Longitudinal growth strains are commonly measured at tree periphery by cutting two grooves and recording the released deformation between them. In the case of small stems, it is likely that the whole periphery will be rapidly influenced by the cutting. This paper aims to verify this numerically and experimentally using strain gauge records at 4 positions around the stem. Various configurations of tension wood occurrence were simulated using finite element method, assuming linear growth stress profiles along each radius. An experiment was performed on two stems of a small coppice Chestnut tree (Castanea sativa Mill.). By application of superposition principle the simulations could be adjusted to fit quite well the observed influence of groove depth on the measured released strain.