I have purchased several big and beautiful ming aralia plants from Jim Smith Bonsai in Vero Beach, FL. [btw, if you've never heard of Jim's, check it out] Put the plants in bonsai pots mid-summer 2012, one in a 10" pot, about 2' high with trunk about 2.5" and 3 others in a 12" pot grouping, about the same size plants. They did great until I put them in the greenhouse for the winter (I'm in Zone 5). The past month they are looking bad, losing entire branches. Also rooted numerous cuttings from the original plants that did well until winter and have lost 75% of them in the past month.
I don't think I'm over watering, they are in constant 60 - 65 degrees. Maybe just short days? Any ideas would be appreciated.
Lost a different ming aralia last winter. Condensate was dripping off the ceiling of the greenhouse and drowned it.