Methods for the Efficient Propagation of the Showy Lady's Slipper

We are intensively studying regionally endangered Cypripedium species, or lady's slipper orchids, to build a model for endangered species conservation in New England. To work towards this goal, we needed to efficiently raise thousands of Cypripedium reginae plants to study their in vitro and in situ development, propagation requirements, and habitat requirements. Using axenic seed culture, our team has grown roughly 2,000 seedlings per year since 2011 and currently has about 2,200 seedlings in sterile culture. We have stored about 400 seedlings at 5 °C (vernalized) for between 1-6 months, and initial results indicate seedlings stored in compost survive better than those stored in peat moss. Surprisingly, some seedlings can be vernalized in compost for over 6 months with no evidence of molding or visible deterioration in shoots, rhizomes, or roots. We have successfully grown about 80 vernalized seedlings outdoors in soil over the past two years in an effort to create a model sanctuary. By the fall of 2014, we will have created three additional sanctuaries in the region. We expect our first flowering orchids in the next two years. Our projection is that we will produce 2,000 more seedlings with axenic seed culture by the end of 2014 to provide a constant supply of seedlings for future study. In an effort to increase our approximately 50% survival when moving plants from vernalized conditions to soil, we are testing a variety of hydroponic methods of propagating Cyp. reginae. This would entirely avoid using soil with its multitude of variables. Our first two methods of hydroponic growth, using small pebbles and nutrient liquid medium, failed to maintain the health of any seedlings. We are currently testing a new hydroponics design that uses rock wool, commonly used in commercial hydroponics, and a liquid medium introduced on a timed basis to maintain optimal growing conditions. The primary design challenges to date have been: ensuring liquid medium remains unspoiled; delivering sufficient liquid medium to the plants; matching the inflow to outflow to prevent flooding; and inserting plants into the dense rock wool medium without damaging the seedlings. Our results from experiments on axenic seed culture, vernalization, transplantation to soil, and most recently, hydroponic propagation, will lay the foundation for conservation of other endangered species.