The number one pet in America can also be an enemy to
our lawns. Of course, the problem comes when we take our
dogs for their "walk" by letting them run free around
our yard. When Fido does his or her business, the urine
can be damaged or killed.
When a dog, especially a female, releases its urine on
the lawn, the classic symptom will be a somewhat
circular spot. In the center, the grass with be brown
and quite dead. This is because urine has a high
concentration of soluble salts. When these salts come
into contact with plant material, they will quickly draw
the water out of the plant tissue. If they pull enough
water out, the cells will die.
Oddly enough, on the outer edge of the brown spot, the
grass will actually be darker green and taller than the
grass around it. Urine also contains a high level of
nitrogen and as it dissipates moving away from the
center, it actually acts as a fertilizer.
Of course, larger dogs tend to have a larger effect so
try to keep them off the lawn as much as possible. Most
times, you will need to scratch up the brown spots and
work some seed into them. Usually, a few rain storms or
irrigation will dilute the urine's effect so that the
seed will germinate and new grass will grow.