You don't say where you live, but since it's getting colder where I am and you just transplanted them, I would suggest you wait until early spring before you prune them.* Give them time to let their roots establish.* I would suggest you prune them by one third to one half and remove all the flower buds the first year to help them get established.* You should find this helpful.* At this first site you can click on the plant sketch at the bottom and keep clicking on the plant in the pop up box to see how to prune.
When weeding, the best way to make sure you are removing a weed and not a valuable plant is to pull on it. If it comes out of the ground easily, it is a valuable plant.