I don't know the name, just wanted to add my picture. I brought some home last week, to try and identify, too. Also growing in a wet ditch. I'd never seen any this big before either. There were a bunch of them growing together. It really was striking. A beautiful plant. You mention it looking like goldenrod from a distance. The heads though dry now and falling apart, are still a beautiful golden brown color.

My Mom LOVES baby's breath, so I wanted to plant some for her (perennial), but her soil is way too clay. I found a great Achillea that looks very much like baby's breath. It's Achillea ptarmica which comes in a regular size of 2 feet: 'Angel's Breath'. And, it also comes in a smaller size at 1 foot: A. p. 'Ballerina'. I've had great luck with both. So, if your soil doesn't drain well enough for baby's breath, you may want to try these. Also, they look great together. They can be a little assertive in my garden, but never aggressive. Happy gardening!

it is called dollarweed, and like ground ivy it can take over. i will just try to keep it under control. why is it if i like it as a ground cover it takes over?

I just looked up Oxalis stricta and chickweed, and I think you are might be right about both. Is it crazy that I think the chickweed doesn't actually look too terrible as a ground cover in my garden bed?