One of the many steps towards reaching the UK’s goal of tripling its tree planting figures to 30,000 hectares a year is increasing the current tree production output. Threats such as ash dieback disease shed light on the need to maintain certain genetic features, calls for the development of complementary clonal propagation protocols. Stem cuttings are simple propagules that, upon successful development of adventitious roots, may provide high numbers of individuals with the desired features for the future woodlands. Cuttings from broadleaved tree species such as oak and ash are often considered recalcitrant to rooting, especially as they age. Auxin-containing powders and solutions are the main rooting enhancer treatment used in nurseries, though often unsuccessfully in hard-to-root cuttings. With the role of auxin being knowingly dependent on time, a single application might not provide the target tissues with adequate auxin levels. In this project, we are monitoring the responses to different auxin formulations along time and correlating it to rooting-related physiological parameters. Early results evidence the low rooting rates of oak and ash cuttings, higher callus formation rates in warmer seasons, and a strong seasonality factor, with the few rooting events taking place in cuttings collected in late summer-early autumn. Observation from the next, larger experiments will be used to build a working model for how different physiological parameters affect rooting outcomes in UK tree cuttings, paving the way for improved, data-driven propagation protocols.