As with everything in toxicology, the dose makes the poison. Dog owners will know that letting your dog pee in one spot will kill the grass in that spot, but spreading the same about across a whole yard will do substantially less damage (and might actually help, depending on nutrient deficiencies in the soil). But, those same nutrients that are beneficial in smaller doses can be harmful in larger doses (which is why taking vitamin supplements is recommended against unless you have a particular deficiency). Probably, one dog peeing on a tree isn't going to hurt it much at all, let alone killing it. However, your neighbor also isn't wrong to request dogs pee elsewhere, since *enough* dogs all going in one spot will definitely kill the grass and possibly hurt the trees.


Also, animals like to mark a spot with a previous scent. A single tree can get marked by every dog on the block, while others are ignored.


The main problem is nitrogen. You can burn a plant with too much miracle grow the same way dog piss (it's no guano but it's quite high in N) burns grass and other plants. There are other chemicals and hormones but the main thing is too much 'fertilizer'.


So, if they pack mulch around the tree. Would that help? According to my few seconds of research, mulch absorbs nitrogen.


Yes, and you'll get hella mushrooms growing there, because mushrooms like nitrogen too


Depends on what the homeowner has done by themselves to treat the soil. Different trees require different nutrients and some are very sensitive. I had a tree killed due to pee. Other trees have zero issue with being a neighborhood pee stop. Different dogs also have different contents of their pee based on what they eat and how much water they drink, just like humans. Context is very much required, and while yes, having barriers like mulch do help, what the mulch is made out of will also vary it’s help level. Mulch can mean anything from fine sawdust to bark chips.


Packing mulch around the trunk of a tree is not good for the tree and will cause damage.


Not necessarily. A thick layer of mulch will harm the tree and might actually kill it. The top part of the root should be visible.


Uh what? No, mulching your trees is perfectly safe, so long as you dont build a volcano around it going up in contact with the trunk. Mulch helps regulate soil temps, reduce watering, reduce pests, and breaks down into usable organic material for the plant. Having exposed roots can sometimes be beneficial for air exchange, but generally not a good sign. That means your soil is too nutrient poor, dense, or not draining water well enough.


But in this case I am discussing the trunk. The top part of the root should be exposed to air. With no mulch nor soil covering it. I am a horticulturist, it is one of the common type of mistakes people make, causing fungal problems. > Having exposed roots can sometimes be beneficial for air exchange, but generally not a good sign. No, this is my job. You should expose the top cm or so of the root trunk on most plants I know of. In fact I don't know of any plant where it is beneficial not to.


>But in this case I am discussing the trunk. The top part of the root should be exposed to air. With no mulch nor soil covering it. >You should expose the top cm or so of the root trunk on most plants I know of. Can you explain what you mean by root trunk? I could be misunderstanding your terminology, but you seem to be using the trunk and the root zone interchangeably here. Mulch against the trunk is bad yes, can lead to rotting. Mulch on the ground covering roots? Never heard of that being bad. I worked at a nursery for 5 years, with master gardeners and educated horticulturalists all around. I live in the mid-south, what region are you from?


But read the context of the discussion. Dogs does not pee on the mulch bed far away from the tree, it pees on the trunk. The previous poster obviously meant to mulch the area close to the trunk which is a big no-no. If you ask any horticulturist they will say that. You think about it as the top part of the root closest to the trunk need protection from sunlight but what you really need to do is protect the trunk from excess humidity. That means you remove the soil or mulch from the area closest to the trunk and expose the top part of the root. Not ALL roots, the top cm so it is visible.


Yea i'm just going to chalk this up as a misunderstanding. I stated twice that mulch shouldn't contact the trunk and you're speaking as if i didn't. Btw the terms you're looking for is root flare or root collar, where the trunk meets roots.


Also marking the same tree 3 times a day for 8 years probably has some cumulative effect.


The one utility box by my apartment building has the paint worn and metal rusted where everyones dog marks it. Theres another just like it on the other side of the building that is untouched though. Dogs are weird.


Sure, but marking is just a few drops most of the time. It is not the same as the dog peeing.


Dogs will also tend to pee in the same spots as other dogs though. My neighbors entire yard was dead because every dog in our neighborhood loved peeing in their yard for whatever reason.


