Function

• True lilies with origins in lands with pronounced cold or dry winters, naturally diminish their foliage in fall or winter. This dormancy protects the plant from freezing, conserves food energy and often the cool soil temperatures initiate flower bud formation within the bulb. This process is called vernalization.
  
  

Significance

• Without an annual dormancy, especially when sunlight energy is weak and temperatures cold, a lily plant doesn't have enough food to maintain itself. The dormancy orients the plant to recognize seasonal triggers to later sprout in spring when warmth returns.
  
  

Effects

• Since lilies naturally go dormant, florists take advantage of this time to lift bulbs and transport them. This allows greenhouse gardeners to force, or grow the bulbs out of season after the dormancy, regardless of time of year the dormancy was induced.