Transplantation of vegetative diaspores and adult thalli of various threatened foliose lichens such as Sticta sylvatica, Lobaria pulmonaria, and Parmotrema crinitum was found to be a successful approach for in situ conservation and the successful establishment of additional populations of these species. Immobilization of diaspores on artificial and natural substrates appears to be a major limiting factor in this reproductive process. Only when isidia of P. crinitum were carefully placed between the fibres of surgical gauze was there a substantial degree of immobilization of the diaspores which eventually produced anchoring hyphae from the apices of the isidial cilia to improve their attachment to the substrate. Our experiments with L. pulmonaria show that either adult thalli or vegetative diaspores could be used for re-establishment of endangered lichen populations. However, where possible, the non-destructive method of transplanting natural, vegetative diaspores should take priority. In S. sylvatica the duration of the juvenile development from the transplantation of the isidia until the first development of elongate lobules of up to 0.2 mm was found to be 24 months; this is the longest period so far reported for lichens. In S. sylvatica this very slow rate of growth seems to also continue after the development of stratified thalli and even after 4 years the thalli only measured about 3 mm in length. Analysis of permanent plots with juvenile thalli further demonstrated that slow growth seems to be typical for this life stage, making this species very vulnerable to competition, e.g. from bryophytes.