Well, if yer out there tendin’ to yer Black-eyed Susans and noticein’ them leaves lookin’ all spotted and black, don’t fret too much. Them black spots ain’t a sign yer plant’s a goner, but it sure means somethin’ ain’t quite right. Now, I ain’t no expert, but I been around enough gardens to know that those spots usually come from a couple o’ common culprits. So let me tell ya, real simple-like, what might be causin’ it.
What’s makin’ them black spots?

The most common reason for those ugly black spots on Black-eyed Susan leaves is a lil’ ol’ thing called Septoria leaf spot. Now, that’s a fancy name for a fungal disease, but don’t get too worried, it’s just a fungus that loves wet weather and moisture on them leaves. Them spores get spread all over when rain or water splashes up from the ground onto the plant. At first, you’ll notice small dark brown spots on the lower leaves, and before ya know it, them spots grow bigger and turn black, takin’ over the whole leaf.
Signs to watch out for
- Small round dark brown spots showin’ up on the lower leaves.
- The spots get bigger and darker, turnin’ into black blotches.
- Some leaves might get so bad they turn completely black and shrivel up.
If yer seein’ these signs, it’s most likely the Septoria fungus at work. But don’t get discouraged—there’s a few things you can do to stop it from spreadin’ too far.
How to treat them black spots?
Now, first things first—keep yer garden clean. Pick up any fallen leaves and throw ‘em away. Them dead leaves can carry the fungus, so ya don’t wanna leave ’em lyin’ around. Second thing, ya might wanna try sprayin’ yer plants with some fungicide. There’s plenty of safe ones out there, like neem oil or even a simple mix o’ water and baking soda can help. Just mix a little baking soda in water and spray it on them leaves. Make sure to get both sides o’ the leaves, ’cause that’s where the fungus hides.
Watch out for other pests too!
Sometimes, it’s not just the fungus ya gotta worry about. If ya see little bumps on the black spots, that might mean there’s a pest called a Rudbeckia psyllid suckin’ sap from yer plant. They’re not too hard to deal with, though. Just pick off them infected leaves and spray ‘em with some insecticidal soap to keep them critters away. Don’t be shy about treatin’ the plant, ‘cause those pests will spread fast if ya let ’em.
Preventin’ future problems

- Water yer plants at the base, not from above, to keep the leaves dry.
- Don’t overcrowd yer plants—good airflow helps prevent fungal growth.
- Keep an eye on the weather. If it’s been rainy, you’ll wanna check ‘em more often.
So, if yer Black-eyed Susans are lookin’ a little under the weather, just remember it’s probably them Septoria spots causing all the fuss. But with a bit of attention and care, you can help yer plants fight back and get ‘em back to their old, sunny selves. And don’t forget, keep an eye out for them pests, ‘cause they’ll sure make things worse if ya ain’t watchin’ close enough.
Tags:[Black-eyed Susan, Black Spots, Septoria Leaf Spot, Garden Care, Plant Diseases, Fungal Disease, Rudbeckia, Plant Care, Pest Control]