Spring Lawn Preparation – Dethatching Your Lawn

thatch grass dethatch

Spring Has Sprung!

Waking your lawn up the right way


Winter has subsided and spring is upon us!  It is at this time that our quest for the “perfect” lawn begins.  The first step in determine the post winter condition of your turf is to check your Thatch level. Thatch is a layer of dead and living grass shoots, stems and roots that shows up between the soil and the grass blades in your lawn. Thatch build-up starts when the turf produces organic debris faster than it can be broken down. Thatch can be both beneficial and harmful to your lawn depending on the thickness. A layer roughly  half of an inch or less provides the following:

  • Mulching soil and slowing water loss
  • Cushioning soil and decreasing compaction
  • Insulating grass crowns from soil temperature swings
  • Improving turf tolerance to foot and mower traffic

Conversely a thatch layer thicker than ¾” can cause the following:

  • Forming an impervious layer that prevents water, fertilizer, and insect or disease controls from reaching soil
  • Blocking sunlight from reaching lower grass blades
  • Holding moisture against grass blades, which can foster disease
  • Blocking soil so that grass roots grow into nutrient-lacking thatch, which forms a shallow-rooted lawn
  • Creating an uneven lawn, which leads to uneven mowing and scalping
  • Pull up a small cross section of lawn, if the thatch level is equal to or greater than ¾” its time to Dethatch!


Proper Lawn Dethatching


Improper Use of Equipment

dethatching correct vs incorrect pic

Dethatching Checklist:

  • Don’t fertilize the lawn prior to dethatching.
  • If you are planning to apply preemergence herbicides, do so after dethatching. Otherwise, the herbicides may bind with the thatch and decrease their effectiveness.
  • For best results, it is better to dethatch after a light rain or absent that, you’ve watered the lawn. Avoid dethatching when the soil is saturated after heavy rainfall. The reason for this is that the dethatching equipment will pull the soil and tear at the roots instead of slicing and lifting the thatch.
  • Mow the lawn to the lowest recommended height for your particular grass. Bag the clippings.
  • Avoid machines with flexible rake-type tines and dethatchers that attach to your rotary mower blade. These cause more damage than benefits.
  • When using a mechanical dethatcher, it is better to set it too high than it is to set it too low. Since you almost always have to go back over spots several time the blades can be lowered once you become accustomed to working with the machine.
  • Make the 2nd pass at right angles to the first pass.
  • The amount of debris generated will vary based upon thickness of thath layer
  • Remove this debris.
  • Fertilize the lawn with a regular fertilize (non-weed & feed).
  • Water the lawn. This helps prevent excessive drying and helps the grass recover faster.

Call today to reserve your dethatcher at:

Shaughnessy Rentals

Plymouth: 508-746-7368

Abington: 781-878-4624