Cypripedium calceolus

By Roslyn Duffus

I have always loved spring woodland flowers and the ladys slippers in particular. I used to scan our property in the spring looking for any that showed up and carefully marked them to protect them from damage and I went on daily inspections to admire them in season. After our move to Waverley, we found that we were lucky enough to have several of the native pink Cypripedium acaule on the property. It is always tricky to move this species and I have done so only when the plants have been threatened by development, were on private property and then only with the owners’ permission.

When I attended the North American Rock Garden Societys winter study weekend in Toronto in 1998, I picked up a catalogue from Lost Horizons Nursery in Acton, Ontario, and found that they had C. calceolus available from nursery grown stock. So I ordered one and then picked up two more when traveling in Ontario in 1999. C. calceolus, the yellow lady’s slipper, is easier in cultivation than our local pink lady’s slipper which tends to die out in a few years if its requirements are not met. I provided a fertile moist humus rich soil, dappled shade and a little lime, with some chunks of gypsum gravel which I happened to have on hand. I try to mulch with composted leaf mold annually. These plants have all done well and each has developed four to six growing points. This spring I bravely dug up one of these clumps and broke it apart into separate parts. Each growing point was left with several long slender rhizomes which were replanted just under the soil surface. This was a little scary but they all survived the summer even if they were a little sulky and I hope to see them return in the spring in good spirits.

This is a lovely plant with its bright yellow pouch and slightly twisted brownish tepals. It grows about 16 inches tall and as wide with time, and is a worthy addition to the garden.