Blends of very low density polyethylene produced using metallocene catalysts (mVLDPE) and polypropylene are disclosed. The polymer blends include a metallocene-catalyzed VLDPE polymer having a density of less than 0.916 g/cm3, the mVLDPE polymer preferably being linear and without long chain branching, a polypropylene homopolymer, random copolymer, or impact copolymer, and optionally flame retardant additives. The polymer blends are particularly suitable in membrane applications where increased tear resistance and tensile strength are desirable, such as in roof membranes, geomembranes, and pond liners.