What will eat the roots of the plant causing it to die off and drop to the ground? This just happened to my plant.
I read that hollyhocks are susceptible to phymatotrichum root rot, a fungal infection. Because it is also susceptible to powdery mildew and rust infections, it is very important to move hollyhocks around. If you have and first year plants in the area (they are biennial in my area), move them out of the infected soil. To be on the safe side, I would wash the soil off and look for evidence of disease before replanting. bummer