Abstract Vegetated areas or agricultural environments are potentially important sources for particles initiating the formation of ice crystals in clouds. In this work, we present results from lab-based studies investigating the ice nucleation properties of particles from leaf litter and agricultural soils at mixed-phase cloud conditions, i.e. at temperatures above 250 K. We also investigate the ice formation properties of individual organic components, e.g. plant-based lipids, which presumably contribute to the observed ice nucleation efficiencies. In most cases, however, we find that ambient particles tend to be significantly more ice-active than individual organic components.