Exponential growth probably. One dog pees there, another dog smells that dogs pee and pees there, now they smell two dogs pee and then four then eight until that poor guys yard was the neighborhoods toilet


It's linear growth; there's only ever one dog peeing at a time, irrespective how many dogs have peed in the past.


"At a time" isn't a relevant time scale for dogs pissing. If the first dog who goes there increases the daily visitors to two, and then those increase them to four and then eight, that's not linear growth.


>If the first dog who goes there increases the daily visitors to two, Why would that be the case?


Ask the first person who came up with the hypothesis in this thread, please, not me. It's clearly a thought experiment.


Assuming the probability that a dog pees in a location is linearly correlated to the strength of the scent. Day 1, one dog pees somewhere, causing a 5% probability that other dogs pee in the same location. 20 dogs walk by and one other dog pees there, increasing the probability to 10%. Day 2, 20 more dogs walk by. 2 dogs pee there. Now it's 20%. Day 3, 20 more dogs walk by. 4 dogs pee there. Now it's 40%. And so forth.


Even a whole neighborhood of dogs completely pissing on a tree wont harm a full grown tree. Its root network is simply too large. And most of their water uptake and nutrients come from the furthest extents of the roots. A sapling or grass, or other landscaping could definitely be affected by even a few dogs. I wouldn't worry about a fully grown tree.


Grass is *highly* susceptible to the compounds in urine though. It’s just a weak plant in general, dying on essentially a whim. An established tree will be fine, though depending on physical damage done by the urine or the dogs themselves it might lose some bark at the bottom


10 dogs in the neighborhood going on walks once or twice a day.. thats a lot of "drops" either way lol


10 dogs marking the same spot twice a day is still less than a single dog produces during a dedicated session. Also there were some dogs' "billboards" in the neighbourhood where I grew up. Never saw any damage to these trees.


I've seen dogs that genuinely have to go but hold it until they find a good spot to mark and just let loose.


In my decades of owning dogs, I've never noticed them ever to just lightly mark a place that they don't also pee around.


I reply only to say on long walks my lil buddy maxes out his territory marking ability. When this happens I call it "pointin dick" like hes just pointing at stuff saying "thats mine!"


With our little boy, if we're perceptive enough, can see the singular drop he releases the majority of the walk once he's past empty.


Marking is certainly not just a few drops unless it's towards the end of a long walk.


Another example: we had far too many bird feeders up last year and aside from the mess, the plants below were ***not*** happy with all that nitrogen


Have a look at what [cormorants](https://link.springer.com/article/10.1007/s10750-015-2618-1) do to the trees and soil beneath where they nest. Note: I like cormorants


that’s interesting! but also, to answer OP’s question, as a city dweller in a neighborhood with a TON of dogs, I can tell you with absolute certainty that if dog urine ruined trees, there would be zero trees left on the block, yet all the trees are still alive and thriving


In our neighborhood the ash borer is killing more trees than dogs could ever manage.


Invasive trees and plants are killing off the native plants in my area. I'm looking at a barely lit one right now that's going to get cut back hard, sadly not down though. It's on my neighbors property.


>Probably, one dog peeing on a tree isn't going to hurt it much at all, let alone killing it. However, your neighbor also isn't wrong to request dogs pee elsewhere, since enough dogs all going in one spot will definitely kill the grass and possibly hurt the trees. Dogs like to pee on other dog's pee. So if there happens to be a lot of dogs that frequently pass this one specific tree it could do enough to upset the PH in the soil and cause problems for the tree (depending on type/age etc..)


The main problem is nitrogen. You can burn a plant with too much miracle grow the same way dog piss (it's no guano but it's quite high in N) burns grass and other plants. There are other chemicals and hormones but the main thing is too much 'fertilizer'. Dogs on dogs in one spot can definitely create issues.


I’m looking at a holly bush right now completely dead due to a beagador pissing on it for six months.


How do you know it was the dog urine that killed the tree?


Because there are two others beside it that the dog doesn’t pee on that are still thriving. I can’t be 100% sure, but it’s the most logical explanation.


> But, those same nutrients that are beneficial in smaller doses can be harmful in larger doses (which is why taking vitamin supplements is recommended against unless you have a particular deficiency) This parenthetical doesn't make logical sense unless your vitamin supplements are necessarily large doses.


