By Kirk84
United Kingdom 
Can anyone help me with me poplar rust infection? I'm getting rid of the leaves as soon as they fall. The tree first got the rust late last summer. I feared it would come back straight away in the spring with the new growth but it has been fine and we'll all summer. However, the rust came back late summer/early autumn. Can I do anything to stop it happening again next year?
7 Nov, 2015
Answers
Thank you for the quick reply. Would the alternate host show rust as well? And I take it the alternate host could be in a neighbouring garden?
7 Nov, 2015
That's correct Kirk.
remove the fallen leaves and bin them not compost them. then at least you are reducing the amount of rust spores in the environment.
7 Nov, 2015
Rust is a parasitic fungi and like many parasites, both animal and vegetative, they have very complicated life cycles. So, if you are looking for complete eradication, that might not be possible. How the rust spore introduces itself into the host plant is a fascinating story if that sort of thing interests you.
7 Nov, 2015
Depends how big the tree is, it isn't really practical to spray a very large tree thoroughly.
More info here - there's probably an alternate host for your rust infection nearby, but removing it may not solve the problem because the spores are airborne, so another alternate host in the vicinity will still be a problem. Doesn't usually kill Poplars, just makes them look unsightly, and its worse in some years than in others.
https://www.rhs.org.uk/advice/profile?PID=271
7 Nov, 2015