Yes, Hollyhocks. One year I used mancozeb and that worked. Also I have crabapple seedlings, a few which get rust but I don't treat. What do you have rust on?

Well, I bought a serviceberry tree from a place around my house. I had the guy order it for me because he didn't have it in stock. When I picked it up on wednesday I didn't notice it. Yesterday, after really getting a good look at it it had all the tell tale sign of rust.

I haven't planted it yet, and I'm not going to because I'm going to return it today. I was just wondering if it could have infected anything I already have in my garden. It's about 20' from anything else in my yard.

I was going to plant it close to my neighbors apple tree's but after reading up in rust I don't think it's a good idea. She doesn't take ggod care of her tree's and they are loaded with a spotting leaf diease.

Well, you might have infected your neighbor's crabapple! Really, no one can guarantee that for sure. In order for the rust to spread, a host for that particular rust needs to be present. Do you grow anything that might be affected by the same type of rust? Besides that, how do you know which particular rust you have? Here is one link that lists a few strains and what they attack.
Get rid of it. This year, I didn't spray my hollyhocks. They are just about to bloom and they look so bad, I am going to chop them down.

Here is a link that might be useful: Gymnosporangium rusts

What is rust? My flowering crabapple tree lost leaves early last fall and now many limbs are dead. I have a lot of suckers sprouting up from roots. A few leaves are yellow with green spots. I am new at this ... any advice would be appreciated!