Bud drop can be caused by too much or too little water or over fertilization. MSU
Flowers may be infected with blight caused by Botrytis cinerea.
Use sprays of benomyl. MSU
If leaf spots are seen, pick off and destroy the infected leaves or use sprays containing basic copper sulfate. MSU
If bacterial leaf spot causes problems, pick off and destroy infected leaves. No chemical control is listed. MSU
Leaf Rust (fungus - Kuehneola malvicola): Infection by the leaf rust fungus causes chlorosis and leaf spotting. Infection is characterized by yellow-orange pustules on the lower leaf surface. Fungicide control is usually not necessary. TAMU
Hollyhock Rust (fungus - Puccinia
malvacearum) is an autoecious fungus, requiring only one host to
complete its life cycle. Symptoms initially appear as light yellow-orange
spots on the upper surface of leaves of the various hosts. Ultimately brown
pustules develop beneath these light spots on the underside of leaves.
Pustules may also develop on the upper side of the leaves (a different
spore stage) and on stems and green flower parts. In severe infestations
leaves dry and hang down along the stem. CSU