How do you divide a phormium

I have a pot bound variated geen/cream arching phormium. I could re pot it but its already big and I wondered if I could get another plant out of it. I tried cutting through the roots which was very difficult but the baby plant died. TA

 

The easiest thing to do is to turn the plant out of the pot and tease it apart, using 2 forks back to back if necessary. Replant the new sections into their own pots and water well.

 

I have tried this but the roots are thick and I couldnt even cut them apart with a carving knife.

 

Axe? :D

 

Yip .... I would take an axe to such a monster, and then possibly an old saw? if necessary

 

Would you do it now or wait until Autumn.