Complaint Box | Dog Urine

P. C. Vey

As the new gardener for the recently renovated Washington Square Park, I never suspected that I would be spending such a large part of my day chasing people with dogs away from plant beds. As a dog owner myself, I find it almost impossible to tell something as cute as a French bulldog puppy what to do. But it is absolutely necessary if we want our greenery to thrive.

I use the phrase “Excuse me, but did you know that dog pee is bad for plants?” more times a day than I would ever admit at a dinner party. Although most people respond with surprise and apologies, there is always an entitled minority. Well-dressed and sometimes quite famous people will threaten to call the police, write angry letters or use their powerful connections to protect their inalienable right to allow Miffy to urinate with reckless abandon on every inch of our beautiful city.

Legally, it’s a gray area. New York City’s Canine Waste Law of 1978 requires dog owners to pick up only solid waste. Parks regulations state that no person shall “injure” trees or “mutilate” plants — and while dog urine does injure plants, proving prior knowledge of this and forethought would be a challenge. Ethically, however, it’s pretty straightforward: dogs should not pee on anything alive, nor do they naturally want to. The sad truth is that most owners have trained their dogs to relieve themselves on trees.

After a less than scientific survey of dog owners, it is clear that a majority think their pets’ urine is good for plants. Owners fantasize about their dogs in a forest, running free, bestowing lucky trees with much needed fertilizer. Miffy, they say, is doing the same thing here, for the less fortunate urban trees.

While urea is rich in nitrogen, and plants require nitrogen for leaf growth, urea is also rich in salt. Remember Carthage? The Romans salted the earth so that no crops would ever grow again. Salt sucks moisture from leaves and roots alike and kills beneficial soil microorganisms. Next time you’re in any park, look at the shrubs at the entrance and on corners; they all have a sad brown arc of dead leaves at the base.

More important, the nitrogen the dogs distribute so readily is in the form of nitrates. Most plants can’t use the nitrate form and must rely on soil bacteria to turn it into ammonium, the form they can absorb. Both natural and well-cared-for soils usually contain the bacterial and microbial communities to perform this function, but urban trees, like all of us city folk, have it rough. The soil is compacted, unwatered and lacking in organic material to support this activity. The urea generally stays as it is.

So while Miffy might someday help fertilize a forest tree, New York City has 1.4 million dogs and far fewer forests. I have watched a single plant get peed on 35 times over the course of a morning. That much urea can eat through bark and kill a small plant in a week. We may never know exactly how many plants and trees are killed by dog pee, but I assure you the number is staggering.

I never imagined gardening would include getting into the mind of a dog with a full bladder, yet I’ve added canine psychology to my repertory of considerations when locating plants: far from poles, away from the edges of walkways and in clumps (individuals are an easy target). My sign suggestion — “You don’t like to be peed on. Neither do plants.” — was deemed inappropriate for public display, so I hang more traditional signs over plants that are frequent victims.

But we do not want to become a society of signs and fences. Teaching dogs to respect plants is not impossible, even for the most manipulated owners — like those who tell me their pet is the one holding the leash. Oh really? I am quite positive that Miffy, given the option, would actually prefer to pee in the apartment rather than outside of it, yet you have persuaded her not to.

Rebecca McMackin lives in Clinton Hill, Brooklyn, and is a horticulturalist with New York City and a garden designer for Mantis Plant Works.