Might the compact plant in this very first photo be Alyssum Compacta (Basket of Gold)?

1. Could be Alysum saxatile. 2 and 3 are one of the Chenopodiums. Looks like C. album. 4. Is an Amaranth. Last one is obviously a grass but without flowers hard to say which. If you feed birds there it might millet.

I think all of them are weeds, except the first pic, and I'm not sure what it is. I don't know the botanical names, but pics 2 and 3 are Lamb's Quarters. I'm not absolutely sure about #4, but it closely resembles a weed I'm familiar with.

Lambs Quarters is Chenopodium album.

Thanks everyone. I do indeed put out bird seed (as Floral_UK asked), and do often notice the millet germinating, but then I usually pull it up while it's still a tiny seedling. I guess these larger grasses are therefore some millet seedlings that I never got to pull up. I didn't realize how large they could become...

#4 is an Amaranth, maybe Amaranthus retroflexus. Pigweed. Seedy and weedy.