Hi Andy,
I'm no expert, but if the plants seem to be doing well in the pots, I would leave them there and go out and get a new variety and plant that in the garden. If you really want to move the plant you already have, I wouldn't recommend doing so until October time (I gather they are hardy as they are in pots) and replant immediately and plenty of watering to minimise the stress of the transplant.
I hope this helps
Sharon