The area under trees has the double whammy of being shady and
Just as "grass doesn't grow on a
playground" it often has a real tough time growing under trees!
A combination of factors makes growing
grass under trees extremely difficult. Lawn grasses not only have to
compete with tree roots for moisture and nutrients, they also have a
tough time getting enough sunlight. Therefore, there are several
steps you can take to encourage lawn growth in the dry shade underneath
The area beneath a
tree can be very dry as well as too shady for a good
lawn. Thin tree branches to allow more sunlight to reach
the lawn. Consider using mulch or ground cover in
extremely shady areas.
How to keep grass under a tree
In order to maintain turfgrass under a
tree, you need to do the following:
Thin-out tree branches to allow
the maximum amount of sunlight to reach the ground. You will
need to repeat the thinning-out procedure every few years. Avoid
"topping" trees if at all possible.
Mow the lawn at the tallest
height possible without the grass laying-over. Longer grass
blades are able to intercept more sunlight. Also, longer shoots
mean deeper roots!
Water lawn areas beneath trees
thoroughly once a week during dry spells. Tree canopies can shed
rainwater away, making the soil beneath trees extremely dry. In
addition to that, tree roots remove moisture from the soil,
creating severe competition with lawn grasses.
Planting grass under a tree
In spite of proper thinning, mowing,
and watering, shady areas under trees often need to be reseeded
every year or two. It's often necessary to add just enough soil to
create a seed bed, since the existing soil can be filled with
fibrous roots. While it can be very detrimental to add soil over
most tree's root zones, limited soil fill over some tree roots
shouldn't cause any major problems.
ADDING SOIL UNDER TREES
The depth and extent of the soil fill should
be limited as much as possible. Some tree species can be killed by
just a couple of inches of soil over their root zones. Consult with a
professional landscaper or arborist before adding soil to a tree's
In the example below, we were contracted to seed an area beneath a
pin oak that had recently been thinned-out by a tree service. Due to
the mature size and species of the tree, it was determined that
adding a thin layer of soil to the root zone wouldn't cause any
BEFORE The area
beneath this Pin Oak was very shady before a tree
service thinned the canopy to permit more sunlight to
reach the lawn surface.
A thin layer of
shredded topsoil was used to smooth the area and create
a seed bed.
The area was then
seeded with a "shade mix" consisting mostly of Fescues.
"Starter" fertilizer was also applied to encourage new and
existing lawn grasses.
AFTER One month
later, the tree's root zone looks like a lawn again.
Proper follow-up care (as outlined above) will be
necessary to keep this lawn looking good.
In most cases, tree
roots will eventually find their way back to the lawn surface, and
this sort of "fix" may only be temporary. If you have an extremely
difficult area that seems impossible to grow grass, consider
mulching the area or planting a shade-loving ground cover. Remember
to check with a professional before adding soil to a tree's root