Hi Janm I know how you feel,don't think you've done anything wrong in the past I have a few hostas myself although I like the plant the slugs seem to love them more than me,they really can make a meal of the leaves try putting some slug pellets around them make sure you don't get any on the leaves,welcome to g.o.y.

Slugs do not really eat Hostas, it is snails that do the damage.
Grow huge numbers of hostas. then the damage is not so obvious!

Slug pellets still help enormously, snails eat them too, Owdboggy - then you have to spend ages clearing away the empty shells...

Thanks very much for your answers! So there is no secret? I just have to keep trying? x

You could also try the nematodes which kill molluscs.

No secret, Janm, just vigilance, diligence and a container of slug pellets;-))

Thanks again Everyone for your advice x

Try putting some cat buiscuits around your garden near hostas. My wife put some out for cat, i went out at night and there were loads of snails around the bisucits. Done the same following day and sure enough more snails around them, picked them up and threw them onto road, caught loads of snails (honest)