Disease of the week: septoria leaf spot of rudbeckia
Photo courtesy of Purdue University
The state flower has me in a state.
My rudbeckia "Goldstrum," otherwise known as the Black-eyed Susan, is overcome with black spots on all its leaves. They spread and grow, attacking the stem and turning the entire plant into a crispy dark mess.
This is the third year in a row for this fungus, known as septoria leaf spot, and it is spreading despite my best efforts. I have been removing the infected plants and treating the ground with a liquid copper herbicide. And I sprayed the new plants regularly as soon as they emerged. But apparently I was not attentive enough.
My answer: rip out the Black-eyed Susans and replace them with another variety next year.
I am growing less and less patient with finicky plants. If you are vulnerable to mildews, rusts, wilts or fungus, you are out of there.
I don't mind working in the garden, but I am not running a sick bay.
Comments
Yup. My Susans have that, too. I could just rip them out and let their pushy neighbors, the Tiger Lilies, wander in. I could also dig up a new spot for them, but sigh it's a little tiny yard and once I allow for the soggy spots, I may be out of space.
Anyone know how Susans do in swamp-like conditions?
Posted by: Eve | August 6, 2009 9:39 AM
I grew Susans with a drip hose running on them virtually all summer a few years ago. They grew like wildfire. They might do very well in soggy soil.
Posted by: Dave Wolinski | August 6, 2009 2:44 PM
I'm devastated. I liked the way they looked around my old log house in Laytonsville, so much that I added several more plants last year. They are so showy and cheerful, and "natural" when healthy. Do you have any suggestions for a reasonable late summer bloomer to take their place?
The fungus seems to be specific to the rudbeckia.You might try a different variety of what we generally call the Black-eyed Susan. Or try coneflowers, which have that same long-blooming quality but are made of tougher stuff. There are some wonderful colors now -- Susan
Posted by: Toni | August 27, 2009 10:23 AM