Oriental lillies overcrowding?

[Roker lassie]

I potted up several oriental lilly bulbs in the one container a few years ago and they are not as big in flower this year so i think they need re potting. Can anyone tell me whens the right time to do this and how?

[Scarlet]

I'd repot in the Autumn when the foliage has died down, plant about 12-15cm deep. They also do really well in the garden border.

[Roker lassie]

Thats great to know, thankyou for the help and advice!