Propagating mint from root cuttings

I know that's how Jekkas propagate their mints... if I could get a load from a couple of plants it would help my lack of greenery hugely

That link says next month? I don't think now would hurt too much would it. I'm going to take the plunge ... I have don't it with Phlox, but put those straight back
In the garden. Wish me luck.