Q: Should centipede and St. Augustine lawns ever be overseeded in fall with rye?
A: No to both. Although bermudagrass tolerates ryegrass overseeding reasonably well, centipedegrass and St. Augustinegrass lawns do not. The fertilizer you give the ryegrass will stimulate the centipede and St. Augustine turf and make it susceptible to freezing. Ryegrass growing on top of tender lawns holds winter moisture and causes disease. Rye also competes with the grass when it is trying to green-up in spring.