University of Vermont Extension
Department of Plant and Soil Science
Fall News
Article
FALL LAWN CARE
Dr. Leonard Perry, Extension
Professor
University of Vermont
Proper lawn care in fall, including
mowing, fertilizer, and watering, will help it survive winter in
good
health. It will be able to resist
diseases and weeds better next season, and start off next year in
good shape.
As long as the grass is growing, keep
mowing, and mow at the proper height.
This is often the most misunderstood and abused part of lawn care.
Most grasses should be mowed at 2 to 2-1/2
inches high in spring and fall, and 3 inches high in the heat of
summer. The last mowing of the season can be on the
short side, about 2 inches high. This
will help prevent the grass packing as much under snow, making it
susceptible
to leaf diseases such as snow mold.
Another aspect of mowing height is
not to cut off more than one third at any mowing. So if the grass
gets too tall, decrease the
height to the ideal in a couple of mowings, the first being higher.
This way you won't have an excess of long
grass clippings that may cause thatch, and can leave them on the
lawn-- a good
practice as these recycle nutrients and organic matter back into the
soil.
Higher mowing is important to grass
for at least two main reasons. More leaf
area on grass plants means they'll be able to make more
carbohydrates needed
for healthy growth. There is a direct
relationship too between the amount of tops and roots. The more
tops to the grass plant means more
and deeper roots, which in turn means the grass can better withstand
stresses.
It is important to send the grass
into the winter as healthy as possible, which means adding
fertilizer
in early fall is important; in fact, this is perhaps the most
important
fertilizer to add all year. Add about one pound of actual nitrogen per
1000 square feet of lawn. So if a fertilizer
is 10 percent nitrogen, you would add 10 pounds of this product over
each 1000
square feet (5 pounds of a 20 percent fertilizer). You'll want a
quick release fertilizer so the
grass can take it up before winter. Most
of slow release fertilizers will be lost in the soil (or worse into
watersheds)
over winter when the grass isn't growing.
If you haven't tested your soil
before, or in a few years, now is a good time.
The results will tell you if any other fertility or lime is needed.
As many soils become more acidic over time,
lime is often needed to keep the soil acidity or pH between 6.0 and
7.0. Add lime in the fall as it is slow acting,
and its effect won't be fully realized until spring. Soil test kits
are available from many
full-service garden stores and your local university Extension
offices.
In addition to proper mowing and
fertility, watering is key to helping your lawn go into winter
healthy and without
stress. If rain is infrequent or too
light, make sure the lawn receives at least an inch of water a
week. This is where an inexpensive rain gauge from a
garden or hardware store comes in handy.
Or you can get a more elaborate wireless rain gauge from complete
garden
suppliers. Often during a rainy spell
you may think you're getting more rain than really is falling.
If you've been using the lawn during
the growing season, with lots of foot traffic, play, or even driving
on it, the
soil is likely compacted and could benefit from aeration. This
simply involves penetrating the surface
with holes so air, water, and nutrients can reach the roots. One
simple method is to use "aeration
spikes" you can buy in garden stores and catalogs that slip onto the
bottom of your shoes. As you walk on a
lawn these break through the compacted surface.
Or you can rent a special aerator machine from rental firms, or hire
a
professional lawn care firm.
Once aerated, or if the soil is fine
without this, overseed if your lawn is weak and needs a bit
more grass. Buy a good grass seed blend
of varieties, scatter it as needed over a sparse lawn or bare spots,
and water
in. Grass seeds get established more quickly
during the cool fall than hot summer, and when pressure from weed
competition
is low.
Another misunderstood part of lawns
relates to thatch-- a mat of living and dead stems and roots on the
surface
that slows water, nutrients, and air from entering the root zone.
This is not caused by short grass clippings,
but often by improper culture or environmental conditions. If this
thatch layer is more than an inch
thick, consider renting a dethatcher machine, or hiring a lawn care
professional
to help with this.
If you have broadleaf weeds, spot
treat or dig out. There are special
tools just for the deep roots of dandelions.
I have a friend who plants a sprig of thyme in each hole made where
a
dandelion root was dug. This will create
a nice aroma over time as you walk through the lawn. There is no
need to use a general herbicide
product now, as many work on grass seeds which aren't growing, and
it may kill
lawn grass seeds you put down.
Once you reach the end of grass
growing and mowing season, early October in colder areas and latter
in warmer
ones, make sure you keep leaves raked up as they fall. Otherwise
these will smother the grass. Use your leaves for compost, or for
mulching
beds. Many like to run over them first
with a mower to shred them, or put them through a shredder you can
buy just for
garden clippings and leaves. I pile mine
on a future garden area, covered with some poultry wire or netting
to keep them
from blowing away. As they break down
they'll make great organic soil.
Return to
Perry's Perennial
Pages, Articles 