Black Eyed Susan leaves

Asked July 29, 2020, 2:21 PM EDT

For several years the leaves on my Black Eyed Susans have gotten spots and then dried up. It doesn't seem to impact the flower blossoms. Last fall I removed most of flowers (Black Eyed Susans and others) from the garden thinking they might need more airflow. This spring I put new hardwood mulch down. I continue to have this problem with the Black Eyed Susans I have left. I'm wondering if I should remove them all and start over. If I do this, do you think something needs to be done to the soil, or will removing the plants and putting in new ones solve the problem? Thanks!

Hennepin County Minnesota

3 Responses

Hi there--
It looks like this is Rudbeckia Leaf Spot.

The non-chemical way to deal with it is to clean up the leaves really good in the fall. It doesn't really harm the plant, though it's ugly and it might die back a bit earlier in the fall.

It looks like you could use a fungicide (see the article) but it's not really necessary.

I found a non-research based article that just suggested planting other stuff in front of the rudbeckia so you don't have to see the leaves. Kind of a novel answer.

If it were my garden, I'd try the cleanup route a couple years before the fungicide.

let me know if you have any questions!



Thanks for your quick response Sue!

Since I have cleaned my garden out the last several years and the plants are watered by drip line, I think it's time to pull them. This garden is in front of the house, (not really keen on the idea of planting things in front so the leaves can't be seen) so I think I'll move the flowers to a wild area in our backyard because the blooms are still beautiful.

So from what the article says, it seems that I won't need to do anything special to the soil when I plant there again. I'll probably just stay away from Black Eyed Susans in that area. Does that make sense to you?

Thanks again!
Karen

The back wild area would be lovely--pollinators love them.

It does seem like the article says just pulling them out would be enough. I'd be sure to clean up any stray leaf waste you find but other than that, you should be good to go. If you wanted to wait to put something else in until this fall or coming spring, that wouldn't be a bad thing, I'd imagine--give stuff time to decompose but it doesn't sound like it's a big deal.