The best time is early spring just before it wakes up - late March - Early April.

Is it in the ground or in a pot?

its in a very large tub. Urbarite. regards Nellie

Has it grown too big for the pot or are you wanting to have more plants elsewhere? If it's healthy in the pot I (personally) wouldn't disturb it - i think they look better when they have filled the pot.

There are good instructions on Sue Proctor's website
http://www.sueproctorplants.co.uk/growing-hostas.html (and they're based in Huddersfield so you know their advice will suit you over the border in Lancs.)

Hi 'Urbanite' no i don't think its too big for pot, did just want to get more plants! but i will take your advise and leave it be thanks again regards Nellie.