Strigolactones are a major class of hormone recently discovered in plants, with similarity to karrikin germination signals and bacterial quorum sensing signals. Strigolactone biosynthesis increases when conditions become poor, such as low nutrients, drought, salinity, pathogen attack or shading from other plants. Increased strigolactones trigger a range of adaptations such as shoot growth towards light, root growth to access more nutrients or water, recruitment of soil microbes, upregulation of the defence system, increased senescence and reduced shoot branching. A delicate balance of signalling is required to achieve responses in proportion to what is required. The importance of this balance is demonstrated by strict homeostatic control on the pathway, which includes receptors with built-in ligand destruction and positive-negative feedback with auxin. This presentation will cover some of the experimental landmarks that have unlocked understanding of this important plant hormone.