Just looking for more information regarding treatments for Rust. I have a Washington Hawthorn (Crataegus phaenopyrum) and for the first time EVER I have trees afflicted by this fungus. My Hawthorne is afflicted the most and its spread to a CE and an Ume. I’ve treated with fung-onil followed by copper fungicide. There is/was so much rust on the hawthorn I removed whole branches of secondary and tertiary structure. This plant flowers, however, I obviously wont get any this year.
I think I’ve contained the infection on the Ume and CE as I’ve seen no further progression of the disease on those trees. The hawthorn, howeve,r was literally red in color because of the rust infection. It is quite strange this happened as I used dormant sprays and lime sulfur through the winter to be more proactive. I seldomly apply preventative treatments… Has anyone successfully combated a severe rust infection? If so, what was your treatment protocol?
Not sure what else to do at this point, I’ve isolated the hawthorn from the rest of the garden. Thoughts and suggestions appreciated.