Abstract

Four polypropylene fabrics and five polyethylene (plastic) films, covered with shredded pinebark mulch, were compared for suppression of large crabgrass (Digitaria sanguinalis (L.) Scop.) and bermudagrass (Cynodon dactylon (L.) Pers.) shoot and root growth, and root penetration. No covering completely controlled either grass, but significant differences existed between materials, with Weed-X giving the best overall shoot suppression. Penetration of both grasses' roots was less through Weed-X, Weed Control and brown polyethylene than through Weed Barrier, Duon, Typar, WeedBlock, Magic Mat and Weedstop. Weed growth in the mulch layers atop the fabrics and films are significant. Resistance to weed root penetration was possibly related to the percent of open versus closed areas of the fabrics and films. Fabrics or perforated films with greater root penetration resistance should generally provide greater overall landscape weed control than those allowing greater root penetration.