care that must be provided if the growing site is not naturally suitable for in-ground cultivation. This plant grows in soils below a pH of 5, often at 4–4.5. At this high acidity soil fungus is suppressed, and C. acaule can thrive. There is even evidence that it is partially myco-heterotrophic, parasitizing fungus that attempts to invade its roots. However, in soils above pH 5, soil microbes become more than C. acaule can manage, and the plants rot. Seedlings germinated in a sterile environment can grow and thrive in a much higher pH than 5, but must be grown below 5 if removed from the sterility.
  For artificial cultivation, container culture is a must, and the growing medium must be naturally acidic. Additionally, all other soil additives must be devoid of any calcium that could buffer the pH to above 5. High quality peat moss or pine duff work well, and pH neutral perlite can be added to improve porosity. Due to the risk of calcium bicarbonate, tap water is unsuitable. Rainwater or distilled water mixed with 2 ounces (57 g) of vinegar per gallon will assure that a reliably high acidity is maintained in the growing medium. Give bright dappled shade or morning sun. Sink pots in winter or store in a cold frame for insulation. Given these conditions, C. acaule can thrive indefinitely, but it will always require much more maintenance than other species/hybrids that can be grown in a wider pH range.
caption: A drawing published in Curtis's Botanical Magazine in 1793
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