Re-evaluating the role of herbicides in contemporary urban horticulture

Herbicides provide an inexpensive way of controlling weeds in woody vegetation and result in increased plant vigour and survival rates. They are also a potential threat to the environment and, in many areas, the development of resistant weed biotypes has reduced their value. In Britain and Ireland, land managers are increasingly caught in the dilemma of having to cut costs at a time when public opinion against the use of pesticides is increasing. Some managers no longer use herbicides while others remain dependent on them. There is a general trend away from the use of soil-acting, residual herbicides towards rapidly biodegradable translocated types. There is also increasing interest in the use of non chemical methods of control, such as mulches, and in plant associations that need little or no herbicide use. At the same time, more detailed information on the behaviour of herbicides in soil, air and water is resulting in safer practices and lower residues in the environment. Accordingly, as financial resources available to managers decline further, herbicides are likely to continue to play a valuable role as a component in integrated vegetation management although they cannot be regarded as a general panacea.