Every lawn, whether new or established, is susceptible to a variety of lawn
diseases. Most lawn disease starts with a fungus. Fungi are an oddity because
they don’t set seeds; instead, they propagate by distributing spores in their
surrounding area. Some of the spores are picked up by wind or animals and
distributed in new locations.
Diagnoses of Lawn Disease
One of the biggest problems in controlling lawn diseases is diagnosis. By the
time signs of infection are evident, the fungus that causes it is often
difficult to control. Although there are dozens of types of lawn disease, most
can be prevented through regular lawn care. Most fungus spores lie dormant until
conditions are right for them to grow and infect your lawn. Generally, fungus
spores need warm temperatures, a moist environment, a source of nutrition and a
susceptible host. Although you can’t control the weather, you can deprive them
of the nutrients they need as well as a susceptible host.
How to Water
Water your lawn deeply and infrequently to deprive fungus of the damp
environment it needs. In addition to helping the prevention of lawn disease,
deep and infrequent watering encourages your turf to sink deeper roots. Water
only when the surface soil is dry to your touch and then water to a depth of two
to three inches. You can gauge how much water your lawn is getting by “planting”
a small container (such as a tuna or cat food can) in a corner of your yard. In
addition, schedule irrigation in the morning to give excess water a chance to
Heavy thatch layers (over ½ inch) hold both heat and moisture and provide fungus
with a ready supply of nutrients. Thatch also impedes drainage and blocks the
airflow your lawn needs to thrive. Annual core aeration in the spring is the
best way to control thatch buildup. You can also control thatch during the
growing season by maintaining your lawn at a 2 ½ to 3 inch height and cutting no
more than ⅓ of the height when you mow.
Mowing time is also a good time to check your lawn for signs of disease. “Fairy
rings”, “frog-eyes”, brown patches and other irregularities may signify the
beginning of a problem. However, before you purchase a “remedy” it’s best to
have an infected patch inspected. Dig and take samples to your extension agency
or to a recognized lawn care professional.
Many strains of fungus quickly develop a resistance to the best fungicides.
Controlling active fungus is truly a case where “an ounce of prevention is worth
a pound of cure”. Start your lawn disease prevention plan by planting only
disease resistant grass hybrids whether beginning a new lawn or reseeding
patches of an old one.