I suspect that your lobelias rotted as a result of winter mulch, not disease. Lobelias need a light and airy mulch, such as pine straw, for winter. What did you use for winter mulch? If it was a sogginess problem, then there was no disease involved, and hostas should be fine there.

Well that's a relief!
The mulch was shredded pine bark, but there was also some leaves that had gathered in that area over winter. Plus we had alot of snow followed by some heavy rains lately and the ground everywhere is saturated.
Even though this area is usually a bit on the dry side since it's on a slight slope, it got it's share of moisture this past season.

Whenever it quits raining, I'm going back out and have another look and if possible get a picture of what is left of the last plant. I want to be sure, but I'm keeping my fingers crossed that is was just a moisture problem.

Thanks for the reply!

Janet

the exact same thing is happening with my cardinal flowers ... actually they LOOK wonderful, all green & perky .. however, when i attempted to move some of the shredded leaves that they were mulched with .. horror of horrors .. they weren't attached to the soil!!! so sad