Plant ecological epigenetics aims at understanding how epigenetic changes affect the ability of plants to adapt to the environment. This is important for predicting species responses to global change. The Lombardy poplar (Populus nigra cv. ‘Italica’) is a unique system to study epigenetics in trees. It is a male clone that has been widely planted throughout Europe since the 17th century. As such the identical genotype covers a wide range of environments and allows to investigate the ecological priming inferred by these environmental conditions. In this project, P. nigra ‘Italica’ clones from twelve sites across European-scale geographic and climatological gradients will be investigated. Specifically, DNA methylation will be screened in order to characterize epigenetic structure, associate methylation variants with relevant ecological and climatic variables, and assess the contribution of environmental induction to epigenetic changes relative to stably inherited methylation patterns. Additionally, cuttings from the twelve sampling sites were planted in a common garden with a random block design to screen phenotypic differences. In autumn 2018 and spring 2019, growth and phenology parameters were scored in 375 trees. The date of winter bud set did not differ between sites and no correlation with climatic variables was found, but the day of bud set showed a positive correlation with height and diameter.