Romneyas CAN be grown from seed though I think it's rather difficult....some say you need to seed the flat and then set the top layer on fire to get them to germinate.....I do know one person, Amy Winslow, I've lost track of her now, she had Moonrise Nursery in Thousand Oaks and she said she was having success from seed grown without resorting to fire....generally, roots are dug in Nov-Dec for propagating. Some of the garden club members in Fb were digging the just before their garden club sale (another time of year, I believe Spring) and said they had success....but I don't know if anyone followed up on that with the buyers to make sure the plants lived.