Apparatus for making a low density fibrous mat for use as a self-contained support system to enhance the growth and probability of survival of an established seedling or a viable seed which has at least two adjoining layers of lignocellulose fibers bonded together by an adhesive of the type weakened by exposure to an outdoor environment. The apparatus is characterized by a pneumatic fiber conveying and depositing means in which the pneumatic conveyor is charged by rotatable tined shafts above a screw-conveyor and a following belt conveyor from which the fibers are drawn into the pneumatic conveying system for eventual deposition on a continuous vacuum screen.