In this work, we aim to study the elastic behavior of wood-aggregate concrete. The objective is to determine the relevant microstructural and mechanical parameters of the constituents that influence its elastic properties. To reach this objective, we combined experiments and modeling. Experimental results show that the evolution over time of the elastic properties of wood-aggregate concrete is complex: it depends on storage conditions, content of binder and drying time. To well understand this evolution, we developed a micromechanical model based on the self-consistent scheme. This model captures well the experimental data and provides a predictive tool for the behavior of plant-based concrete.