Does phragmidium rubi-idaei spread from raspberries to other plants such as holly hawks
Attached are photos of the top of raspberry leaf, and the top and bottom of hollyhawk leaves. The bottom of the hollyhawk leaf looks different from that of the raspberry, and seems to have more hard structure like that of an insect development stage. Hollyhawks show holes in the leaves as if something is eating it (maybe larvae? )I found the raspberry patch too infested to trim out affected leaves. I completely removed one Yard waste bin full of one patch, including the roots. Why? because I fear it spreading to other flowering, non-cane berry plants. Another infested patch awaits my thinning or removal of the new-non-producing canes, in hopes of getting berries this year (bushes are loaded) at the expense of next year's crop. Will that help this year's crop?
I suspect that the casual agent of leaf rust in caneberries is different from the casual agent of leaf rust in hollyhock. So thinning and removal of infested canes will help protect next year's crop. Increased ventilation within the cane patch should help preserve some of this year's crop.
For more information on each rust disease, see:
Hope this helps!