Growing trees respond to mechanical disturbances, e.g. resulting from environmental forces or gravity, by forming so-called reaction wood, i.e. compression wood in gym- nosperms and tension wood in angiosperms. It enables the tree to control its posture by reinforcing and reorienting the axes of stems and branches [1] – a key prerequisite for reaching large heights. The movement is due to asymmetric cambial activity resulting in excentric growth and varying growth strains. While the underlying biological mechanisms of growth strain generation are not yet fully understood, various hypotheses correlating the induced macroscopic movement with the difference in cell wall structure of reaction and non-reaction wood have been proposed [2]. On that basis, a homogenization procedure was employed for upscaling of elastic proper- ties and evaluating the macroscopic effect of growth strains implemented at the cell wall level. To do so, Herv ́e-Zaoui’s n-layered cylindrical inclusion problem [3] was extended for anisotropic constituents and utilized for modeling of the cell wall. Applying geometrically non-linear beam mechanics to a growing branch inclined with respect to the vector of gravity allows to simulate the reorientation process induced by growth strains at the cell wall level, introduced via the aforementioned micromechanics model. In combination with experimental data of the branch shape evolution found in literature of specific species, growth-related parameters can be deduced, giving access to new insights into the dynamics of wood growth.