E. capilifolium and E. compositifolium are similar, and fairly linear in the early summer months. Lateral branches usually start spreading here in late July, and they typically flower in September or October. I loaded a photo of one of our E. capilifolium plants taken July 25th, still in its linear form, for comparison. I thought that your plant could be E. compositifolium, because the leaf segments seem relatively wide. That species has ultimate leaf segments 0.040 to 0.080 inch wide. E. capilifolium has more narrow leaf segments, ranging 0.008 to 0.012 inch wide.

Do they bloom with a yellow head? Sorta look like goldenrod.

I think that sounds like a really good idea. I can empathize. My area is not as large as yours, but I have several bedding areas that I've felt so defeated by because of the weeds. These are gardens I inherited, and though i enjoy a certain amount of it, it's just too much to keep up with. I have come to the same conclusion that I need more shade and have begun planting more dense, low-maintenance shrubs in among the perennials. They won't get big enough to shade my established sun perennials,(or my neighbors) but will shade the weedy areas in between and reduce them, hopefully. The flowers aren't enough competition for the weeds that spread from my neighbor's yard and I want more variety of plant types. Good luck!

Ok dahlia yes I think so The large one lying flat is different I'll try to get a better photo tomorrow. For the person who thinks I don't know what a weed is: telling someone that a weed is something growing where they don't want it is 1) condescending 2) annoying 3) useless I know some of you are regulars but my advice is don't condescend.