Some vitamins are absorbed no matter the amount, while others are passed with the urine if they aren't needed. The former ones can cause problem if you overdose them, which is what happens when your diet provides enough but you also take supplements.




In many cities, the boulevard between the road and the sidewalk is part of the public right of way. Homeowners are responsible for simple maintenance but it is not their property.


I'd they're responsible for maintenance then they should be allowed to deny peeing on it.


I said simple maintenance. I.e. cutting the grass. Do they get to deny access to the sidewalk as well since they have to shovel it?


> So how do you communicate with a dog to tell it where it can and can't pee outside? A dog is a dog and it'll piss where it wants to No, you still own the property, it is simply subject to a public right of way. You can use it as long as it is not inconsistent with a public right of way. If the public road is closed, the property is yours without restriction.


You shouldn't ascribe your local property law and land plotting to other jurisdictions. You have no idea what the property law is on road allowances in say, Maine or Manitoba, or how they draw their property boundaries. I've looked at the property boundaries for my home on a map. I do not own the land between a couple of feet back from the sidewalk and the road.


Yeah I also think that is a very American centric viewpoint. Certainly in my country the average property would not include the pavement (the section between the road and the private land that people walk on). The only examples I can think of where the property owner also owns and is responsible for a public right of way would be some historic footpaths or on massive estates.


The sidewalk is public right but the lawn/trees/garden between the sidewalk and curb is still private.


Not in Los Angeles. http://www.wherethesidewalkstarts.com/2010/11/city-of-los-angeles-revises-parkway.html?m=1


I do not own the land between the sidewalk and the curb in front of my house. The city does and they maintain the tree that is planted there. The city by-law requires that I cut the grass and shovel the snow, but that's it.


Nope. It's not always the case. In my town, the plats all show the first ten feet belonging to the town. My old town? Same thing. If I don't mow that part I still get a fine from the town, even though it's there property. In my old town, they showed up to a neighbor and asked him "Where do you want the tree. Because if you don't pick we will." If you planted a tree in that 10 ft and then tried to cut it down? They'd fine you, even though you planted it.


https://en.wikipedia.org/wiki/Road_verge It's actually pretty common in the US at least that the area is public. It's my understanding that this is also why people can leave out old appliances and furniture on the curb and people can take it without any criminal consequences. It's been disposed of on public property.


> why people can leave out old appliances and furniture on the curb and people can take it without any criminal consequences Crimes have act & mental/intent elements that must be met. To be convicted of theft, prosecution needs to show that you not only in-fact took someone else's property, but also that you intended to deprive an owner of it. If you take something you genuinely thought someone was giving away, even if you're wrong that is not a theft. Likewise, if you accidentally walk out of a store without paying, that's not a theft.




I see - I’d say those areas are fair game for doing business. I have only seen them in people’s front yards/gardens


The concept of a public right of way disagrees with this. As a property owner you have certain responsibilities, including maintaining any public right of way on your property. People walking over your lawn and creating a trail when there is no sidewalk or using your front lawn as a bus stop does *far* more damage than a dog taking a leak, but you have no right to prevent people from using a legal right of way. All of those signs people post are entirely unenforceable. You own the property, but the public has every right to use it.


A single female dog peeing in one spot on a lawn, just one time, can leave a dead spot. If the same dog, or several dogs, come along and do it every day, that's a seriously damaged lawn. Not saying it is or isn't worse than people walking on it, but it's pretty destructive.


No fences no nothing? I'm pretty sure no law will prevent you from stopping people from entering an enclosed yard.


That's going to vary by municipality. Meter readers, mail carriers, police, all sorts of people can reasonably have cause to enter a gated property. But that's not really what's being talked about here. The strip of land next to the road isn't usually owned by private persons but they're expected to maintain it. You probably aren't allowed to fence that in.


