Shubert chokecherry leaning in top trunk
We have a 2-year-old Shubert chokecherry tree. It's done very well, with one minor exception: In its upper main stem, it leans slightly to the west. For the first two years, we let it go in the hope that it would right itself. We also pruned back some smaller branches to encourage more growth on the east side. However, it's still leaning (though most of the trunk, up through the bottom branches, is nicely vertical).
This tendency to lean seems to be occurring mainly because the branches of Schubert chokecherries are a bit droopy, so the upper stem isn't strong enough yet to support its own weight.
So we decided to run a small dowel rod up the top part, starting at where it's straight and then loosely attaching it with twine in three places, to coax it to grow upward (the twine is tight enough to hold the dowel rod in place, but not tightly wrapped around the trunk). We also pruned off a branch at the top that appeared to be a pretty major split.
That's all I can think of to do. How long should we leave the dowel rod in? I'm thinking one year. I know I also need to be checking periodically to make sure that the twine isn't rubbing into the bark. Any other recommendations? Thanks!