As both treatment and preventative measure, I sprayed the leaves of the beleaguered plants with a milk/water solution that the other gardeners have had a lot of luck with. This actually seemed to work almost immediately, so hopefully the bits and pieces left of zucchini and squash plants will revive enough to give me a few more edibles before it gets too cold.
I forgot to photograph my only surviving pumpkin of meaningful size - the two that had made it to fist-size before I went on vacation succumbed to rot while I was gone, despite
And I forgot to check the garlic. Damn. Need to do that very soon, I think, since their leaves have by now been entirely shaded to death by the rhubarb and pumpkin leaves.

Speaking of the rhubarb, its time finally came, and I pulled it all up tonight. I put about six armfuls of various gigantic rhubarb and squash leaves into the compost tonight - the worms should be very happy. I also pulled up most of the beets, which are of substantial size, I think; most about the size of my fist, which I admit isn't very big, but isn't bad for vegetables I planted out of boredom and largely ignored all summer.
I feel much better and less neglectful, though there's still some dead flowers and a lot of weeding I didn't get done tonight, and I need to transplant my indoor tomato seedlings to bigger pots (I only have pots for about half of them - have to figure out where I'm going to get more!), and I need to find someplace indoors for the big healthy ones currently fruiting on the balcony. But there's always next weekend, I guess.