Thyme (Thymus vulgaris) is both ornamental and edible and remains green year-round. In summer the small flowers attract bees and other beneficial insects to your garden. Thyme grows in U.S. Department of Agriculture plant hardiness zones 5 through 9. Depending on the variety, it may have an upright, mounded habit or it may grow as a creeping ground cover. The lower sections of thyme stems tend to become woody with sparse foliage. Rejuvenation pruning can force a new flush of dense top growth that helps the plant remain full and lush.
Mix together 1 part bleach and 9 parts water in a container. Soak the bypass pruning shears in the solution for five minutes. Rinse the shears with water before you use them.
Cut back each stem to the nearest healthy portion using bypass shears. Cut back the thyme in late winter or early spring to remove any dead or damaged stems.
Trim the thyme back by one-third to one-half its height in midsummer if it is producing weak or lanky growth. Shape the thyme lightly as you prune it into a fuller, more mounded shape. Prune so the lower portion of each stem still has some leaves on it.
Prune out dead or damaged stems throughout the growing season, removing these at their base. Cut back overgrown stems to the desired height so the thyme maintains a mounded shape.