Yeah we call that the sidewalk where I live (well, not where I live specifically because English isn't an official language... but sidewalk works well enough for a word)


Sidewalk implies pavement. US has many built-up streets that do no have any space for pedestrians to walk, but the cities own the strip of land along the road that they could in theory use to construct a sidewalk. These strips of land are unofficially used by the adjoining land owners for gardens, lawns, driveways, and so on Where a sidewalk does exist, there may be a boulevard strip of lawn or garden between it and the roadway. The city easement may reach beyond the sidewalk further into what appears as part of the front yard as well


[I found a picture of what I mean](https://i.pinimg.com/736x/ee/70/82/ee70826a9fea26851b3fce9e2bc190c3--potager-garden-yard-design.jpg). There's a sidewalk, but also a strip of land between the curb and walkway. That strip isn't owned by the homeowner but they're legally obligated to care for it. You can't stop someone from parking in front of your house, you can't fence it in, you could probably sue someone for damages if they took the plants or pavestones or whatever, and most importantly there isn't really anything you can do to keep dogs from peeing there.


one of those is not like the others. police entering the curtilage is hugely problematic. With meter readers and the such, sure. but there are a ton of cases that died because of it. If the police have the right to enter the curtilage they probably have the right to enter the house itself too. There is one case that comes to mind. the police officer walks into a gated front yard to knock on the door. up until that point he was fine. but when there was no answer he decided to look around. he found evidence of a crime near the side of the house. The court ruled it an illegal search because it couldn't be seen from the front door or path to the front door.


You can't put a fence on a public right of way... If you block or impede a public right of way, you are going to be fined by the city or county. Home ownership 101...


Well you shouldn't block a sidewalk, if that's what you're saying I agree with you. Can you explain to me, someone who's not living in the US, what specifically is a "public right of way" that we're discussing here?


In the U.S. we have a legal thing called an easement where you are legally allowed to use someone else's property for a particular purpose. Utilities (gas, cable, water, sewer, etc) have an easement where they bury lines they still own from the street to your house, for example. You still own the land, but the utility company owns the water line, and can dig it up for repair. Other common easements are houses on a rocky hill that have a septic field on the property at the bottom of the hill (which belongs to a different house), and property that has no street frontage that has a driveway easement through the property between them and the street. Easements have restrictions on both the holder of the easement and the property owner. (If there is a driveway easement through your property you can't block it, for example, and if a utility company digs up your yard to fix one of their problems, they are usually required to remedy any damage). A public right of way can be thought of as a special type of easement. In effect, it is treated as a path easement owned by the general public or local government over someone's private property. There doesn't have to be pavement or a sidewalk involved. In addition, most of the public roads in the U.S. are owned by the government, which usually includes at least 6 feet on either side of the pavement, sometimes more. (See buried utilities above). This is often referred to as the "right of way". In a suburb where there is a sidewalk, any strip of grass between the sidewalk and the road is owned by whoever owns the road, thus is part of a public right of way. (This is a generalization, everything in the U.S. varies by local ordinance, your mileage may vary)


Hah. In my country stuff is simpler. You have a (possibly non-paved) sidewalk on most roads outside your fenced-in yard that you should take minimal care of (cutting the grass, for example) but can be walked on by the general public. What's beyond the fence requires you to accept even for public utilities.


In my US town the city manager has 'Right of Way' on property within a certain distance on either side of the road. The point is the city lays electrical, sewer, storm drainage, paves sidewalks etc along roads. Usually it is around 2 or 3 meters into your property. In this right of way, the city has the right to do these things on your land without having to get your permission, though usually they will put a notice on your door a few days before. The city may also restrict you from building permanent buildings, fences, walls, etc. in that area so access to the buried lines isn't blocked. They do have to fill in after digging and reseed grass, etc. If the city needs to do something further into your property, they would need to get an 'easement' from you. This is permission to build or do something on your property. These are permanent and the survey of your property and deed to the land has to be amended to include this. You may be able to get compensation for allowing it, depending on what it is. There is a 'call before you dig' hotline in my area where you can call the line, mark where you want to dig and all the utilities have to send someone to spray paint in different colors where their lines are near the dig zone. Construction companies get fined if they don't use this and damage a utility line.


So it's all yours up until the very edge of the tarmac but a strip must be allowed for the general public to walk on? Sidewalk...


They sometimes go vertical up between the houses, especially when there's a public park on the other side and a dirt walkway, or as they're saying, a utility line running between the house


Not the same person you asked, but it's the section of grass between the sidewalk and the road.


A public right of way is the portion of your property along a road where the public has a right to access. In many places in the US, this extends 10 feet from the curb of the road, thought it can be more or less depending on where you live. You own the property and must maintain it, but you cannot prevent *anyone* from accessing it, even temporarily, without government or court approval. They are not unique to the US and are not unique to just roadways. Right of way can extend to waterways, railroads, pipelines, transmission lines, canals, etc. that run through private property.


