seed – posted 23 January 2001 10:13
Here’s a question I got through e-mail, “what if any are harmful effects of rye grass over seeding to St. Augustine?”
My answer, “I am not aware of any harmful effects of overseeding ryegrass into St. Augustine. However, it is not normally done because St. Augustinegrass has such a thick mat of thatch, that it is difficult to get even germination. Even overseeding of bermudagrass may require vertical mowing or vigorous raking to expose the ground to the sunlight, so the ryegrass seed can be in close contact with the ground, and still have sun.
But St. Augustinegrass has a deeper mat of thatch, and the proper preparation for overseeding involves a damaging amount of dethatching. While I have not personally overseeded St. Augustinegrass, I have seen sporadic, patchy establishment of ryegrass in St. Augustine, which is probably why we in Florida do not normally practice it.