Question
hw can I improve health of plant so problem won't recur next year

Answer
If the leaves have large orangish-red spots on them, then they have hollyhock rust, which a fungal disease.  If this is the case, you will need to treat preventatively with a fungicide on next year's planting.  Use Daconil all purpose fungicide and you should be able to keep the rust off the plants.  Good Luck.