There are a number of estimates of the land area that could potentially be dedicated to perennial energy crops such as short rotation coppice (SRC) willow and miscanthus in the UK, but little is known about how farmers will respond to the opportunities presented by these relatively novel crops. Perennial energy crops face competition from other, arguably more flexible, uses of farmland, and if not seen as attractive propositions to individual farmers, they will not be grown. Farmers' decisions are therefore a key constraint on potential supply. This paper reviews the policy background and considers whether policy is based on any consideration of likely supply response, before presenting outcomes of focus groups composed of farmers who already grow or are considering growing perennial energy crops. There appear to be a number of barriers to adoption. In addition to concerns over the security of contracts, the current high wheat price increases the opportunity cost of committing land to perennial energy crops. There are also worries about the impact of willow roots on field drains and the cost of returning the land to other uses. This paper outlines a number of issues of importance to policy makers and suggests future research needs. (C) 2008 Elsevier Ltd. All rights reserved.