Dead heading is the act of removing spent flowers from a seasonal plant. When a flowering shrub or perennial is producing many flowers the plant is putting all of its growing energy into flower production. Once it is done flowering it returns to more leaf and root growth. Some plants need to be dead headed to continue blooming ( roses & dahlias) and sometimes it is best to dead head as some flower buds will attract bugs ( rhododendrons & azaleas ). Usually we deadhead to clean up the plant as our eyes are always drawn to whatever is dead in the garden. It often signifies the end of that particular plant’s seasonal show and time to focus on the other flowers coming into bloom. Iris and Peonies have beautiful and interesting flowers and foliage so once they are done flowering you can dead head them but their foliage still serves a purpose in the garden.