Is it OK if I let my dog pee all over somebody else’s shrubbery?

Dear Cecil: This afternoon I was walking my two male dogs in front of a local condominium. As they lifted their legs to a hedge next to the sidewalk, a man in a business suit walked by and said quite loudly, “Don’t let your dogs do that! We work hard to keep this property looking nice.” Then he just stood there expecting me to reply. I started to walk away and he continued to stand there as if he were guarding the building. Finally, I turned and said, “I really don’t think they were hurting anything.” Of course, he exclaimed, “Well, I do!” and stamped off toward the building. I then yelled, “Well, you probably don’t have dogs!” The point of all this is: scientifically speaking, does dog urine hurt hedges (or bushes and trees, for that matter)? Let me say that I can understand why people object to dogs defecating on sidewalks or in their yards. But what’s the harm of a couple squirts of pee-pee? P.S.: Don’t bother answering this if you hate dogs and think everything they do is wrong. Etta B., Baltimore

Cecil replies:

Dogs don’t bug me, Etta, it’s their idiotic owners. It’s hard to believe you’ve gotten through life without noticing that dog urine can cause grass, shrubs, and other plant life to turn brown and wither. This charming phenomenon is called “urine burn.” It’s caused by the ammonia and urea contained in doggie water (and, for that matter, in the urine of all mammals). Urea and ammonia are both good sources of nitrogen, an important fertilizer. But they’re simple compounds and they break down so quickly that the lawn, hedge, or whatever basically ODs on the stuff. Similarly, if you use too much inorganic nitrogen fertilizer, you’ll get “fertilizer burn.” The urine also makes the soil too acidic. The only cure is to dig up the ruined patch and reseed.

Well, you say, will just one dose wreck the local flora? It depends. One dose is certainly enough to do strange things to the grass. On a lawn where dogs have had free run you’ll see numerous funny-looking tufts where the grass is much taller and greener than elsewhere, having been fertilized by a passing canine. No big deal, you say — mowing the lawn will level things out. Here and there, however, the tufts may consist of a brown patch with lush growth around the fringes. The lush part got the optimum dose of fertilizer while the brown part got too much of a good thing. Mowing is not going to help this problem; time to get out the spade.

Chances are the tufts are the work of female dogs, which like to do their thing out in the open. Male dogs, by contrast, prefer some vertical landmark, such as a tree or shrub. These are generally hardier than grass, and one jolt won’t kill them. But you seldom get just one jolt. Male dogs use urine to mark their territories, and they like to return to the same spot again and again. In addition, when other dogs smell a freshly irrigated canine boundary marker, they often feel compelled to make a contribution of their own.

Male dogs have been known to do in bushes, hedges, and, in one case at least, a pine tree. So keep your mutts off other people’s property. The dog may not have a clue, but it’d be nice if the owner did.

Cecil Adams

Send questions to Cecil via cecil@straightdope.com.