I mean, you’re technically correct however your making this whole long argue over a (possibly) incorrect assumption that the tree was on a right of way to begin with.


We had the dog pee problem on our lawn beside the area where our sidewalk meets the public sidewalk. We mixed up a solution of cayenne pepper and water. We then sprayed the sidewalk area and the metal post of the neighbors chain link fence. Worked like a charm. One sniff and they bolted. Didn't have to spray the lawn.


what about traps?


Which portion of the private property would the public have every right to use? That is a new concept for me. Could you share some supporting evidence of this?


A public right of way is an area defined in state and local codes that extends from the centerline of the street out a specific distance that is for public travel along and includes the road itself, curb, sidewalk and normally a short buffer beyond. It grants the public the right to use anything within the right of way, even if it extends onto private property. In many places in the United States, this generally extends somewhere between 8-12' from the curb of the road. Most cities require the homeowner to maintain the property up to the edge of the curb. If you want to learn about a public right of way, just go to your city or municipality's website and they will have documentation about it. In some cities the entirety of the land within the public right of way is public land, but in others (such as where I live) property lines go right up to the street and the public right of way extends 10' into my front yard (plus another 10' utility easement). I am legally responsible to maintain it and I cannot restrict the public from using it.


Sidewalks in many towns are on private property, depending on the municipality. I own property in NC, and the property line is *the middle of the road.* Clearly I can't put a fence up in the middle of the road, and must allow use, but none the less, the property is described as that. Many cities that have alleyways, the alley is on private property, but easement is allowed to all owners of adjacent property. Property ownership doesn't necessarily convey absolute control.


This is so wrong, I don't know where to start, but let's just say that once a traveler or his belongings leave the public right-of-way and traverse onto private property, they are presumed to be uninvited trespassers unless authorized by the owner. I don't care how many people walk a cow path through your yard--you have a right to fence it off and stop that use. If the dog pissed on the sidewalk, you might have a point, but the instant it walks over and pisses on private property, it's trespassing. Since the animal is an extension of you--you're trespassing as well, and the space the animal occupies unlawfully and any actions it takes are presumed to have been done by you.


In my city, the public right of way includes but is not limited to the sidewalk. Our sidewalks are separated from the road by a ~5 foot wide section of “property”, and everything inside that section is also in the right of way. People have grass, or flower beds, or paving stones, or trees (if the city has given permission) in this area, but they cannot exclude anyone from it. Also, long-term use of a path or trail across private land can create a prescriptive easement for the public, and any member thereof can sue you for injunctive relief if you block the path with a fence.


So how do you communicate with a dog to tell it where it can and can't pee outside? A dog is a dog and it'll piss where it wants to


Super basic training and not stopping at people’s yards. Take it to a park or designated space that isn’t privately owned


It's actually very dependent on the animal (and possibly their diet). I have dogs that will kill grass outright. Had to move to artificial grass in order to have a green garden rather than a yellow garden.


Yeah, it'll vary by animal and diet, but (most of) one dog's waste is (mostly) the same as the next. And grass is less resilient to CHON overdoses than a larger organism like a tree would be.




The parenthetical is correct but not related. The problem in vitamin supplements isn't the dose. It's that there is no evidence that they benefit a healthy person in terms of any measurable outcomes, and may cause harm.


I don't think dogs peeing are going to hurt a tree, unless it's a sapling or something.


Isnt it that male dog pee is OK but female dog pee isn't?


They both contain a huge dose of nitrogen, which is generally which is what kills grass. If it rains and washes it off before it dries, it is usually fine, but doesn't matter the dog gender.


Looks like we're both right. The pee is the same but the waynthst they pee makes a big difference. Males tend to do it against a tree and disperse it, whereas females squat and deliver it all, in the same place. >Do Female Dogs Cause More Damage? >It might seem as though female dogs are the bigger culprit behind grass burns. However, this apparent sex difference has more to do with the way dogs pee rather than the chemicals in their urine. >Some male dogs tend to lift their leg and pee on standing surfaces like tree trunks and backyard fences, and they will also disperse their scent rather than in one concentrated spot. In contrast, female dogs are more likely to squat and pee directly onto the grass. Damage to your grass can occur as your dog pees in the same area repeatedly


It can damage the tree, for sure. Not one, but the next dog will add theirs, and the next... When using human urine as fertilizer, they recommend diluting 10 times. Have not seen huge number of damaged ones, to be honest. But I live on the countryside, not too many dogs. And it is surprisingly difficult to know, what kills a tree. The extra nitrogen might disturb the autumn processes and lead to winter damages, as an example. In some environments, the salt could become an issue, but have seen that only for grass two times/places.




