by The Long Island Gardener

Created on: July 16, 2008   Last Updated: October 06, 2011

No doubt about it: Man's Best Friend is Lawn's Worst Enemy. Distress over brown spots defacing the perfect lawn - caused by the dog - hits homeowners hard. Sometimes, the guilty dog isn't even yours.

Fortunately, there are things you can do about it.  That may surprise you.  Contrary to popular belief, it's not the acid pH that urns those greens brown.

The acid test ...

The pH of dog urine tests between 6 and 8 - depending on what the dog ate for breakfast, how much it's been drinking, age, the dog's health and other factors.

Most turfgrasses grow just fine within that 6-to-8 range. Grass damage comes not from acid in the urine, but from the Nitrogen in the urine. Meat-eating canines ingest N as an important part of their protein diet; it's processed, then excreted in their urine. To grass, too much N is lethal. Over-feed your lawn with urea-based Nitrogen fertilizer, and you'll get the same results.

That's why the best remedy for dog damage caused by urine is the same one you'd use if you put down too much fertilizer.

Hosing down the spot after Fido is done will dilute the N. The sooner you do this, the better.

But dogs wait for no man.  Wait too long, and you'll find that saturating your soil with water won't effectively avoid that basic brown blotch.

Solution: Gypsum - Calcium Sulphate (CaSO4). Powdered Gypsum particles bind to ions in the urine.  Add water, and toxic molecules go down the drain, leaching right through the soil. To do this, soak the area well.  Then sprinkle Gypsum right over it, 1 lb per 10 sq ft of grass, like you were dusting confectioner's sugar on a cake. Repeat, and re-seed.

Female dogs worse?

If you've heard that female dogs have stronger urine, inflicting deadlier damage, know this: That's a myth. Female dogs mark less territory. That leaves more urine in a single, small spot. Its' their technique that does more daamge. Male and female urine is equally bad for grass.

You can figure that since pH is not the problem, feeding your dog special pH-changing supplements won't end yellow and brown lawn spots. Ignore ads for special pH pills, baking powder or tomato juice that claim to solve this problem. Giving more water to your dog, however, will dilute the urine, and do less damage to the grass.

Want to keep that blemished grass to a minimum?

Teach your dog to go in the same less-visible spot. Male dogs like to mark their spots and prefer small landmarks like fire hydrants. Keep water handy so you can access it as soon as needed. And make sure your dog has plenty of H2O around to spread out the N.

Some grass tends to be tougher when it comes to dog damage. Tall Fescue and Perennial Ryegrass showed almost no signs of burning in one study by a Colorado veterinarian. Clover is known for its healthy, Nitrogen-fixing benefits.  Clover also takes more abuse than turfgrass.

Too much work? One 'expert' claims to have the whole problem solved: Get a cat.

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