As a comment about
Tree Dahlia (Dahlia imperialis),
zuzu wrote:
This plant is not a good choice for most gardens. In my garden, for instance, it grows to about 20-25 feet tall each year, but it's usually snapped in half by the first strong winter wind. Another drawback is that it doesn't bloom until late November here in zone 9, but it succumbs to frost within a few weeks, so the enjoyment factor is quite fleeting when it comes to the blooms.