Lawn scarifying and dethatching to remove thatch & moss
What is lawn scarifying
Lawn scarification plays an important role in any lawn care program.
Scarification, sometimes known as dethatching is the process of removing organic matter (thatch)
from lawns & turf.
Over a period of time thatch will build up in a lawn. This build up is caused by grass clipping,
leaves, in fact any dead or decaying organic matter will add to the thatch layer.
A small amount of thatch in a lawn is considered desirable as it helps encourage a resilient
sward. However when the thatch becomes too deep it creates problems and has a detrimental effect on
the health of the lawn. Ideally lawns should be scarified on a regular basis to prevent the build
up of thatch and prevent it becoming a serious problem sometime in the future.
When thatch becomes a problem it needs removing by intense scarification. For more information
on this lawn problem please visit our thatch page. Thatch is removed by a powered machine with a
series of vertically mounted spinning blades. These blades penetrate into the lawn and physically
rake out the thatch. This machine is called a lawn scarifier or lawn
There are many machines and implements available for this operation, from hand rakes to powered
lawn rakes and scarifiers. A spring bok rake can be used for small areas where build up is not too
severe. If large amounts of thatch needs removing a powered scarifier will be
When to scarify or dethatch a lawn
Lawn scarification or dethatching can be undertaken any time during the growing season when
grass growth is strong, avoiding periods of drought. Strong grass growth is important following
scarification as this aids recovery as this operation can be very severe and the lawn needs
sufficient time to recover.
Traditionally late spring (too remove moss after moss control has taken place) and late summer have been the two
most popular time for heavy scarification. This is because it ties in well with the timing of
spring and autumn lawn maintenance programs.
Lighter operations can be carried out frequently during the growing season to help prevent
thatch build up. This will also help discourage any broad leaf weeds and help
prevent lateral grass growth which in turn will give the lawn a nice clean
How to scarify a lawn
Before you undertake this operation it is important to ensure the soil conditions are suitable
for scarification. Ideally the soil should be moist, not too wet and not too
Mow the lawn before you scarify as this will help with the task of cleaning up the debris that
will be removed by the scarifier. Pick a nice dry day as this will also help with the clean up
work, scarifying during wet weather is very messy as well as hard work.
Once you a satisfied that the conditions are right you can go ahead and scarify. Aim to do this
operation twice, the second pass should be done at a 30 degree angle from the
Once this task is completed you can then go ahead and remove the debris, either with a trailed
sweeper or similar, or by hand using a suitable rake.
Seeking professional advice on lawn scarifying
If you are new to this task it would be advisable to first seek professional advice before
scarifying as using a scarifier incorrectly can result in severe damage to your
lawn. This is especially true if your lawn has never received this treatment previously. So if you
are unsure about this seek the advice of a lawn care specialist.