I always had the belief that a lawn should be de-thatched every 3-4 years to help it stay healthy. Some recent conversations with folks who know more about this than me tend to disagree; they say don't de-thatch until you have a 3/4" buildup of thatch extending into the soil. What do you guys think? Will premature de-thatching hurt the lawn or is it just a waste of time? Are you better off not to thatch?