It is called an easement.All areas have them. It provides access to the power lines, sewers, water lines etc. If any utilities run down the alley and or the alley proper for fire or garbage control there must be access. An easement gives the right to access the alley for any purpose. Your dad uses an easement to drive to his garage.

Ask your codes people for what you can plant in the area and your local planing and zoning commission for what easments are shown on the alley.

Think of this as a learning experience. It sounds like you did not ask your dad about your planting before you did it. You can leave it there and hope nothing is touched since you have been planting there for several years and nothing has happened. Enjoy it for the life of the planting and move one.

Most nurseries will not take plants back after they have been planted.

Actually my dad rarely uses his garage to pack his car, how can land previouslly supporting weeds along the side of a garage help someone put their car in?

I emailed a letter to the city about it, was it the right thing to do? I hope I didnt doom it by stating its existance to them.

Good news I got someone at our nurshery who will be able to take my plants away if it comes to that, hopefully it wont, that siberian elm stump had to be growing there for ten years or more and this to me states the city dioesnt care a bit.

I'm down in NC, so laws will vary, but one of my neighbors was telling me how he was going to plant a spreading flowering plant in the easement the city has on his property. He knows that at any time they could dig it up to put in a sidewalk or put in utilities, but he removed the grass and put mulch down, and next he is going to start lantana or verbena there since it will fill in quickly. Then he will have a huge area of purple flowers alongside his garden. It won't cost much, won't have to be watered, and will look pretty. But he won't be too upset if they come and plow over it, either. You could do something like that, even in potato vine if you wanted, and also put plants in pots for variety.

I have planted lots of things on public land and generally find that nobody wants to go out of their way to kill your flowers. One danger is that regular maintenance might be carried out that would accidentally kill your flowers -spraying or mowing would be examples of this. The other danger is that some sort of work would have to be carried out that would destroy them - digging to maintain a buried pipe, repaving the alley, etc. If regular maintenance is the problem (doesn't sound like there is much maintenance in this location) then you might be able to convince the workers not to spray or mow, based on the arguement that you are already maintaining the site. If needed work is going on, don't expect the work to stop or change to accommodate your plants. Overall I wouldn't worry that the city is going to do any damage to your garden. They are probably going to ignore it just as they apparently ignored the space for years before you planted.

I've never been anywhere where the city takes care of the easement. Around here, the easement is included in the lot size, but it still belongs to the city. We have an easement in front and an easement out back, and an alley. Our garage was grandfathered in when they decided to enforce the code of no building on the easement/city land. Since our garage is right next to the alley, if anything happened to the garage, we could not put up another one in the same spot. And even though we have that easement out back, there are no utilities that are underground. You could find out if there are indeed any utilities that run back there and plan accordingly.