Looking for Thatch, Then What?

This year I’ve been to a few yards to look at issues with turf. In some cases, not all, the grass has had a thick layer of thatch under the green blades of grass. Thatch is the old, dead stolons or runners from the growth of previous years. Thatch is created when the grass is growing so fast and producing so much new growth that the old growth doesn’t get broken down fast enough to keep up with the new growth. One major cause of this is fertilizing too much with nitrogen.

Dethatching a lawn causes a lot of damage to the existing grass. As I mentioned earlier, June brings on the heat and that means the grass is growing vigorously, so this is a good month to dethatch the lawn. It's also early enough in the growing season that the lawn will have plenty of time to grow and fill in any gaps created by the dethatching process.

This is not to say that no fertilizer should be used. Lawns need fertilizer to grow vigorously enough to choke out weeds and overcome the feeding of insects. Knowing how much fertilizer is being applied is important, so overapplication doesn’t occur.