Thank you for all the excellent thoughts all, and sorry to disappear; I didn't realize the thread had grown so! The insufficient sun query is an interesting thought; up until a month ago, we had a MONSTROUS tree in the yard (which is very small) which certainly affected the sun in the garden area. We had it removed after it threw two giant limbs at our house in a one month span. It hasn't really been long enough to see what sort of an impact that will have and the black spot was already well established at that point, but I hadn't thought of that. I do like the idea of replacing a couple of the more damaged plants with modern varieties and seeing how they fare next year. Combined with the added sun, I'm sort of excited to see what sort of a difference it makes. In the last week, most of the plants have shot forth new flowers, which was pretty unexpected- they went from bare to bud to flower seemingly overnight. The humidity has been MUCH lower and the whole garden seems to be breathing a sigh of relief. I may see if I can get some pictures before the flowers fade. Thank you for all the guidance. I'll keep checking in and I'm sure I'll be back with more questions!

Nope. They're something else.

I already answered another post of yours, and it sounds like you might have already replaced the soil. (You can read my comments in that other post) Anyway, two things stand out in these pics: (1) no mulch (2) other stuff in the containers (lemon peels??) If you have pictures of the fungus that is now on the foliage, that might be helpful in diagnosing the specific problems you're now having.

I have had an excellent outcome, rather unexpectedly, regarding toenail fungus. I have a farm and often have to wear rubber boots. That's when the problem started. I, too, tried everything. Then I got leather boots and thick cotton socks, and within 6 months it's almost gone. My feet sweat, there's no getting around it, but they were in rubber or plastic, nonbreathable shoes. They are in a natural, breathable shoe now, and it's very different. The boots are extremely comfortable. And good shoemakerrs will tell you, never wear a pair of shoes two days in a row, so they can dry out. It makes all the difference. I think it's the vinyl, rubber, plastic shoes, along with synthetic socks, including women's nylons that are causing the problem for most people. Our feet can't breathe. The trick about getting leather boots, shoes and sandals to fit you correctly is to wear them, and get them wet, then keep wearing them for a couple of house. It's not too hard to do if you are hiking or working outside. I know, it might seem freaky, but they conform to your foot exactly as they should if they dry on your foot. I do it with every pair of leather shoes and they always becomes my favorites.