Downy mildew causes pale greenish or reddish, irregular spots on the upper sides of leaves. The undersides may be covered with a soft moldy growth. Young plants are especially susceptible. The disease is a bigger problem in cool damp weather. Remove infected plants, use adequate spacings and provide good light exposure and air circulation. No chemical control is listed.
The wilt which attacks china aster also attacks bachelor button. Plants affected at blooming time have pale yellowish green leaves. The lower leaves wilt or plants may develop a one sided wilt. A thin coating of rose or pale pink spores are on the stem near soil level. Do not compost diseased plants. No chemical control is available.
Rusts attack bachelor button covering the leaves and stems with brown pustules. No chemical control is listed.
The verticillium wilt fungus infects the veins of the plant causing death. Avoid infested soil and remove diseased plants as they are seen. No chemical control is listed.
Stem rot causes rotting of the lower stems then upper portions of infected plants wilt and die. In wet weather a cobwebby growth develops on the lower stem. Both seedlings and older plants are attacked. No chemical control is listed.