I've grown a potted Yellow Elder from a seedling...bringing it indoors for either 2 or 3 winters now...forming it into a tree shape by cutting it back over-and-over. It's gotten huge this year. I've heard this might live in my zone (7b/8a) outdoors, only dying back to the ground over winter. Can anyone confirm or clarify? It blooms like crazy, and is quite fragrant. I'd like to keep it...but it's outgrowing my resolve.