Depending on how cold it will loose its leaves in the winter when it freezes it will have to be cut back ... I generally cut it back to the ground if it is a hard freeze ... No mater what you will need to cut it back once a year it can grow 20ft tall in a season.. Keeping it kinda bush like helps so you can pick the leaves. Its in flower now in another month or 2 it will put out seed pods.
I have 2 types one which gets tall and I am trying another one that claims it stays shorter I have seeds from the shorter one , they are big size of acorns and germinate readily.
Seeds are cheap on ebay or send me a pm I have a few to share for trade or postage
