My neighbor just planted normal (full-sized) Swedish Aspens in 55 gallon, unpainted aluminum garbage cans, and then placed them on a concrete path where they'll get most of a full day's sun.

I think this is a bad and potentially dangerous idea, but I need help explaining to my neighbor all the reasons why.

Some possibilities, but by no means an exhaustive list:

1. Wind. These are almost surely going to tip over in high winds once the leaves are out. They are currently about 20 feet tall. And they are near above-ground power/cable lines coming into my house, and my neighbor's. Watch out.

2. Heat. The trees are going to fry in metal garbage cans in the summer heat (it is routinely in the mid 80's, low 90's where we live).

3. Water. It will be a huge pain to keep these things adequately fed all year and watered in the summer.

(I am leaving aesthetics off this list, because I'm a "to each their own" kind of person, but if I weren't, that would be number four).

Any other reasons I can add to this list, or am I way off base here? I'm not afraid to admit that I'm wrong, but I don't think I am.

All thoughts welcome.

Thanks.