Mark, yes at the temperature I keep the greenhouse (55-F night) the trees flower and fruit year around, just as they do in the tropics. Many of my in ground trees are in bloom at the present time (Cara Cara, Dekopon, Valentine Pummelo, Ponkan Mandarin, and a Tango Mandarin. My in ground Marsh seedless grapefruit has started a general all around flush, and I can see tiny new flower buds at the ends of the flushes. After the blooms have set fruit, I will give the trees a foliar spray of low biuret urea.