Dieback is common on many plants until they are fully established. My Heptacodium is several years old and still gets a little dieback of thinner twigs.

Like laceyvail, my heptacodium (planted fall '03) often shows some very minor small twig dieback in the spring, but I haven't observed any significant damage from low winter temps (-15 F in Jan '09 didn't seem to bother it). There are reports of a canker/dieback disease that sometimes does serious damage. Mine has had a few minor cankers over the years that I've had to prune out.

So fairly normal...seemed fine, I was just curious as I was hoping I didn't plant it in an area with too much wind.

What are the signs of canker? Is it similar to the discoloration of cherry canker?

I have my 12' Heptacodium planted in full sun and full exposure. I too was worried the first year or two about the winds, we get some really good ones here. In fact lots this week, gusts up to 60mph. It has never missed a beat. Grows fast and strong and I love it. Ditto on the very MINOR twig dieback in winter.

"What are the signs of canker? Is it similar to the discoloration of cherry canker?"

Not sure what kind of cherry canker you're referring to, but the cankers I've observed on my Heptacodium were mainly on smaller branches. They were sunken, darkened areas that were (initially) more or less spindle-shaped, but would (if not pruned out) gradually expand until the branch was effectively girdled. I'm not too concerned about some occasional cankers at this point - overall my plant is quite vigorous.

In addition to the interesting bark and late season red calyces, I really like the fact that it is highly attractive to pollinators. I also observed a few hummingbirds at the flowers last year.

I've had a disease-free Heptacodium for about 6 years, but started getting canker 2 summers ago, loosing a significant size trunk, and branches. I attribute it to too much water. We've had more rain, and it's planted near a down spout.