As of March 2023 Trees and Shrubs Online contains over 12,000 individual articles on woody plants hardy in the northern temperate zones. The texts are derived from three major sources: the Eighth Edition of Bean’s Trees and Shrubs Hardy in the British Isles (1976–81) together with the Supplement (1988); New Trees: Recent Introductions to Cultivation (2009); and brand new text specially commissioned for Trees and Shrubs Online.
Many groups are still in their Bean format, some combine text from Bean, the Supplement, and from New Trees, and as funding is secured to commission revisions these are brought fully up to date. The following list identifies the major groups that have been fully updated so far. It is updated whenever a new account is published: