A wild elderberry tree (NOT a cultivar) easily grows to 15 feet in one
year. Then it slows down a lot, unless you decide to cut it down, in which
case it grows right back just as fast. Start with a three-footer or
five-footer in a 5 gallon container from a native plants specialist, just
so you know you have a well-developed root to start with. The trunks &
bigger branches are hollow but extremely hard even so, with lots of give
in a high wind, though if they ever did break off in the wind, it springs
back up the next year good as new. Other such fast-growers are far more
likely to snap off in the wind, & far less likely to grow right back.

-paghat the ratgirl

--
"Of what are you afraid, my child?" inquired the kindly teacher.
"Oh, sir! The flowers, they are wild," replied the timid creature.
-from Peter Newell's "Wild Flowers"
See the Garden of Paghat the Ratgirl: http://www.paghat.com/