hardiness of dahlia imperialis?

[pontus]

Hello everyone,

2 days ago I tried digging up my largest dahlia imperialis for winter storage, but the tuber had expanded so much in all directions that it was very hard to dig up, at least without damaging it considerably,

so I was wondering in case I leave it in the ground with a very heavy mulch of soil, needles, branches...etc as well as a rain cover, will it be ok in the ground over winter?

Pontus

[johnstephen29]

Hi Pontus it's risky in cold climates, could you take some cuttings just in case it doesn't make it?

[Diane Whitehead]

The only place I've seen it growing and flowering outside is in California.

I have had one in my unheated greenhouse for about four years.  It hasn't flowered yet, but I live in hope.