This Red Data Book biennial is primarily a plant of well-drained soils associated with waste ground, tracksides and dry grasslands. Most of its existing sites are on the South Downs in Sussex. At a site near Brighton planning permission was recently granted for a new residential development that would result in the partial loss of a Red Star-thistle population. As part of a mitigation package a translocation exercise is planned to establish a new population of Red Star-thistle close by. As an insurance policy, in case the translocation fails or the plant disappears from the retained parts of the site, we were commissioned to retain a backup population in our rare plants nursery. In addition, seeds were also sent to Kew’s Millennium Seed Bank for long term storage.