The natural growth rate of grass slows down when a thatch of leaves, old grass clippings, dead roots and moss has built up. It can lead to reduced resistance against diseases and therefore increased vulnerability and growth problems.The Trilo VCU Verticutters are specially designed for sports fields, flat areas and parks, racetracks and gold course fairways and can easily handle thatch build-ups all the way down to 1.5″ without any problem.