I have a clematis (paniculata) that i planted last summer here in Chicago, Illinois. it did very well, growing about 8 feet on a trellis and porch. Not many flowers but that was to be expected. I've been poking around in the garden and noticed that this same clematis - which is budding up nicely - has what looks like hard water deposits in a few places on the main stem. It's a white powder, looks sort of granulated, like flour that's gotten wet. It appears on the second segment of the main stem, and then again about a foot above ground where the first major branching of the plant occurs. I'm confident this is not stem rot or wilt. The plant appears to be healthy right now. Does anyone know what this could be? Any help - much appreciated!
Hi Tina, You are already aware that clematis are prone to many fungal problems, some of which cause wilt. I have discovered in my search for your answer the that the fall bloomers, such as your C. paniculata, tend to fight these off. There are four fungal infections that do appear to infect them though. Aecidium otagense is a rust that can actually be parasitized by another named Tubercutina persicina that sounds like what you may have. The Tubercutina persicina "gives the swollen stem areas a violet powdery appearance". Unfortunately I can't find a picture of it. There are others listed here as well. This site states that you need do nothing, but I think I would prune off those areas, dipping my shears in a bleach solution between and after the cuts. http://www.forestresearch.co.nz/PDF/Path_14_Native_rusts.pdf Newt
Use Lysol instead of bleach. http://www.puyallup.wsu.edu/~Linda Chalker-Scott/Horticultural Myths_files/Myths/Pruning tools.pdf
Thanks for this info. The thing is, the powdery stuff looks off-white, not necessarily violet/purplish. It really looks a lot like hard-water deposits. But none of the other plants in this area of my yard have this problem so I've ruled out hard-water deposits. I am on the fence about cutting this plant all the way down to the ground -- the powder appears just above the ground. There is a new bud at the bottom of the plant, just below the affected area, which is encouraging. The rest of the plant is doing quite well, lots of new growth all over starting at about a foot above the affected area. I'm going to sit on this info for another day and make a decision tomorrow. I guess if I'm going to cut it all of the way down to the ground, now is the time to do it. We are having an incredible spring here in Chicago, Illinois. My only hesitation is that a cut that is this dramatic - the plant is about 5 feet tall - might kill it? End of rambling. Thanks so much for all of your insights!
If it's just budding out this type of clematis is one that you might cut down in spring, at least occasionally, to control its size and keep it green to near the bottom anyway. Otherwise, if its growth doesn't seem to be adversely affected by the Deposit of Mystery: If Ain't Broke, Don't Fix It. If it blights off later then you will have a definite hint there was a problem.
