Interactive installation with 21 luminous trees in Amsterdam South-East, as a prospect of a future in which natural luminous organisms provide orientation light. A bio-based coating on the stem is briefly exposed to LED lamps with a spectrum near UV. As a result, the trees provide a subtle glow, a concept particularly suitable for dark environments. The installation is interactive. Using UV flashlights people can tag the logs temporarily, the drawing slowly fades away. The installation is an initiative of SIGN and a continuation of our experiments with light-emitting plants.