Hollyhock leaves dying
Hi, can anyone tell me what's happening with my Hollyhock leaves. This has started happening since I put them outside to harden off. I know Hollyhocks are susceptible to rust but it doesn't really look like that, judging by the pictures I've googled and there don't seem to be any insects present. I've take off the affected leaves in the hope that this will help but I really have no idea. Any advice would be most appreciated. Thanks.