Thanks, Nhu, those pictures are wonderful. I just checked my clump of Amaryllis belladonna - outside, in the ground, since 2005 - which has never bloomed. Each year it produces a thick tuft of foliage made up of dozens of leaves, and this foliage passes the winter unscathed by cold because the plant is inside a cold frame. But so far, never so much as a bud. Nhu, you mentioned growing this plant in a pot. Can you tell us more about this? I remember reading that Thomas Jefferson tried to grow Amaryllis belladonna as a pot plant in central Virginia (USDA zone 7) but was not successful in getting it to bloom. (My apologies if I've gotten this wrong - it's been decades since I've read Thomas Jefferson's gardening diaries.) Just what is it which makes this plant so difficult to flower in eastern North America? Nhu, you also mention a temperature gradient. That confused me because if the plants were responding to a gradual cooling, wouldn't the plants at higher elevations bloom first? Or is there something about local conditions at Berkeley which cause the lower elevations to cool before the higher? Or do you think the plants require a certain amount of time above a certain temperature before they bloom, and they get that heat requirement sooner at lower elevations? Jim McKenney Montgomery County,Maryland, USA, USDA zone 7