Most tall fescue grows in clumps — when a patch dies, it stays dead until you reseed. North Star is a rhizomatous tall fescue (RTF): it sends out underground stems called rhizomes that push new shoots sideways, so the lawn knits together on its own and fills in bare spots, dog paths, and thin areas without a second seeding. You get tall fescue's deep roots, heat and drought tolerance, and shade performance, plus the self-healing you'd normally only get from bluegrass.