Coreopsis might be another possibility. Close-up definitely needed! If you are just trying to copy what somebody else grew (ie the photo isn't of your plants), just pick something easy and yellow that you like. Marigolds are a nice, easy choice. Nasturtium is another. I personally would choose calendula. FataMorgana

Agastache �Blue Fortune� ? Here is a link that might be useful: Agastache �Blue Fortune�

The small flowered yellow 9/1 TBD is a Goldenrod, Solidago spp, but you need to see more of the plant for a better ID. The small flowered white 9/1 TBD might be Polygonum scandens, but I wouldn't swear to that. 8/4 TBD is Burdock, probably Arctium minus. Nice pictures. My mother grew up in Somerset, are you anywhere near there? WW

I have several Prunus serotina, including one large tree that is approx. 50 years old. The big tree makes zillions of seedlings in my back gardens so it a likely culprit for mkaing your seedling. It is a wonderful tree for wildlife but grows fairly large with a somewhat rangey habit. The bark becomes dark and scraggy looking in old age. I would plant in a naturalized area. #4 looks like my Aster cordifolius (aka Symphyotrichum cordifolium). I've got lots of it - also a prolific self-sower. What a gorgeous haze of tiny lavender flowers in early fall, esp in mass.