The message
from (Nick Maclaren) contains these words:


One of my books says that this needs pruning when young to avoid
becoming lank, and its growth (from the tips) confirms that. But
when, and how harshly?


Regards,
Nick Maclaren.


The website, http://www.ag.auburn.edu/hort/landscape/338.html, has for
Koelreteria paniculata:

GROWTH HABIT: Grows 15' to 30' tall. Can be single or multi-trunked
(severe renewal prune when young).
This is unhelpfully vague but does suggest that harsh is OK.

I have a specimen which I bought cheap which has a very long bare trunk
and then a small but quite dense head of short branches which are still,
after four years, putting on only a small amount of growth. It's lanky
in the sense of being all thin trunk and not much else. Is that the kind
of lanky implied by your book, do you think?

I think mine had been in a pot for too long but it is at least holding
its own and I'm still hoping that it might just take off one day.

Janet G