Meconopsis, seed very easily but if you dig down deep enough and get enough root system then it will take, it will possibly sulk a little but water well and they will perk up, Echoltzia the californian poppy can be a little more temperamental, the Papaver poppys, will respond too but may sulk and if the stems are about to burst into bloom then they may not flower but the foliage will pick up after plenty of watering, the best time to do divisions of these is at the back end, you can also propagate these by root cuttings, chop pencil thin roots into small sections and pot them up, very easy, julien.

Regarding the Meconopsis these are tap rooted you dig them up to divide and it is bye bye plant! Best way is to grow from seed. Trying to get rid of Mec. cambrica is a joke - you miss one little bit of root and it regrows!