There seems to be a little confusion as to whether Lilium regale or Lilium longiflorum is the Christmas lily in New Zealand, but I can’t see that it matters. My guess is that florists may refer to the latter as the Christmas lily because it commonly comes with pure white flowers and is a reliable standby for picking, much favoured in floristry. But many gardeners associate the regal lily with this festive time of year. It too has the wonderfully fragrant white trumpets but usually with deep red or purplish markings on the back of the petals. L.regale comes from the Szechuan area of China whereas L.longiflorum is from Japan.
There is nothing too difficult or rare about either. L.regale gets to just over a metre tall and generally we get away without needing to stake it, especially when it is grown in the rose garden and has some taller plants around it to prop it up if it starts to list too far. If you have both sun and good soil, you are fine and it should reward you with eminently pickable flowers to adorn the Christmas table. Like most lilies, the bright pollen falls off rather freely and will probably stain the white damask Christmas tablecloth. Apparently you can brush the pollen off the stamens if you are working in dry conditions. Alternatively, nip the tops off the stamens but leave the anthers in the centre. Don’t harvest the flower stem right back at bulb level. It needs some length left because the stem contains both leaves and flowers and the bulb needs its energy replenished through its foliage or it will waste away.