Hawthorn rust?

My husband planted this Hawthorn---I think it is a Washington Hawthorn (he isn't sure). There are areas that swell up and look horrible. Maybe it's some type of apple cedar rust?

What do we do about it? Can we get rid of it or will it come back each year? Does it hurt the tree? Is there a preventative that we can do in the spring to keep it away? The tree is still young. Should we try another variety of tree? We're concerned because as it gets bigger, we may not be able to treat it ourselves.

Will this spread to other trees in our yard? We also have Winterberry hollies and a Seven Sons tree. Our nearest neighbors have Maples and a Willow.

Thumbnail by valrita

Another picture. The tree is about 7' tall. It hasn't flowered yet. I think it tried to flower this year but the ugly swelling stopped it.

Thumbnail by valrita
Dublin, CA(Zone 9a)

I think this is one of the group of "cedar apple" rusts, Gymnosporangium. They are interesting in that they require two hosts, one from Rosaceae family (apples, hawthorns, and quince are common hosts) and one host that's a Juniper (many junipers are confusingly called cedars, hence the common name of the rust, but to be clear, as far as I know these rusts only infect Juniperus species, not Cedrus which are the true cedars). Here's a website with some info--the best control is to plant varieties that are resistant to the rust: http://www.urbanext.uiuc.edu/focus/cedarhawthornrust.html

The Woodlands, TX(Zone 9a)

That is quince rust AKA cedar-quince rust. Here's more information:
http://www.oznet.ksu.edu/path-ext/factSheets/Trees/Hawthorn%20and%20Quince%20Rusts.asp

It does resemble the pictures of quince rust. That website was very helpful. I was sad to read that there really aren't any resistant varieties of Hawthorn. I'll break the bad news to hubby tonight.

Thanks to both of you for taking the time to answer and for the websites. They were both helpful.

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