Chemical biology influences many aspects of plant growth and development, not least because many signalling components directing such processes comprise small, organic compounds (e.g. plant hormones) that can be chemically synthesised. This month‘s Special Focus Issue, organised by Toshinori Kinoshita, Peter McCourt, Tadao Asami and Keiko Torii (see pp. 1483–1486), highlights how chemical biology continues to be applied to studies on classical hormone signalling, as well as to new emerging research into peptide-receptor pairing, stomatal responses, and plant immunity.