The urn orchid grows from a subterranean pseudobulb. Each pseudobulb produces a determinate shoot, that is, it sends up a single stem that produces four or five plicate (pleated) leaves and terminates with the inflorescence.   

After flowering, the shoot will live out the season. The photosynthates (sugars, starches) produced in the leaves provide energy for the production of more pseudobulbs. In autumn, the shoot dies back and the urn orchid goes dormant. Next spring, the new pseudobulbs will produce shoots.

For more northerly locations or where winter does not chill, the urn orchid can be cultivated in a pot. And it seems to do best when slightly pot-bound. When actively growing, the urn orchid does not really care how high temperatures may get; it will bloom on the new growth in late spring.  But to bloom, the urn orchid must have vernalization--a winter dormancy in a location where it is chilled, but not hard frozen.

 

(Compiled from: Hortus Third, Staff L.H. Bailey Hortorium, NY State College of Agriculture and Life Sciences, Cornell University, Macmillan, NY, 1976; A-Z Encyclopedia of Garden Plants, C. Brickell and J.D. Zuk, eds., American Horticultural Society, DK Publishing, 1996; L. Swanson, pers. comm. and “Bletilla striata”, Plant Finder, Kemper Center for Home Gardening, Missouri Botanical Garden)