It's fine to use, and had been used for centuries. [Human waste is a safe fertiliser: expert](https://www.canberratimes.com.au/story/6154663/human-waste-is-a-safe-fertiliser-expert/) [Reuse of Human Excreta](https://en.m.wikipedia.org/wiki/Reuse_of_human_excreta) [www.nature.com The urine revolution: how recycling pee could help to save the world](https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.nature.com/articles/d41586-022-00338-6&ved=2ahUKEwiSkfC66Kb6AhXxMEQIHQMtDDsQFnoECAwQAQ&usg=AOvVaw3we_LZQMCUBTCC2yK7reme) Just don't take a dump or a wee right on your crops.


Human feces should not be used as fertilizer. Urine, although not sterile, does not have the same pathogen issues. There are many papers on google scholar that discuss this: https://scholar.google.com/scholar?hl=en&as_sdt=0%2C29&q=human+urine+fertilizer&btnG= For example: *Microbiological quality of urine-fertilized cabbage and sauerkraut made from the cabbage was similar to that in the other fertilized cabbages.* https://www.nku.edu/~longa/classes/calculus_resources/docs/cabbage.pdf


After a little googling this seems to be incorrect. Do you have a source for that?




Urine and feces are *very* different when it comes to carrying pathogens.




Urine is high in nitrogen, and plants require nitrogen. But the problem is that it's too concentrated. If you dilute the urine, say if it's a rainy day, then the plants are actually helped by the nitrogen and phosphorus compounds found in urine. But if it's undiluted there's simply too much and it can harm the tree.


Urine is also high in sodium, which kills plant cells/roots if high enough concentration.




actually, surface pee can still harm trees. >A spokesperson for the New York City Department of Parks & Recreation e-mailed this statement when put to the dog question: When urine is added to a tree pit, the extra salt can create a crust on the soil, which makes it almost impenetrable to water. Salt also draws out water from tree roots, further compounding water loss and simulating the effects of drought.... These problems are exacerbated because dog urine attracts more dogs to do the same. Tree pits are very limited in water, air, soil, and nutrient availability. The soil is also very compacted, which further intensifies these limitations and damages. Therefore, it’s important to limit animal waste in the pit to help keep the tree as healthy as possible so that it can fight off pests and diseases and grow to its full potential. https://www.bloomberg.com/news/articles/2012-08-30/why-you-shouldn-t-let-your-dog-pee-on-trees


It absolutely can. It can cause a disruption in chemicals and nutrients at the surface or the bark of the tree, each that has its own microbiome










Lots of good comments, I'll add another, qualified with a question: Does it rain a lot where you live? You're in the NE on the coast, so I assume it does. Which means the risk of urine to the trees is probably low. Here's why. Dog urine (like most mammalian urine) contains urea (and other nitrogenous compounds like allantoin). This is rapidly degraded to ammonia (NH3) in the soil by bacteria, which is quite alkaline and can cause damage to plants in high concentration. Fortunately, NH3 is rapidly protonated in moist acidic soils to become more stable ammonium (NH4+). Ammonium itself is an important nutrient for plants and mildly acidic. Ammonium is also biologically labile and undergoes oxidation to nitrate ( NO3-) by bacteria in the soil via [nitrification](https://en.wikipedia.org/wiki/Nitrification). This process releases protons which further acidifies the soil. Here's where the rain comes in. Very broadly, humid environments (those receiving consistent rainfall) tend to form acidic soils (for several reasons we won't get into), while dry environments accumulate salts and form alkaline soils. The rain in your area will ensure that the ammonia is converted to ammonium, which is highly soluble. Some will be exchanged and retained as a nutrient in the soil, but the rain will wash a lot of it away. Much of the remainder is converted to nitrate: NO3- is both highly desireable by plants and preferentially taken up a nutrient, and also highly soluble. Consequently, it is not well-retained in moist, well-drained soils. Meaning that unless the tree is receiving mega doses of urine, it's unlikely to suffer much and might even benefit from the fertilisation effect. Now if you lived in a dry area, or a wet area experiencing a drought, the ammonia will accumulate as the water evaporates from the urine. Repeated exposure from new urine will concentrate the ammonia and can cause localised damage to the plants due to the high pH. For this reason, semi-arid to arid areas are highly sensitive to frequent urination by animals. You might even see white crusts forming on the soil/tree from other evaporated salts accumulating (Calcium, magnesium, and sodium chlorides, sulphates, and carbonates).


