Canadian Gardening: Disease?, 1 by cybercrone

cybercrone wrote:
Hi all:

I have a very distressing situation. A tree down the alley behind my house started getting this stuff that looks like splashes of white paint that someone has tried to wipe off. Soon the leaves were brown and curling. That was 3 years ago.
Last year my maple tree started having this stuff, and this fall it has spread to some plants in all my garden areas. I foolishly didn't find out about the tree, since I thought it was just a 'tree thing' and would be confined to that.

I have no idea what it is - nor do I have any idea what the type of people who can diagnose and treat these kinds of things are called. Or how expensive they might be.

It seems to be spreading around the neighbourhood, and is destroying a small rosebush I have been trying to get started between my front stairs and my neighbour's.

Does anyone know what this thing is, or who I would call to get it 'fixed' - and how I find out if I can (legally) request that my neighbours treat their plants and trees too? Is there anything I can do myself to treat this?

I just did my fall yard cleaning today, and am about ready to sit down and weep about this situation.

Thanks for any suggestions or education.

I will post 4 photos.
~marilyn