Know It and Grow It
Wed, 06/17/2015 - 1:44pm
mfodness
If you have rudbeckia goldstrum, the perennial black-eyed Susan, and you are noticing angular black spots on the leaves, your plants are being attacked by a fungus called septoria leaf spot. To prevent that disease from totally destroying the beauty of the plant, you need to spray both upper and under sides of the leaves with a fungicide.