as I have heard horror stories about the ROS re-seeding itself all over yards & flower beds etc
I have a bunch of ROS all over my grandmothers yard...
and OH BOY, do they reseed themselves!
I've been plucking and weeding sprouts all spring
/summer from my veggie garden, and all the area around it... they have a deep root system, so if you don't get them quick, thye will be a bit of a challenge to get out..
I've resorted to, on the ones nearest my veggies, to just clipping the flowers
off, so they can't dry up and go to seed
I'm not sure about the doubles though, because I'm not sure what I have..
Good luck with them!