Thatch

Thatch | Shade | Shade Tree Decline | Weeds | Soil Compaction | Surface Insects | Grubs

WHAT IS THATCH?

Thatch is a layer of living and dead roots, shoots, and stems which develop between the green growing plant tops and the soil. Grass clippings are NOT part of the thatch. If you examine a plug of grass and soil it is evident as a distinct layer on top of the soil.

WHAT CAUSES THATCH?

Thatch develops as a result of the normal growth and die-back of the grass root system. Some varieties of grass produce more thatch than others and it seems to build-up more on heavy clay soils. High nitrogen levels over-stimulate growth so that thatch develops faster. Build-up also occurs with excessive watering which floods soil air spaces and reduces the activity of micro-organisms that break down thatch. Lawns grown on soils which have a pH above 7.2 or below 6 also develop more thatch.

WHY SHOULD I BE CONCERNED ABOUT THATCH?

A small amount of thatch (less than 1/2 inch) will improve the cushioning effect of the grass and help prevent soil compaction. More than 1/2 inch causes a variety of problems. Some of these are..

• more insect problems due to desirable habitat in the thatch.
  
• more diseases which incubate in the thatch layer.
  
• more heat, drought, and cold stress because the crowns and root systems are above the soil and more exposed to the elements.
  
• dry spots develop when the thatch layer dries out because it becomes resistant to rewetting (like peat moss).
  
• thatch tends to trap insect and disease control materials so they cannot reach the soil where they will be most effective.
  
• the lawn is more likely to be cut too short because the mower wheels sink into the thatch.

WHAT CAN BE DONE TO CONTROL THATCH?

The most effective way to keep thatch under control is with core-aeration. This is a process which pulls many finger-sized plugs of soil from the lawn allowing air to penetrate into the root zone. The additional air activates soil micro-organisms which break down thatch. Additional benefits are better water and fertizler movement into the root zone; reduced compaction; deeper root growth and thickening of the lawn.

We get a lot of calls about using a de-thatching machine on the lawn. We do not recommend this practice as it does not reduce thatch. It removes decomposing grass clippings and damages actively growing roots. It is not an effective way to remove thatch.

CAN LEISURE LAWN CORE-AERATE MY LAWN?

Of course! All you have to do is call our office and we will schedule your lawn. Both spring and fall are ideal times to aerate.