What about a blue one such as Mayflower, Spinners, Brookside or Rozanne? or a white one such as sylvaticum album or sanguineum album? Do you want it to bloom before, with or after the poppy blooms? That's something to think about. How tall do you want the geranium to be? Is the geranium going to be planted beside or in front of the poppy?

ontnative,

i would like them to bloom simultaneously,

thanx,

j.

G. sylvaticum 'Mayflower' and 'Amy Doncaster'(both blue) G. sylvaticum album (white) and G.'Spinners' (blue) all bloom in May-June here. Brookside and Rozanne may start a bit later. I don't remember their exact blooming periods.

Here is a link that might be useful: Geranium sylvaticum Mayflower & Amy Doncaster