I did a double petal row, I originally tried it with a single but ended up doing a double instead. I really like the way it turned out, once I'm done with my sister's quilt, it'll get finished. I'm considering a black backing and then doing a stipple in a gold metallic or maybe a pale yellow, I hadn't gotten that far yet. I'm calling mine 'Midnight in Grandma's Flowers', the gold metallic, I think, would look like fireflies flittering around the flowers.

I can also tell you that for the flowers themselves, I used fat quarters, and the size of my quilt, it was three fat quarters per color with still a lot of hexies left over if I decide to expand the size of the quilt, so three-quarters of a yard for each color. If you're doing a single row of flowers, then at the very least, I think three yards would work for you very well, that way if you decide to go with a bed size, you should have enough to get it done and maybe enough for the binding as well.

I loved doing my flower garden, I machine pieced mine so I could get over my 'Y' seam phobia. Not afraid of them anymore, lol.