Extended areas of new crops to produce not only food, but also energy and materials, was one of the visions when the EU agricultural policy was reformed in 1992. However, this vision remains unfulfilled. The perennial C4 grass Miscanthus, originating from eastern Asia, was one of the crops that caught major interest as a potential biomass crop due to its high productivity even in cool northern European conditions (Beale & Long, 1995). However, even very large initial programmes on Miscanthus were conducted almost exclusively within one genotype, namely the sterile, triploid, interspecific hybrid M. × giganteus, and ran into significant problems of low first winter survival and prohibitive high costs of vegetative establishment. Thus, despite the many encouraging results on Miscanthus productivity (van der Werf et al., 1993), environmental acceptability (Christian & Riche, 1998) and harvest and storage suitability (Venturi et al., 1998), it is clear that the introduction of a new crop into agriculture is not simple, and that basic ecophysiological understanding is important to support commercial exploitation. The results in this issue from Clifton-Brown & Lewandowski (see pp. 287–294) contribute to this vital, basic understanding, revealing that low frost tolerance of M. × giganteus rhizomes is probably the cause of low winter survival in cool parts of Europe, but that within the genus Miscanthus better frost tolerance exists.