Birdy,
I have the exact same problem you describe (tree pit in Brooklyn serving as the neighborhood dog toilet) only now my not-yet-mature street tree seems to be suffering and I have a baby tree in a nearby pit I'm worried about... What steps did you try? What worked and didn't?
Paghat and others,
So many great ideas--THANK YOU!

On Tue, 12 Sep 2023 08:42:26 -0700 (PDT), Jess Richards wrote:

> Birdy,
> I have the exact same problem you describe (tree pit in Brooklyn serving
> as the neighborhood dog toilet) only now my not-yet-mature street tree
> seems to be suffering and I have a baby tree in a nearby pit I'm worried
> about... What steps did you try? What worked and didn't?
> Paghat and others,
> So many great ideas--THANK YOU!

I've read that napthalene (moth balls) discourages cats from using a
location as a toilet, so maybe it would work for dogs too. They have a
pretty strong smell, so they might also discourage the human leading the
dog. :-)

On Tue, 12 Sep 2023 08:42:26 -0700 (PDT), Jess Richards wrote:

> Birdy,
> I have the exact same problem you describe (tree pit in Brooklyn serving
> as the neighborhood dog toilet) only now my not-yet-mature street tree
> seems to be suffering and I have a baby tree in a nearby pit I'm worried
> about... What steps did you try? What worked and didn't?
> Paghat and others,
> So many great ideas--THANK YOU!

Some ground covers that might work, depending on whether they would
survive in your climate, and how willing you are to inconvenience
pedestrians. Lantana, cat's claw acacia, gorse, heavily thorned roses,
blackberries. They are actually shrubs, all have thorns, and are nasty to
deal with. They are very invasive in the right climate. An actual ground
cover would be what I call goat's head thorns. I don't know the actual
name or the latin name. Their seed is like a caltrop, with a spike always
facing up. They survive drought and frost, not sure about freezing. The
thorn penetrates bicycle tires easily, and is a real bother wherever they
are found because of the continuous flats. So, you are doing social
damage if you use them, but dogs will not walk where they grow after the
first time one goes in their paw.

In article <5dnNM.973$t8qe.690@fx03.iad>, someone@somewhere.monster
says...
>
> > Birdy,
> > I have the exact same problem you describe (tree pit in Brooklyn serving
> > as the neighborhood dog toilet) only now my not-yet-mature street tree
> > seems to be suffering and I have a baby tree in a nearby pit I'm worried
> > about... What steps did you try? What worked and didn't?
> > Paghat and others,
> > So many great ideas--THANK YOU!
>
> Some ground covers that might work, depending on whether they would
> survive in your climate, and how willing you are to inconvenience
> pedestrians. Lantana, cat's claw acacia, gorse, heavily thorned roses,
> blackberries. They are actually shrubs, all have thorns, and are nasty to
> deal with. They are very invasive in the right climate. An actual ground
> cover would be what I call goat's head thorns. I don't know the actual
> name or the latin name. Their seed is like a caltrop, with a spike always
> facing up. They survive drought and frost, not sure about freezing. The
> thorn penetrates bicycle tires easily, and is a real bother wherever they
> are found because of the continuous flats. So, you are doing social
> damage if you use them, but dogs will not walk where they grow after the
> first time one goes in their paw.
>
>

I would try an electric fence with wire about 6 to 12 inches above the
ground.