How to cure Hollyhock rust?
Hollyhock Rust is caused by the Puccinia malvacearum fungus. It is little orangish-brown colored flecks that cover the underside of plant leaves. The tops of leaves will develop yellow spots. It is caused by damp humid conditions. Make sure that your plants have a good air flow around them by not planting them too dense. To control by chemicals, the fungicides tebuconazole (Provanto Fungus Fighter Concentrate), tebuconazole with trifloxystrobin (Provanto Fungus Fighter Plus, Toprose Fungus Control & Protect), and triticonazole (Fungus Clear Ultra) are officially approved for the control of rust diseases. Alternatively you can try to control the disease manually by removing diseased leaves and not planting other plants from the same plant family nearby for example Abutilon, Hibiscus, Lavatera, Malva etc. Do not use the seed from infected plants