i think you'll need to overwinter them for standards. as the woody trunk develops towards the end of the season - and you'll need it to support the big mass of leaves up top. or else start them very early indoors. it would be a shame to let it go in the fall in either case. so sun-room/greenhouse would be very handy.
i have overwintered coleus - but you need to be very vigilant about pests: scale could be a big problem.
