An experiment comparing the fresh and dry matter yields of four willow cultivars (Ulv, Salix viminalis, Jorr, S. viminalis, Tora, S. viminalis x S. schwerinii and Ashton Stott, S. viminalis x S. burjatica) at four planting densities (10,000, 15,000, 20,000 and 25,000 plants ha(-1)) was established within a commercial SRC plantation in northern England. Data are presented for the first cut one year after planting (2001) and for a harvest after one complete growth cycle of three years (2004) and for annual yield production. There were significantly higher yields with increased density, and there were significant differences between cultivars. The cultivar Ashton Stott gave considerably higher fresh and dry yields than Ulv, Jorr and Tora, despite having a lower percentage dry matter content, with annual yields exceeding 10 t oven dry matter ha(-1) yr(--1) at the highest two densities. (C) 2007 Elsevier Ltd. All rights reserved.