catalpas are notoriously brittle-branched in youth - they grow very very
fast in most climates and are susceptible to breakage in wind or rain storms
and in ice storms or heavy wet snow in winter. However, in spite of this,
they are one of the more long-lived healthy trees from the list of fast
growers (unlike things like poplars and silver maples). At least that is the
case where I live, in the inland northwest (zone 5/6) I would say that you
would probably like to get the central trunk quite strong - the tree has a
tendency to be reluctant to get a strong leader going. I wouldn't prune side
branches the first few years, until you can begin to see the main trunk
getting very "secure" on its way - then begin selective pruning to get the
shape that you want and to decide where you want the lowest branches to be.
I planted one at my old house as a street tree in 1997 or 1998 as a 5-6 foot
nursery tree - now it is about 20-25 feet tall - and that is after the
central leader snapped in a strong windstorm when the tree was only 2 years
I grew this Northern Catalpa from a cutting about 4 years ago. This
spring the top 7- 8 inches (last years growth) see the picture, started
to bud out but died. There were plenty of shoots below that and I let
the top one grow. It has now grown 4 feet from that point.
The trunk is ¾" thick below the new shoot and above. I'm afraid
now that it has grown too fast (soft) and might now survive an Eastern
Last year I removed all but 3 levels of leaves as it grew (there are
always 3 at each level). I'm not doing that this year because I have
the feeling that the top did not survive because I forced it. Does
anybody have any experience with this tree?