Turf Tips:
Thatch? Aerate?
by Nellie Neal
Here’s
how to tell if it’s time to do these major lawn renovations to remove
choking thatch or add oxygen to the root zone. Both are best done in spring
so the lawn can recover over the long growing season.
Too much
thatch makes for wasted lawncare. The water and fertilizer you carefully
apply and even sunlight cannot penetrate a thick mat of slowly decomposing
grass clippings. Thatch builds up over a period of years and fine bladed
grasses seem to suffer most – the lawn looks pale, may have yellowed lower
leaves and can get thin in spots. When you walk across a dry lawn and it
feels mushy beneath your shoes, get down and inspect the dead grass you
loosen up between the green blades and the ground. You may be surprised how
much thatch has accumulated.
Annual
raking with a tool made specially for the purpose can do a lot to prevent
the buildup, dethatching blades are available for many mowers and
dethatching machines can be rented for big jobs demanding complete
renovation. Be aware that removing thatch mechanically often makes for a
nearly bare lawn – keep kids and pets off of it for at least a month to
let the grass begin to regrow. Mow at the highest setting appropriate for
your grass type and fertilize after the first cutting.
If
compacted soil presses down tightly in the rootzone below your lawn, the
roots are deprived of vital oxygen and the lawn cannot grow. Kids playing
ball, pets running in circles and the natural path that cuts the distance
from driveway to front door – all these areas get trampled regularly and
may need aeration to repair. When you look across a well-watered lawn and
see flat-looking areas, examine them for signs of compaction: thin turf and
hard soil.
The
object of aeration is to open up the rootzone by removing cores of compacted
soil. The half inch holes you’ll punch across the area will shortly refill
with shifting soil loosening the entire area. Some gardeners walk across the
areas wearing devices that look like dangerously spiked golf shoes. For
bigger areas and denser compaction, use a step-on aerator. This metal device
has a T shaped handle on a single shaft over a plate with hollow core
removers underneath. You hold the T in both hands and step on the plate to
push the tool into the ground. When you pull the tool out, the hollow pipes
are full of soil cores ready to drop into the compost pile. For large
compacted areas, rent a mechanical aerator.
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