According to the present invention a composite structure is provided comprising in intimate mixture essentially through the whole composite structure: peat fibers, peat particles, peat agglomerates or mixtures thereof, that have been obtained from horticultural peat by fractionation or by producing from peat fines； and polymer fibers, which composite structure has been heat- treated to bind the polymer fibers to each other and to stabilize the peat fibers, peat particles, peat agglomerates or mixtures thereof in place in the composite structure. In addition, a process is provided for the production of the composite structure.
