Natural fibres contain structural distortions known as dislocations. Dislocations have been found to negatively affect the properties of plant fibre-based materials. The present study concerned the effect of the growth conditions of hemp plants (Cannabis sativa L.) on the amount of dislocations within the fibres retrieved from the stems. Dislocations were found in fibres from plants grown under absolutely wind-free conditions, but both windy and dry conditions introduced significantly more dislocations. Furthermore their maximum size was larger and they were situated closer together within the fibres. The average ultimate tensile stress of fibre bundles from the windy and the dry growth regimes was lower than that of fibre bundles from plants grown under wind-free conditions. In a separate study it was found that plant stems that were dried after harvest and remoistened prior to analysis contained a lower amount of dislocations than plants analysed directly after harvest.