Abstract We describe six experiments set up at four regional locations in Great Britain, in 1993 and 1994, to examine the impact of control treatments on bracken and associated vegetation. Present discussion is limited to the effects of treatments on bracken frond variables (density, length and dry mass). These variables would be used by a land manager to judge the extent of infestation and the efficacy of control methods. Results of statistical analyses are reported for the period 1994 to 1998, inclusive. The treatments showed great variability in effectiveness between both sites and years. Great inter-regional differences were seen, but stands at sites within a short distance of each other also varied in their response to treatment. Meso- and micro-climatic differences are suggested as possible causes, together with stand growth phase and genetic effects. The most effective treatments in the short-term were found to be combinations of cutting and herbicide spraying, applied once. Annual cutting usually gave a better result in the longer term. All treatments had greatly improved effects when combined with a follow-up application of herbicide several years after commencement. A number of recommendations are given for management, such as best methods for short- and long-term results. Systematic monitoring is urged as changes in frond density, for example, may reveal the extent of the problem for control at a particular site.