Its just the right time. Chop off pieces with a sharp spade and replant. Remember slugs love them and if Hostas are nibbled when they are tight buds they open up like lace doilies! Put a few slug pellets down at night but remove them and any dead slugs first thing in the morning so the birds don't eat them.
Thank you greenfingers - I would never plant Hostas in the ground - they wouldn't last five minutes in our garden - especially after dark when the little blighters come out for a midnight feast!