Hi, Lauw! Several factors are involved, which I should explain. Most of the clumps received some water this summer and most, but not all of them, flowered soon after receving a good watering, in July or August. I discussed this behavior here a number of months ago. It occurs after a dry winter. Without that watering in summer, almost no blooms appear. The particular clump that is blooming now did not receive any water until our recent rain came. Unlike all the others, it does not appear above ground. It was buried under a a one inch layer of gravel for reasons that do not need to be discussed, I think. All other clumps show the necks of their bulbs about 2 inches (5 cm) above the surrounding soil. The fact that it was buried was probably why it did not get watered in summer. As to whether the burial made an essential change (such as summer cooling) I simply do not know. November is quiet time for bulbs here, as it is in other gardens with mediterranean-like conditions. Oxalis, of course, is blooming at this time of year although it has never reached the interest of the public. Cyclamen and narcissi should surely provide good alternatives. I suppose it is cut-flower trade that may be looking for late blooming season for A. belladonna. In that regard, I'm not sure if my explanations will be enough for you. The conditions may not be simple to replicate. You would need to give the bulbs are rather dry winter season, to avoid summer water and then to bring them to life in late October or early November. As to what that would do to the bulbs themselves, I can only guess. They might not be able to repeat this annually and might need one well watered winter to restore them. Best regards Andrew San Diego