If it ever stops raining:Learn when to water
March 24, 2005
GAIL E.
It's the oldest saying in the world: "The grass is greener on the other
side." Is this true in your neighborhood? There are so many
characteristics that could cause a neighbor's turf to be greener than yours.
And by the way, greener may not be better! A really dark green turfgrass may be one heading for failure. If it is a dark
green, there are too many nutrients applied, which predisposes the turfgrass to a high level of disease. While that is a whole
other topic for another article, my goal today is to tell how to water your
turf so it can receive your approval of a green, healthy lawn.
You might ask, "Why talk about watering grass now when we have received
so much rain?" Well, remember it WILL get dry in a short few months and
there are other reasons, too, that I will mention shortly. First, let us stand
back and observe our lawn - and see what it is telling us. If signs of folded
leaves, footprints that don't spring back when walking across the grass,
wilting grass or an overall change in color of the canopy from green to a
bluish or brown hue exist, your lawn is screaming "drought stress."
On the contrary, your grass can be sitting in water (walking in it will cause a
sloshing sound), and it can also wilt from being waterlogged. If this occurs,
quit watering and look into ways to improve drainage.
Now that sounds simple, even elementary, but it is unbelievable how many
yards have had sprinklers running through the wettest past six months in our
history! Excessive water affects grass just like excessive nutrients affect
grass (since water is a nutrient) and this, too, can lead to failure with
disease problems when the weather warms up. Waterlogged soils kill deep roots
and only shallow roots remain alive, if the grass survives.
While we can't easily change our soil type, an ideal turfgrass
soil has equal parts of air space, soil and water. If there is truly air space
in the soil, then it usually does not get waterlogged. But if you are blessed
with the heavy, black clay soil, your turf may suffer from waterlogging
due to very little air space in clay soils and recent persistent rains. The
best advice is to drain the soil internally by putting in drainage tiles. This
allows for a more ideal soil profile, one that produces root growth throughout
the entire profile instead of just in the top few inches.
So now let's say everything is getting back to normal, things are drier and
grass leaves are starting to curl. When should you water? David Chalmers, Texas
Cooperative Extension turfgrass specialist, says that
the best time to water is in the early morning. The wind is usually calm and
the temperature is low, so less water is lost to evaporation and the grass is
already wet with dew so you are not extending the wetting period. The worst
time to water is in the late evening because the grass stays wet all night and
into the dew-covered morning, making it more susceptible to disease. Also, the
evaporation rates are higher in the evening.
Next we need to consider the duration of watering. There are various methods
to use. If you like to manage your lawn correctly, then you need to apply
enough water so the soil is moistened to a depth of 4-6 inches. Chalmers shared
a method to measure this with our master gardener training class last fall. His
method consists of sporadically placing five cans in your yard (tuna cans work
great). Turn on the irrigation system or sprinklers and water for 30 minutes.
Use a ruler and measure the amount of water in each can and record the
information. Calculate the average depth of water. His example used was: 0.5
+0.4 + 0.6 + 0.4 + 0.6 = 2.5 inches. 2.5 inches divided by 5 (cans) equals 0.5 inches of water in 30 minutes.
Next he said to take a garden spade and push it into the ground opening a
hole 6 inches deep for a cutaway view. You are looking to see the depth the
water soaked into the soil. Once you know this, you can determine if you need
to add time to the 30 minutes or decrease time to achieve the 4-6 inch soaking.
The goal of this is to eliminate runoff and waste of water, yet still provide a
deep watering for a healthy root system.
With many irrigation systems, timers can be set to have a greater efficiency
in watering, especially if there is loss from runoff. Set the timer to have
several cycles for short periods of watering, still totaling the full time
length, to help eliminate runoff. Water 15 minutes, wait one hour, and water
the second 15 minutes. This allows the water to soak in instead of running off.
There is one more approach Chalmers discussed with the class. Again, his
goal was to maintain a healthy, water-efficient canopy of green grass. He
stressed that those who live in
So, if you are not into digging into your lawn to see if it is dry 6 inches
deep, just let the lawn dry out and water only when the conditions are starting
to look dry, but not stressed, as described above. Keep in mind,
you still need to gauge runoff and the length of watering time because you
don't want to over-water. This, too, provides a more efficient use of water and
a healthier lawn.
With this knowledge, you can successfully water your turf when it begins to
show signs of drought stress. You can also help
While turfgrasses and their care will be not
emphasized on the upcoming Annual Garden Tour, each yard does have a kept and
managed lawn in its landscape design with planted beds and containers. Be sure
to mark your calendars for April 30 and May 1. Tickets will be available at
various outlets the first week of April. A new feature this year will be two
educational workshops available each day of the tour. If you are interested in
bonsai or container gardening, consider signing up on a first-come,
first-reserved basis. Look for more AGT information in each upcoming issue of
this column.