dbags, For sure I would prefer having cg to qg. One of my local nursery/lawn products guys tells me all the time not to worry about cg, as it is far easier to get a handle on than a host of other weeds. You may also want to check into the possibility of orchardgrass. I am beginning to think I may have misidentified some of my own grassy weeds. Not sure it makes a whole lot of difference, as selective chemical treatments are largely unavailable for a good many grassy weeds (such as orchardgrass and quackgrass). I believe orchardgrass is a bunch grass and can be dug out and replaced (no rhizomes). The problem w/qg is that it spreads via rhizomes and physical removal is not especially effective. I have not gone the RU route on my whole lawn either, but I have spot treated a few 2' X 2' areas of heavy qg infestation and reseeded (with modest results).

Garlic mustard. Invasive weed. FataMorgana Here is a link that might be useful: Garlic Mustard

Looking at photos such as: ...it seems different from Eupatorium capillifolium. The stems on my plant are smooth, with no hair, and the "leaf" sections are thinner, almost tubular, with less of an orderly fern-like structure to each leaf section (sorry I don't know the proper terms to use). Here's more of a close-up:

Jewelweed. A native impatince. has a yellow or orangish cone shaped flower sometimes with a cup handle like structure attached. A very nice plant.