I would hope that someone pointed out the the growers the conditions necessary for the Southern Blight fungus, Sclerotium rolfsii, to survive. That is damp, acidic soil at temperatures above 85°F. Not the ideal cultural conditions for growing Helleborus, which prefer a drier, but moist, alkaline soil. The fungus will not survive in alkaline soil. Can be eliminated by soil sterilization, so they probably aren't using a sterilized soil mix. Can also be spread by contaminated tools. When present, the fungal growth is exacerbated by the use of high Nitrogen fertilizer, which I'm sure the growers use to accelerate the growth of their plants. I also would avoid purchasing from those growers and advise closely inspecting any plants purchased for a gray mold like substance around the stems at the soil level and soft tissue in the stems at the same level. I have grown Helleborus for more than 20 years and presently have hundreds of them. Not once have I experienced a problem with Southern Blight and don't know of anyone else, including nearby growers, that have either. Rb

My experience with southern blight is not extensive, but I have lost one hosta to it in 2012, a big fine The Razor's Edge. It was fine one day, and the next it was flat to the ground. It died. Then in 2013 I was quite careful of it, but late in the year I found Totally Twisted coming down with it--I'd learned the signs--so I treated it with an ammonia/water solution and repotted it totally. In 2014 I did not catch Totally Twisted in time, but decided to see what would happen. There was total devastation of the plant itself, but in the middle of it was ONE EYE that was not affected. So with that new eye I hope TT comes back resistant to southern blight. I'll let you know next year. The one eyed Totally Twisted is now dormant. My presumption with southern blight is that it shows up when it is very humid and the air circulation is poor. I hope you can remember if the plants in your garden stricken by SB were in areas pretty much enclosed where no breath of fresh air can circulate? Plus, SB affects many other species of plants. My DH had some issues with peppers this season. He dug them out with a large section of the raised bed. I asked him what he did for them. He said he cried! hehehehe He explained that he lost the first two peppers. But then he found a way to deal with the blight. I had bought some of the recommended chemical for treating SB, forget what it is now. Well, he looked at the label for ingredients (he has 1 degree in organic chemistry) saw the active ingredient was the same as in hydrogen peroxide available at the drug store...a whole lot cheaper.....which is in a 5 % solution to begin with. What he did was dilute that in a container with plain water to have the total H peroxide used from the bottle to be 5-10% of the mixture. I kept seeing empty brown peroxide bottles in the garden, and wondered. He dosed the roots of the affected plants until they started looking better, which took about 3 to 5 days. He lost only the first two peppers, saved the rest. So, it is worth a try if the need arises. It could happen to any other plant which falls dead (or nearly so) and you can test this remedy for yourself. Nothing poisonous about it. Am I making myself clear about mixing it? The original hydrogen peroxide is only a 5% solution. If you used the whole bottle, you'd need to mix 10 bottles (same size) of plain water to spray your plants. That's the simple form of math that I can remember. One to ten.

bk....I have had an issue with my Undulate Albomarginata over the last year that looks related to southern blight. Last summer the leaves started dying off much like yours in the picture you posted and went from nice and full to about 1/2 gone by fall. This year it came back weaker and I am now getting leaf die off again. No leaf curl or anything like that. It's just one or two at a time and a slow process. Yesterday I pulled it all out of the pot. The media was still very damp from our last rain less than a week ago. There are some of the orange balls in the media but not a huge amount. I washed off the roots, they all look healthy, firm and white with no odor, but not as full or long as what they probably should be for a three plus year old plant. It was one of my first hosta and I definitely potted it way too large. I repotted it all in two smaller pots and will see what happens. The black spots are just something that fell on the leaves.

Yep. That's southern blight. Do NOT till the bed until you have removed the soil from around the area and thrown it away. Replace with fresh soil. Make sure to disinfect all tools used in a way that prevents potential spread of the organism. I worked in a lot of organic matter this spring and drenched with B. amyloliquifaciens and B. subtilis and use a lot of coffee grounds (which supposedly are a food source that various Trichodermas like) in the bed where I had it last year. So far, so good. Luckily for me, and, it seems, for you, southern blight doesn't strike until very late, but the down side of that is that I won't know for sure that my efforts have been successful until the end of the season. If they're not, I will try grafting with Maxifort next year. One thing that my efforts seems to have helped is that the bed where I had bacterial wilt problems last year doesn't seem to have those problems this year. Of course, it could also be that what I'm growing there is a variety less prone to the disease. But that's encouraging for me, as it's very hard to find a rootstock that resists both bacterial wilt and southern blight.