A common misconception among do-it-yourself lawn care people is that renting a power rake to dethatch
the lawn is the cure-all answer to a healthy lawn. While many times it is necessary, it isn’t
always the only answer, and sometimes may not be necessary at all. Thatch is the accumulation of dead
grass and organic material that occurs from normal lawn growth as old grass dies off. It is not a result
of leaving grass clippings on the lawn. The thatch forms a matted layer that reduces the effectiveness of
pesticides and fertilizers and also forms an ideal breeding area for insects and lawn disease. When the
thatch layer exceeds ½” it is time to dethatch. Thatch removal uses a power rake with a reel of rotating
flail blades that “scratch” the surface of your lawn without penetrating the dirt to loosen up all
of the dead grass (thatch) that has been matted into your lawn over time. It is something that is typically done
in the spring, but care must be exercised to make certain that the good grass has firmly taken root and the soil
is sufficiently firm to prevent removal of the good grass. If your soil is compacted dethatching is best done in
spring but dethatching in September is an advantage because fewer weed seeds germinate in the fall.
However, thatching is only one aspect of lawn care. It does nothing for the soil itself. If the roots are
tightly packed within the soil or the soil is compacted to the point where the nutrients just can’t
get to the roots it needs to be loosened up a bit. Lawn aeration is the process where a lawn aerator moves
over the surface of the lawn and removes a series of ¾” diameter core samples from the soil.
This has two main advantages. The first is that the soil now has room to expand, relieving pressure on the
roots. Instead of compacted soil, it now can relax and become more porous, which allows the roots to breathe and feed
once again. Secondly the new holes form temporary wells which will hold whatever nutrients applied to the lawn. For this
reason it is important to water and fertilize as soon as possible after aerating. The plugs left on the surface break up
and disappear generally in about a week and the core holes close up after time as well but the soil will remain
porous for a long time. If your lawn needs thatching it should be power raked before the lawn is aerated. Lawn
aeration can be performed any time of the year but best results are obtained in either spring or fall. Fall
aeration does enhance the root growth because the fertilizer is better absorbed by the roots due to the lack of
weed seeds, which don’t germinate well in the fall.
now reach roots
Overseeding is the application of seed by cutting slits into the lawn and dropping seed down into these slits.
This is done in one pass by a power slit seeder. A power slit seeder looks similar to a power rake with a hopper
type lawn seeder attached to the front. But, instead of a flail type reel that tickles the surface of the lawn, a
slit seeder has a rigid delta wheel which is designed to penetrate the soil to an approximate ½” depth. As
the slit seeder moves along the seed is dropped at the same time. Overseeding is typically used when an existing lawn
needs to be reseeded and it is not desirable to rip it up and start all over. Quite frequently a new lawn will be seeded
with a fast growing grass that is designed to take root and establish quickly. Later on a more plush lawn is desired.
This is a perfect case for overseeding. The existing grass acts as a mulch to help the new seed germinate as well as
eliminating water erosion that could occur if the soil was bare. It can also be used when an existing lawn was damaged due
to drought or disease. Overseeding is generally the last step and should be done after any dethatching and aeration have been done.
Cut Slits - Drop Seed - and Watch It Grow!
In order to properly care for your lawn a quick analysis is required by the owner. Walk your lawn and inspect it.
Is there excessive thatch buildup? Is your soil firm? Does water run off your soil without adequately penetrating it?
Do you have brown spots that need reseeding? Following these simple steps will help you determine the proper course of
action for your lawn. After that it’s a simple matter to rent the required equipment and wait for the results.
A matted lawn creates a barrier to nutrients and a breeding area for insects and disease.
Aerator cores can be up to 3"long.
Rear of aerator - showing tines
Flail Reel - Dethatcher Tines
Delta Reel - Slit Seeder Tines
Power Slit Seeder