Ethylene-based polymer blends having an MWD of at least about 2 are made in a single reactor using a mixed constrained geometry catalyst (CGC) system. The process comprises the steps of contacting under polymerization conditions and in a single reaction vessel (i) ethylene, (ii) at least one C.sub.3 -C.sub.20 .alpha.-olefin, (iii) optionally, at least one polyene, and (iv) a mixed CGC system.