Diagnosis
Diagnose: Leaf Spot on Black-Eyed Susan
Use these observations to decide what to check next.
Septoria leaf spot when dark lesions begin low and move upward
Irregular purplish-brown to black spots on lower leaves, sometimes with gray centers or one straight edge along a vein, fit Septoria. Spots confined between small veins suggest bacterial angular leaf spot, while white surface growth points to powdery mildew.