the right forum to post these images, I'm sure the thread will me moved to a forum deemed more appropriate by Eric or Daniel.... I was taking some pictures this morning in our sideyard where we did some work on a couple of rotted birch stumps. We cleaned them out best we could and then set about to line them with draped hypertufa to create a scene that would be a little longer lasting. In the process of taking the picture I spotted what initially looked a rotting Sedum blanca but a closer inspection revealed what you see in the pictures attached. What am I dealing with, how readily does it spread, and most important, how to eradicate what I suspect may be fungal in origin...
I've never seen this unpleasant condition on it before but FYI the afflicted plant is Sedum spathulifolium 'Cape Blanco'.
I don't know what we are looking at. It seems the things are on the sempervivum and on the stone itself. Almost looks like baby aphids or something. Closer photos or other descriptive detail might help. A slime mold? It doesn't look pretty, but not sure it will be so damaging to the plant. Looks more like it is just on it rather than infesting it.
Eric, you're right. It looks like it's attached itself to the perimeter of the sedum, I have attached another picture of the bottom side of a sempervivum we removed, perhaps it tells more to somebody... The plants with the worst infestation were quickly dispatched to the garbage, not the compost... I'll go out and see if I can spot some remnants and take some more pictures, this time with the use of tripod so I can concentrate better on the focus area.
Upon close inspection and higher magnification you get a better image. Now that I've seen they're still there I'll take a knife and scrape some of to put onto a sheet of paper and hopefully I'll be able to get a good macro shot!
I posted this on another forum - Houzz- and got a response that suggested Sedum Stem Rot, an anthracnose fungus called Colletotrichum. Check this. Since originally posting this I took a couple of macro shots of the fungus attached to the gravel, this being one of them.
I do not have an answer but I checked my similar plant and it looks fine Is yours planted in a tree stump ? I wonder if that’s related to the cause of this strange condition Your garden looks very nice - I noted your website and admired your detailed list of hostas I like Midwest Magic which does well at the coast too. Midwest Magic Hosta (Hosta 'Midwest Magic') at GardenWorks
GS, I recognize this will be off topic but you asked the question... Yes indeed, we have 2 birch stumps in our sideyard that showed major signs of internal rot last fall -we'd used them as pedestals for hypertufa pots- and we made a project late winter to clean out the rot much as we could until we were mostly at just the bark shell and then we lined the shell with draped hypertufa material , bottomless, and than stained the concrete to make it blend in a bit better with the bark. And yes, I do have a thing about hostas. Haven't seen a doctor about it yet but it looks as if there's no cure other than another hosta....
I'm still thinking slime mold. That should wither quickly though I think and would already be gone. Looking at the image of the stone, note that the little fruiting bodies seem to be coming out of what looks like a vein of iron. I don't think it resembles the sedum stem rot. One of the little fruiting bodies has opened like a tiny flower. Very interesting growth anyway.
So the bottom line is that the original poster should remove and clean that infected pot? Or .... And the decorative stones ? Cautiously re-use plants that appear ok? Or not Reuse the hypertufa (it is somewhat porous?) Just curious what NEXT steps are.
The hypertufa is non-removable, it's intended to stabilize the bark structure, so that's a no-go. The 1/4" crush is and was easily replaced, the plants were disposed of expediciously. And you're right Eric, I had trouble as well reconciling the suggested sedum stem rot with what I was experiencing. I'm attempting to contact the author of the Illinois EDU article linked to above to see if she'd be able to help, but no response thus far, at least the email hasn't bounced so that's encouraging..
Hi @Pieter - The fruiting bodies on the gravel appear to be myxomycete (slime mold not fungus). They are too small for Stemonitis, something like Stemonitopsis perhaps ... in-person expert examination required with good microscopy and a good key. The ones on the Sedum I can't see closely enough to be sure, but could be the same: With magnification, check the base of the stipes to see if these are growing from or growing on, to exclude something fungal distorting the sedum leaf structure. Myxos are harmless to your plants, soil etc.
Frog, thanks for piping up. I have little doubt the infestation is the same on the Sedum as it is on the crushed gravel. While I appreciated the effort on Houzz and the link to the Colletotrichum page it became clear quickly that it was the wrong direction. While I don't really care to identify the particular specie involved, a quick Wikipedia check shows that indeed some form of slime mold is the underlying cause. Good to know it's harmless to the plants but it does make me wonder how it got there in the first place, will never know I suppose.
And in many cases until you're looking for them, based on what I'm seeing posted by two people in particular on Instagram. They're often so tiny.
I find them in the Garden occasionally. They are often gone within the day, but sometimes they linger.
I thought the succulents in question had been tossed but it looks as if they weren't so my wife thought we should try to hydrate them and plant them. Into a shallow saucer they went yesterday afternoon and I couldn't believe my eyes when I saw them this morning: the slime mold really appreciated it and showed that by re-fruiting...Camera on tripod, get my old Zeiss Planar on an extension ring for a close-up and here we are!
