Cut Flowers

I have some Acidanthera in pots somewhere in the garden. They always surprise me when they flower as I can never remember their name. They came in a job lot of bulbs some years ago and have received no TLC whatsoever.

From what I have been reading they need to be split up every couple of years or else they produce leaves and fewer flowers? Its also mentioned that they need a long growing season so I will need to get them in soon, and wor Bob reckons they are best grown in a greenhouse.
Your climate must be a good bit warmer than mine if they are thriving outdoors methinks. What size pot have you got them in veggie?