Where you get these expertise?


While the nitrogen in dog urine can be beneficial for plants, the high concentration of nitrogen can actually burn and damage trees. In addition, the acidity of dog urine can also erode the bark of trees, leading to further damage.


The nutrients in urine need to be processed (aka, broken down biologically) before they're actually accessible as nutrients (fecal waste is a whole other thing, though). Pee, on it's own, is not "good" as a nutrient; it has to rendered accessible to plants. There are some intersecting issues here. The urine itself is going to be a vector for various things living in your dog. *Possible* disease or pathogen vector. As a chemical it's going to be mildly acidic and possibly mildly poisonous; and when it finally is broken down that will be a minor nutrient spike that may be completely unnecessary (or desperately needed). I think the actual big impact is that urine is *also* a marker to other dogs. Your dog pissing on a tree isn't going to kill it, but it might tell all the other dogs to start pissing on that same tree. We actually *do* know that the rhizosphere, a space a fraction of a millimeter around the roots of plants, is loaded with life and the bacteria and fungi living there are crucial for proper nutrient transport. Those are *absolutely* vulnerable to chemical changes. As tiny organisms, they have short lives and repopulate quickly--but again, the cumulative impact of this happening a lot is more important than one bad day for the bacterial population. But also, it's going to depend on how severe the harm needs to be before you take it seriously.


The issue at hand is when a dog pees on a tree, so does every other passing dog. And they do so multiple times a day. Chances are very slim that it will harm the tree as they are peeing on the trunk and the tree does not uptake any nutrients from that area, but at the drip line. It's more an issue of smell and annoyance.


Actually the ammonia in the urine can harm the bark if there are enough dogs peeing. You can see this on NYC street trees, unfortunately.


The bark is only a protective coating anyway. Harmed bark does not affect tree health until the harm passes past the bark and effects the cambium layers.


Dog urine can dehydrate tree roots: salts in dog pee can make the topsoil harder for water to penetrate, meaning the tree's root doesn't get as much water as it needs to be healthy. Dog urine can lower the soil's pH value: trees need soil at a certain pH level, but dog urine can lower the levels.


Small dogs have stronger urine then bigger dogs. If it's constant it's possible but trees are very hardy.. I'm a landscaper and I've seen a few smaller trees that were just planted die from this but the big established ones will be fine


I work as a civil engineer in some dense, urban environments in Miami. So lots of rain. Dog piss has completely decimated shrubbery and groundcover material, and also affects full size palms and trees. The trees will live, but they don't look their healthiest. The smaller plants die. The planters nearest the entrances/exits of high-rise residential buildings suffer the most. The owners have had to replace the decorative groundcover with plain old mulch.


Non-expert opinion here: Medium / Large trees will be fine, small trees still establishing a root system will be hurt especially if drip line is still close to base of the tree. One dog won't hurt it but multiple dogs will often pee in the same place.


Mulching would go a long way. That way the pee gets absorbed by the mulch and diluted when it rains and finds its way to the roots.


Urine contains lots of nitrogen. Nitrogen is good for plants to a point, but excessive amounts of nitrogen become toxic. Much like salt in humans- we need some, but too much causes long term health issues. WAY too much causes acute poisoning.


In my lawn (I have 2 dogs), the spots where the dogs pee are dead grass, but the circle around is really thriving grass, much better than the rest of the lawn... so basically I have a lawn that's 1 inch high, with brown dead spots in it, surrounded by 4 inch high grass... until I cut it of course oh yes, it does kill small plants and trees for sure... But a 100 y old oak tree doesn't have to worry


Follow-up question -- I was told at one point that it's better for plants if urine (in this case human urine) is not deposited on trees because it contains salt that deer will try to lick up, and physically damage tree bark or other tree surfaces in doing so. Anyone have an idea if there's any truth to that?


