My friends hollyhocks have had all the leaves infested. At first there are...

Asked July 19, 2015, 12:44 PM EDT

My friends hollyhocks have had all the leaves infested. At first there are all these small bumps and then the leaves are full of holes. They are in a flower bed with lilies and peonies and only the hollyhocks have been infested What is it and is there anything she can do? See photo.

Mower County Minnesota

1 Response

The hollyhocks have been affected by a fungal disease called "hollyhock rust." Some varieties are marketed as rust resistant. Otherwise go to the following websites for reliable information about hollyhock rust and ways to control it.

http://www.extension.umn.edu/garden/yard-garden/flowers/hollyhock-rust/
http://plantclinic.cornell.edu/factsheets/hollyhockust.pdf