Steven Wachs wrote:
i had problems with Hawthorn. I have Junipers and Crab Apple. I had a few
Hawtorn in training ,but it developed this odd growth which I think was rust.

Probably quince rust; it "wreaked havoc" on my amelanchier bonsai,
causing gall-like swellings. See
http://www.oznet.ksu.edu/path-ext/fa...ce%20Rusts.asp