Why do my black-eyed Susan leaves turn brown?

Answer by  mammakat (11147)

This is due to powdery mildew or one of the many leaf spot fungal issues. Don't crowd your plants, and don't water from the top. The leaves have a need to dry out and not create a very humid situation. Don't overfeed, excess of nitrogen may add to this problem.

Answer by  mahavin (589)

In black - eyed susan leaves, the common problem that would arise is the lower leaves getting brown and sometimes the leaf edges may twist to give an awkward look. This is mainly caused by the fungal disease called powdery mildew, it is caused by the oidium group of fungus or by common leaf spot fungal problem.

Answer by  worker8739 (555)

This could occur due to lack of water. During the initial planting, the roots may not have been planted deep enough in the soil and are exposed. This is a very competative plant, if surrounding plants are being fertilized regularly, possible too much fertilizer is being absorbed, causing too much stress for the plant.