That deer will drink urine is true, but I have no idea if deer licking trees is remotely harmful in itself. The pee itself is harmful because it's too concentrated. I read somewhere that if it were diluted about 10:1 with water, then it's actually beneficial (nitrates).


It will damage small bushes, but takes more than just 1 pee. The problem is that if 1 dong pees, all dogs are gonna pee in the same spot lol. I know for a fact that urine will kill a bush because when I was younger, I used to step out the back door and piss on a single bush thinking I was watering it, then it started to die, so I kept pissing on it to see what will happen. The grass around the bush also died.


So much overthinking the problem in this thread. If it's a very young tree and it's getting peed on constantly, maybe but unlikely. If it's an established tree, no. Just look to nature. If you set up a trail cam on a known coyote path you'll sometimes see upwards to 20 animals mark that spot in a single day. The trees in that area are completely fine. If animal pee really messed with trees, our forests would look a lot different.


My weimerainer killed two cherry trees, a nectarine tree, and a pear tree, and a rose bush. It took 15 years. First tree was like 2-3 years of daily use as his only pee spot. The others does over the next 5-6 years because he rotated a bit more. The rose bush only took like a summer to kill. He was a big dog and wasn’t just marking, he was letting out full bladders 3-4 times a day all year round. But yea it can and will kill your trees if it’s a lot of urine. The soil can only filter so much before it’s saturated with urine crystals. Edit: these trees were anywhere from 5-12 years old. Not huge oaks by any means, more like 5 inch trunks and 15-20 feet tall.


An Aussie told me a story once of a camp he was at with all young-ish guys. He said they would, "Go out, get on the piss & upon return all urinate on the same lemon tree." He said after a whole summer the tree was dead. :-(


Animal urine in general has nitrogen that is good for plants. One spots only being used can hurt the grass. But tree roots do not get nutrients from the base but from a wide area deep in the ground. Unless it’s a little sapling and it’s changing the ph of the soil or physically disturbing the soil it shouldn’t be a problem. Not peeing in the same exact spot is best for plants in general.


It all depends on the following: - the number of dogs peeing on the tree - the frequency of urination - the amount of urination - type of tree and the nutrients they need - the size of the tree - how established the tree is in it’s current spot - existing soil contents/nutrients - treatment on tree done by treeowner/caretaker (chemicals or natural treatments that can interact with urine) - dog’s hydration (concentrates the pee when dehydrated) - what the dog eats (changes the nutrients it leaves) - weather/rain frequency (less rain means the tree will absorb your pee as liquid more than groundwater) - other plants around the tree - other things not listed here Some trees are incredibly sensitive - even just on the bark. Some trees wouldn’t notice pee like that because they have been around for years. Not all trees are the same or all trees would grow happily in all types of environments. Newly planted trees would be sensitive to pee because they are generally pretty sensitive as they establish roots, although most people use those water tree bags for new trees in my area. A giant oak might be fine with pee, but it can also discolor the bark. A newly planted sapling would probably die. A one to two year old plant would probably struggle. Context is required to answer yes or no, but lets just say “yes, it is possible that pee will harm a tree.” It will not harm every tree, and it’s still a pain to have trees you are trying to get to fill out on one side never grow in because dogs keep peeing on it in the same spot over and over. My rule is: keep the dog off property that it looks like an individual has to care for or spend money on caring for, unless you want to help them with that somehow.


Whips, in an urban area, with lots of cover (I.e. little rain), and poor soil *might* be affected by heavy urination. But I'd be surprised. As with a lot of things in America it's insane hysteria to assume that dog wee will damage a tree.




So likely the tree is getting ammonia poisoning. Yes it can kill the tree. As others have pointed out when dogs mark it's basically a bullseye target for every single animal in the area, not just dogs. Cats, dogs, opossums, racoons, etc will mark over it to get rid of the scent. Up north you can add bear, elk, mountain lions as well and having a bear empty the tank on a young tree can be a deathblow. Especially if it's a lemon tree as the rapid change in ph can kill the roots. Ammonia isn't as bad as say bleach but in large amounts say 4 dogs a day every day, yeah that will kill a tree, even a fur tree would probably get dead spots in a week or two.