By Cat Holmes
University of Georgia
Spring has sprung and summer’s hot on its heels, but before you
head out to walk barefoot in the grass, take some time to check
it out for problems.
“Turf grass diseases are hard to diagnose but relatively simple
to treat,” said Alfredo Martinez, a plant pathologist with the
University of Georgia College of Agricultural and Environmental
Sciences.
“Now that grass is greening up, people should go take a walk
and look carefully over their lawns,” Martinez said. “Plant
diseases are just like human diseases. Prevention is essential,
and the earlier you treat them, the better.”
Diagnosing turf problems
When scouting the lawn, what should you be looking for?
“Turf grass diseases usually show up as discolored spots, bare
patches and thin grass,” Martinez said. “At this time of the
year, there are two main turf diseases in Georgia: brown patch
and dollar spot.”
The symptoms of brown patch are circles or patches of thin,
yellowing grass, Martinez said. The circles may range from
several inches to several feet across.
“The causal agent of brown patch, a fungus called rhizoctonia,
grows outwards,” Martinez said. “The resulting patch looks like
a ‘doughnut’ of brown or yellow discolored grass with green in
the middle. The green appears because as the fungus spreads
outwards, weeds or new grass starts to grow in the middle,
creating a doughnut effect.”
Small white patches, only a few inches in diameter, are
probably dollar spot, Martinez said. Sometimes the spots are
close together and may appear to look like larger patches. But
if on close inspection, it’s an aggregate of small, whitish,
circular patches, it’s dollar spot.
Treating turf problems
The best resource for diagnosing and treating turf disease is a
county extension agent, Martinez said.
“A county agent can play a major role in helping prevent,
diagnose and treat turf grass problems,” Martinez said. “It’s
hard for someone who isn’t trained to diagnose turf grass
diseases. The county agent may recommend fertilization
treatment, adding more light or air movement or fungicides. And
if they’re uncertain about the problem, they will contact
us.”
Preventing turf problems
An ounce of prevention is worth a pound of cure when it comes
to turf, Martinez said. One of the easiest ways to prevent turf
disease, he said, is to avoid overwatering.
“Improper watering habits account for a large number of the
cases of turf grass disease,” Martinez said. “People tend to
water for short intervals several times a week. Plant diseases
love high humidity on foliage, and too-frequent watering
actually encourages diseases.”
It’s much better to water long enough for the moisture to soak
2 to 3 inches into the soil, he said.
Martinez says watering regimes should be based on the type of
soil. For example, one good watering each week may be enough
for sandy soils, while clay-based soils hold more moisture, and
water intervals can be extended.
It’s also important to water grass before noon, Martinez said,
so the turf has time to dry out thoroughly before nightfall.
Proper fertilization procedures and rates are also essential to
avoid turf diseases. “Each grass species has particular
fertility requirements,” he said.
Another key is to plant grass that’s appropriate for the region
and your yard. Again, Martinez recommends consulting with a
county extension agent.
“Different grasses do much better in different areas,” he
said. “A county agent can assess an area and recommend turf
suited to that particular location and use.”
If you’re planting grass this spring, Martinez said, prepare
the soil properly. It’s important to remove all rocks, stumps
and debris. Take soil samples to your country extension agent
to get a good idea of what, if any, amendments your soil might
need.
Proper grading is another key. Low areas are bad news for turf,
because that’s where water collects, and excessive water
promotes disease.
