Having finally identified the enormous mystery plants in my corner bed, it was time for them to meet their fate. Late Sunday afternoon I started ripping them out. It turns out there were close to ten of the things growing in the little nightshade jungle I had going there. I intended to take out all of them, but when I came to the last (and largest) one I stood back and considered it for a while. With some open space around it I could see that it had developed a fairly thick, short trunk that branched out rather gracefully. If I yanked it the corner was going to be really bare. In the end, I gave it a reprieve.
While I was at it, I ended up ripping out the nasturtiums too. I do this a lot with nasturtiums and I've come think of it as normal. I like nasturtiums but I find that just at the time they fill out and bloom heavily, they also manage to look scraggily at the same time. I started out just cutting them back, but I got a little carried away and they all found their way into the green recycling bin. There were many seeds left behind so I know they'll come back and that's fine with me.
Today I completed the clean-up. The bed is now completely weeded for the first time this year. And Linus the cat, who has lost his little jungle hang-out, is not happy. This is what the bed looks like now:

What's left there now are (from left to right): an amaryllis, a calla, three primroses, the nightshade shrub/tree, a wild geranium, a cigar plant (Cuphea ignea), a lilac (which will be moved to a sunnier spot in the winter), a Phygelius macrophylla, and some lobelia that has sprung up at the base of a rose. Obviously, I need some taller plants in the back, so I bought some amaranth seeds (Love Lies Bleeding) to plant there and I'm going to try some pole beans up along the fence. I plan to transplant a couple of nicotiana and some dianthus that I have in pots into the middle part of the bed. But I'm getting ahead of myself--that's Part Two of the makeover.