It grows very well here on the Central Coast of California, zone 9. As Chad observed, only extreme cold stops it. There are plants in gardens here that are easily 16' tall. Randy On Thu, Dec 1, 2011 at 3:30 PM, Chad Schroter <Chad.Schroter@sandisk.com>wrote: > Unlike other dahlia's I grow D. imperialis does not appear to go dormant > with respect to day length, -- * * A long habit of not thinking a thing wrong gives it a superficial appearance of being right. - Thomas Paine --- * *