Posted: 24/08/2016 at 23:47
Lie, too soon to divide them. less than a year planted.
You will need patience and wait at least a couple more years before you divide them. If happy they will sucker though....careful many have come to regret planting them as they can be invasive.
I suggest you wait, see if you like them and if they grow well there, even too well, then decide if you want more