I'm asking this question on behalf of a workmate who is having some
trouble getting his Agapanthus to flower.

He has three, all in pots, but only one is not flowering.
There's plenty of lush green foliage, but no flowers.
This is its third year now and in the first it had one flower but since
then nothing.

The pot it's in restricts its root run since this is meant to induce
flowering, and it's in full sun in well drained compost, so any ideas
what he could try to get it to flower?

Thanks in advance,
Tony.