Ornamental grasses are popular in many colder hardiness zones for their resilience to cold temperatures and aesthetic value throughout fall and winter seasons.Almost all ornamental grasses are perennials, coming up in spring from their roots, which have stored large quantities of energy, and in fall or winter go dormant.Deer grass (Muhlenbergia rigens) and canyon prince wild blue rye (Leymus condensatus) are popular in larger settings, natural landscaping, and native plant gardens.Many Miscanthus and Pennisetum species flower in mid or late summer, and the seed heads are long lasting, often remaining well into the winter.Some Stipa species flower in the spring, the inflorescence standing almost two metres above the clumps of leaves, and again the seed heads last late into the winter.