First, my sympathies. Second, my suggestion: I think you may find yourself getting fed up and start cleaning up that mess yourself. It's not a great option, but I think your back is up against a proverbial wall. I tried removing blackberries by digging them up, but I guess I didn't get all the roots, so they grew back. I've heard that you can apply chemicals to the stalks and that should kill them. It doesn't seem fair that you now have a huge project on your list, but I don't see an alternative. You'll be protecting your investment in your home.

So that I'm clear, is the pile o' festering crap on common land (alley) or on private property? I think Lily777 nails it, if no one else is willing to deal with this it's down to you, but there's a big difference to putting your shoulder to the wheel in the alley versus on someone else's property. I wouldn't go on their property without written permission detailing what you are and aren't allowed to do.

Yeah, it's common property being right in the alley. That's why I tried calling the city to find if they would spray the invasive stuff.
Before the development came in, the area on the other side of the alley where last house threw all their leafy stuff became full of ailanthus saplings and only there. At least when the developer did earthmoving, the trees were scraped off.

I mentioned that the alley is mowed starting just past this deadend hump. Developer put in swale with a drain there which now catches all the junk plants. What was well kept and grassy is difficult to maintain as mowing crews don't do anything. Apparently I get to do that to. It's so frustrating.

Sujiwan,

1) Have you tried to talk to the owners?
Possibly they would be willing to remove the stuff once you confront them. Either way, you must have their permission before going on their property.

2) When you speak to the city, there are several key word that might get their attention:
"attracting rodents"
"blocking access to thoroughfare"
"causing drainage problems"
Even if you have to fudge the truth- often it's the only way to get the city's attention.

3) Time for a camp fire...just kidding (not really:)

If I were in your shoes, and I didn't think they'd immediately go back to throwing crap in the alley, I'd just call someone like 123 Junk to come out and haul off the pile and be done with it. A couple hundred bucks versus trying to keep out the weeds, not to mention seething every time I go by?