All About Thatch and Lawn Aeration

From: Olson Lawn Care, Broomfield, Colorado

1. What is thatch? 

                Thatch is a layer of organic matter made-up of dead grass blades, old grass roots (rhizomes), and other debris that forms a layer between your grass plants and the soil.

2) How is thatch formed?

                Thatch is a naturally-occurring process.  It can be worsened, however, by other factors —   Some of the more common causes being the following:

a) Colorado’s heavy clay soil prevents air and water from aiding the process of natural decomposition in the soil.

b) Heavy foot traffic will contribute to the compaction of thatch.

c) A thick layer of clippings doesn’t break down properly.

d) Shallow watering causes roots to concentrate at the soil surface.

3) Is thatch bad for my grass?

                Yes and no.  Again, thatch occurs naturally.  Generally, you should not have a thatch layer more than half-an-inch thick.  A thatch layer exceeding that amount, however, and it becomes an impenetrable layer that does not allow water or nutrients to reach the grass roots.   Thatch can make your grass bumpy and difficult to mow.  Excessive thatch also contributes to insects and disease.

4) How do I know if I have a thatch problem?

                There are several ways of determining if you have a thatch problem:

a) The grass will seem “spongy” when you walk across it. 

b) After only a few minutes of watering, the water will run-off the lawn.

c) Brown, worn areas where people frequently walk.

d) Water puddles after using a sprinkler.

             You can always take a shovel or a hand-digger and remove a small wedge of grass to see how thick the thatch layer is…

5) How do I treat thatch?

            Unlike a garden, the soil beneath your grass is never tilled (or turned).  There are essentially two options:  De-thatching and aeration.  The former uses a machine to literally power-rake your grass, and is only recommended for yards with severe thatch problems.  Unfortunately, this can often tear-up your lawn.  The second option, aerating, is recommended.  For small lawns, it can be done manually using a special garden tool and a bit of sweat and muscle.  However, we recommend a machine aeration.

6) What is aerating?

            Aeration is the process of creating small, vertical holes in your yard.  This can be done manually the old-fashioned way using a hand aerator, or more common is to use a core aerator, a machine which pulls tiny, 2-3 inch cigar-shaped plugs out of your grass. Aerating not only breaks-down the thatch layer, but allows water, air, and nutrients to enter the soil.  Aerating also helps tiny micro-organisms that help your lawn.  The plugs will naturally break-down and dissolve back into the soil within a couple of weeks.

7) How often should I have my lawn aerated?

            Given Colorado’s heavy clay soil, at least twice a year – once in the Spring (at the start of the growing season) and again in the Fall (After the grass has gone dormant). 

8) Should aeration be conducted along with other treatments?

            Yes – It is ideal to fertilize and overseed after an aeration. 

How can I get an aeration?

            Olson Outdoors offers aerations for $40 (for a typical-sized yard).  We are one of the leading lawn and landscaping companies in the communities of Broomfield, Westminster, Thornton, Arvada, Erie, & Superior, Colorado! Call us at 720.201.7561 to schedule an appointment or email us at olsonlawnservicesllc@gmail.com