Lawn thatch is the great mystery
of the lawn. Some lawns have this problem, while others do not.
Some areas of the lawn can have more thatch than others. What is
it? How does it form? Is it harmful? How do you get rid of it?
Do you need to get rid of lawn thatch?
What is Lawn Thatch?
It is a layer of living and
dead plant materials between the growing stem portion and root
portion of the grass plant. Thatch up to ˝ inch in depth is not
a problem for most lawns. Once it accumulates to greater levels,
it must be controlled. Otherwise, grass will send roots into the
thatch layer instead of the soil, which will cause the grass to
dry out and die.
Lawn thatch is not caused by
leaving lawn clippings on the lawn after mowing. Leaving lawn
clippings on the lawn is actually beneficial to lawns because
returning the clippings to the lawn returns nutrients to the
lawn.
De-thatching is best done in
the spring or the fall because de-thatching techniques disrupt
roots to the point where recovery is difficult during the hot
summer.
What Causes Thatch?
As noted earlier, it is not
caused by leaving grass clippings on the lawn. Thatch can be
caused by a variety of conditions. Thatch can form on highly
compacted soil, and in cool, wet environments. Thatch can be
caused by grass that is allowed to grow too high, as the lower
parts of the plants will die. Over-fertilized lawns build up
thick thatch layers. A high soil pH can also cause excessive
thatch buildup.
How to Eliminate Thatch
When thatch levels are over ˝
inch, it is time to take action. During the summer, the best way
to remove thatch is to aerate and top-dress. Your lawn care
professional can do this for you. Aerating will reduce
compaction problems. Top-dressing with soil will add organic
matter back into the lawn and help with root growth and moisture
retention. In the fall, thatch rakes and vertical thatch cutters
can be used.
Why Remove Thatch?
Removing thatch is important to
keep a healthy lawn. Thatch is detrimental for a number of
reasons, if allowed to build up. As earlier stated, thick thatch
layers can cause roots to grow into the thatch layer instead of
the soil. Thatch does not hold moisture, so eventually the lawn
will die. Thatch provides an idea place for pests and diseases
to grow and thrive, another good reason to remove it. Lastly,
thatch buildup makes lawn maintenance more costly because you
have to use more water and fertilizer to achieve desired
results.
