Helleborus niger leaf spots

I have been waiting for my hellebore to bloom and noticed yesterday that the leaves have white spots. I hope that this isn't some dreaded terminal disease. The plant is four years old and has never had this problem. Any suggestions?

My first thought was cat or dog urine, but I see the same spots on a dry leaf in the mulch. Is there any texture to the spots or is it just bleached?

Thanks for the reply. I have a wood privacy fence so there no dogs in the yard but there are cats in the neighborhood. There is no texture to the spots they are smooth, appear to be bleached, and continue to the underside of the leaf. There were a few other oak leaves near the plants that also had spots. I cleared most of them away except the one in the photo. I'm beginning to think, as you have, that it is something external to the plant and not necessarily a plant disease. I am patiently awaiting blooms and hoping that whatever it is will not kill the plant.

This shouts fungal leaf spot to me. I don't think the oak leaf has anything to do with it.

From http://plant-disease.ippc.orst.edu/factsheet.cfm?RecordID=1047&rec_type=image
Hellebores, like roses, can suffer from a type of black spot that is at best unsightly and at worst fatal. Drenching the whole plant with a systemic fungicide once a month should help to prevent this. Remove the worst-affected leaves.

Another site: Black spot causes large, irregular, black spots on both
sides of the leaves. The spots have concentric zonations
and often run together. Many leaves yellow and die
prematurely. In spring there may be black, canker-like
spots on the leaves, stems and flower stalks. The stems
shrivel at the point of infection and fall over. The
leaves and unopened flower buds wilt. The flowers may
also have black spots. Remove infected leaves and
flowers. The causal organism is Coniothyrium hellebori
and there is no chemical control.

But I found that drenching with copper fungicides can be a way to control this disease.http://www.copper.org/applications/compounds/table_b.html

I would take off all of the infected leaves and then drench. Kocide is a copper based fungicide...

I have been investigating this spot problem and found that many other of my plants have the white spots. I have found the spots on Japanese cleyera, pieris, roses, pachysandra, photinia hedge, Stokes aster and many other plants. I have operated my automatic sprinkler system several times in the last few weeks for the first time since last summer. It seems to me that the chlorine amount in the municipal water supply has been increased and that these are bleach spots. The areas on my cedar privacy fence that recieve the water spray have also turned white. I have operated the sprinklers for many years and have never noticed this problem ocurring.

Well, if you are seeing this exact same thing on all of those plants, it would seem that one could rule out fungal leaf spots, since most fungi are plant specific, including the one for Helleborus niger.

ceejay
I am going to try and determine whether the chlorine content of our water supply has been increased to confirm that may it be the cause of the problem.
I appreciate your info on the hellebore fungal problem and the copper based fungicide treatment.

Here is a leaf blight of pachysandra, along with a photo showing winter damage for comparison. http://counties.cce.cornell.edu/suffolk/HortFactSheets/factsheets/Leaf%20Blight%20of%20Pachysandra.pdf

Photinias and cleyeras are both prone to Entomosporium - another fungal leaf spot. http://entoplp.okstate.edu/ddd/diseases/entomosporium.htm

And of course, roses are prone to black spot. http://www.oznet.k-state.edu/path-ext/factSheets/Rose/Blackspot%20on%20Rose.asp

Just trying to make sure that all bases are covered...

I'm a little surprised that you have leaves on so many plants, since I thought Tulsa had been hit hard this winter. Maybe its all freeze damage...

I hope that there is a simple solution.

Thanks for the links, I will check them out. All of the plants that I mentioned still have very green leaves with the exception of the roses. Some of the rose leaves are green but not all. Our winter here hasn't been bad at all, the temperature Thursday was seventy one degrees. We had a light dusting of snow a week ago but it has been a mild winter compared to the winter of '08.
Thanks for the information that you have offered.
I'm still waiting for the helebores to bloom.

You're very welcome. I guess all that cold weather didn't extend down to you. My mistake.