Thatch is also the build up of
dead grass on a
lawn. Severe thatch can kill a lawn. Dethatching a lawn can
treat the symptoms, and may be necessary, at least to improve the appearance of your lawn. But to prevent the problem you need to
aerate your lawn on a regular basis.
Core aerifying, both prevents, and cures, thatch. I rather think that dethatching and power raking was "invented" by the
lawn care industry. So instead of buying a
dethatcher or hiring a lawn care company to dethatch your lawn; buy a
core aerator, or even one of those two-hole manual core aerator's. The
pluggers will penetrate any modest layer of thatch to allow
nutrients,
water and
oxygen to reach the
roots.
Note: do not buy a shoe-attached aerator they don't work.