Controlling thatch is one of the most important and most overlooked parts of lawn care.
What is thatch?
-Thatch is the layer of living and dead organic matter that accumulates between the soil surface and the green grass above. Thatch build up begins when turf produces organic debris faster than it can be broken down.
-Dethatching removes those layers of dead grass, roots and debris matted between the soil and the growing grass, keeping the grass greener and healthier while minimizing the chance of disease.
Is thatch bad?
-Some thatch is good to have, it insulates against temperature extremes and variations in soil moisture. Thatch also provides a resilient and soft surface to walk on. A good thatch layer is less than a half-inch.
-A thatch layer more than half an inch thick is considered excessive. It makes the lawn feel spongy. Not only can it feel like a sponge, it can also act like a sponge withholding water, air and nutrients that your lawn needs. Too much thatch creates a perfect environment for increased insect presence and moisture-loving fungi. Mower scalping is another big problem in lawns with thick thatch layers, mower wheels sink into thatch and lower the height of the cut.
What causes thatch?
-Thatch is naturally degraded by the micro-organisms in the soil. When soil conditions don't support high populations of thatch-decomposing organisms, thatch buildup occurs. Soil type, soil pH, over feeding, over watering, and pesticides all have an influence on these organisms.
-Over fertilizing causes grass to produce more rapidly than it can be decomposed.
-Over watering reduces the number of thatch-decomposing organisms.
-Soils with a high sand content, by nature have a very low micro organism population
-Overgrown grass, infrequent mowing, and lack of aeration are other main contributors to unhealthy thatch.
-Despite popular belief, grass clippings left behind after regular mowing are not the cause of thatch buildup. Clippings are very high in water and breakdown rapidly after mowing.