Seasonal effect on the chemical composition of the leaves of Stipa tenacissima L. and implications for pulp properties

► The chemical properties of esparto leaves varied with the growing conditions. ► In fall, esparto leaves contain more cellulose compared to other seasons. ► In winter, esparto leaves have lower cellulose content and higher extractive content. ► Pulp yield and strength properties of esparto fibers are superior when leaves are harvested in fall. ► The results of this study could be used to develop a suitable harvesting program that respects the esparto plant biology.