Back in May, one of my Phormium tenax plants started to put up two flower spikes.
These have grown taller and taller: one is now about nine feet tall, the other about seven.
Today, the first flowers are beginning to open.
It’s fine to let Phormiums flower – they are not like agaves that die once they’ve flowered. It’s also fine to “prune” them if they’re getting out of hand, although it’s difficult to achieve a very tidy result: the cut edges will always remain, but in time, they’re disguised to some extent by new leaves.