|I have a few Rudebeckia(Black eyesusan type) with brown spots taken over the green foliage. Is this a fungus? What should I use to control this ? they look diseased!!
|Brown spots on leaves could be a sign of a fungal infection, or sunscald from drops of water magnifying the suns' rays, or the remains of an insect feeding (closely inspect the undersides of the leaves for evidence of pests). Without knowing exactly what the problem is, I hesitate to make control recommendations. You might want to put a few of the affected leaves in a plastic baggie and take them to a well-staffed nursery. Helpful folks there should be able to recognize the problem and make control suggestions.'
Best wishes with your garden!