Hedge shears are used to cut through the soft, non-woody stems of plants. There are just three situations in which you need to use them: Maintaining a formal hedge, Cutting back perennials, Yearly taming or deadheading. Hedge shears absolutely cannot cleanly or efficiently cut through wood, even thin wood. Using shears to do this not only causes unhealthy cuts to the plant but damage to the blades of the shears.