I did in the summer as my sister said, and does....she cuts a good chunk of Mum off and removes the blooms and just sticks it in the dirt
and gets a new plant, the one I did this with in August is alive and well. At the time I only did the one because only recently did I decide that
in spring I will be needing about 5 more Mums to plant all along the embankment that is up above our driveway. So I thought why buy if I
can harvest from what I have, I know it may take a few years for them to bush out and be bloomed, but I am patient and love a experiment.