Information from a vegetation survey comprising all the major habitats of the Sheffield region in northern England has been examined to identify the plant species that have most effectively colonized spoil habitats. The most frequent components of spoil vegetation are perennial herbaceous species, many of which are grasses of widespread occurrence in the region as a whole. A distinctive group of colonists within the spoil flora consists of species that exploit substrates, such as cinders and lead-mine spoil, which are inhospitable to the majority of plants and of scattered occurrence in the landscape. These specialist colonizers are mainly uncommon dicotyledons; many are ephemerals and most depend upon efficient distribution by wind or by man’s activities. Published sources and data from laboratory screening experiments have been used in an attempt to recognize general characteristics of spoil colonizers. A high proportion are perennial plants of base-rich soils. The majority display the potential, as seedlings, for moderate to rapid rates of dry matter production and have 2 nuclear DNA amounts concentrated in the range 2.0-10.0 pg. Plants colonizing spoil tend to exhibit an extended flowering period and include many species with relatively small seeds, but they are widely divergent with respect to flowering season, breeding system, capacity for wind dispersal, dormancy of freshly collected seeds, seed bank characteristics and germination responses to temperature and irradiance. It is concluded that the characteristics of spoil colonization in the Sheffield region are broadly consistent with the ‘infection pressure’ theory of Salisbury (1953, in The changing flora of Britain (ed. J. E. Lousley), pp. 130-139) and are but one symptom of massive changes occurring throughout the landscape under the impacts of disruptive land-use and eutrophication. These changes are predictable by reference to the C-S-R theory of primary plant strategies and to recent evidence relating strategy theory to patterns of ecological specialization and evolutionary advancement within the angiosperms.