I purchased a home 3 years ago with a small rye grass lawn that is increasingly being covered by a growing river birch tree. As a result, for roughly 2/3's of the day, the majority of the lawn is in the shade. The yard is also regularly used by neighborhood children for soccer. Regular attempts to overseed and core aerate in the spring and fall seem to help but the rye grass has persistently getting thinner and patchier except for the corner that continues to received full sunlight (even though it's dead center of the soccer "field"). Reading that your department generally recommends tall fescue, and given that it seems to have both high foot traffic and shade tolerance, I started overseeding tall fescue into the lawn this spring and I'm planning on continuing doing this twice a year for a few years. That said, I've also read that rye grass is allelopathic and that overseeding tall fescue into it could make the lawn vulnerable to disease. Do you have any thoughts on how to reconcile these pieces of advice? Is overseeding tall fescue into thinning perennial rye a reasonable solution?