Abstract: A separator is provided for use with a ditching machine to segregate rocks and coarse aggregates from the material excavated by the ditching machine s that the excavated material may be used as padding to protect the pipeline or other item positioned within the excavated trench. The separator comprises a plurality of rows of blades mounted on a rotatable drum. The spacing between adjacent blades within a row allows passage of the fine excavated material between the blades but prevents passage of the rocks and coarse aggregates. The rotating blades then deposit the rocks and coarse aggregates in a row beyond the row of fine material deposited along the trench.