Do you mean Brugmansia? the flowers hang down and Daturas point down.

I have nine different brugmansias and overwinter them
in a greenhouse with just a tiny frost protecting heater,
I find the drier you keep them the better...they die from rot more than anything else.

Other than that a spare bedroom or garage (they don't need light if you keep them dry and dormant).

Mary.

I grow Datura (the flowers pointing up one) as an annual - I have over wintered them in the garage as Marybush described, but find that newly grown plants perform far better.
If it is Datura, then sow the seeds mid January in a bright spot, potting on just the once into three inch pots. Mine will be planted out mid to late May at which point they'll grow rapidly, usually coming into bloom early July. Allow the third or forth flower to form a seed pod for next year, which should start to split at the end of September. Collect the seeds and clean and dry them before storing until January.

Thanks to both of you. Mary the description of your Brugmansias sounds like mine! I will invest in a heater but do you cut them back when they finish flowering?
Dolores