The hosta is a common garden perennial grown for both its flowers and glossy, variegated foliage. They are commonly used to add texture and color to shady areas of your backyard, as well as in potted gardens. Hosta plants are hardy down to USDA zone 3. Pruning or trimming is rarely required except to remove dead flowers and to prepare the plant for winter in cold climates where frost occurs.
Deadhead the hosta plant. Cut off the hosta's flower stalk as soon as the flowers have withered. This encourages the hosta to continue to produce new flowers.
Prune back the hosta plant to prepare it for winter. Wait until after the first frost in your area when the hosta plant starts wilting. Use a ruler and measure 6 inches from the base of the plant.
Trim back all foliage beyond the 6-inch mark. This helps keep the plant from being burned severely during the winter's colder temperatures. Pile mulch or hay over the plant after trimming it.