Cytokinins are plant hormones that drive cell division, occurring naturally inside plants and also applied artificially to improve the quality of fruits and vegetables after harvest. They stimulate growth and slow the yellowing of leafy greens, making them valuable to postharvest scientists seeking longer shelf life. Synthetic versions support plant tissue culture and uniform crop development. Although invisible to the consumer, these regulators quietly shape the appearance and keeping quality of much of the produce on display. Research continues into formulations that hold treated produce looking fresh without affecting safety or flavour.