John Hale, of Dunedin, asks :-
Even though it's deep winter, I'm seeing cabbage trees in full bloom. Is this unusual? Is it a sign of global warming? Does it portend anything about the weather in the short term?
Dave Kelly, a botanist at the University of Canterbury, responded.
I've been following cabbage tree flowering in Canterbury since 1997 and working with Bob Brockie who's been recording them around Wellington since 1990.
They vary quite a bit from one year to another, and the high-flowering years are sometimes the same in Canterbury as in Wellington. In both Canterbury and Wellington lastsummer was a particularly heavy flowering year, one of the four best in the last 20 years. But I think you you are noticing the fruit, not the flowers.
Flowering is in November-December, and this winter I've not seen any cabbage trees around Canterbury that have flowers on now at the "wrong" time of year. This can happen in some species if the seasons have odd warm and cold spells, but I've never seen cabbage trees do it. But the fruit is ripe on many trees right now (July), and is quite noticeable because it was such a heavy flowering year. The flowers and fruit are both white. The main way to tell if these are fruit is that there ought to be small squishy white fruit and seeds on the ground underneath a fruiting tree. The fruit are important winter food for silvereyes and blackbirds.