Bob, that's perfectly logic for a night blooming plant, as under such conditions the naturally white flowers would be most visible. On the other hand, pollinator insects would be in heat about the same periods. > Christian, > > I can attest to the fact that my Night Blooming Cereus blooms every month at the time of the full moon, from May until September or October. I have watched this phenomena for years and find it very consistent. Though it may have a number of flowers during a given flush, they will all open with the full moon or 2 days either side of it. >