I have my Hosta is zinc pots and that stops them, unless the leaves get too big and allow Slugs to crawl up that way.

Not tried it myself, but I have heard using clipped hair around the base stops slugs from eating them as it sticks to their bodies and stops them.

Do you really want the answer,

Slug's snails onion /carrot fly / green & white fly,

All have one thing in common, 'attracted by smell'

The answer is to offer a much more appealing "Smell"

But in the case of slugs/snails you need to ensure they wont be able to return once they've tried the stronger smell
All you need do is fill an old plastic (at least 1inch deep)
butter tub with "ALE" and let the slugs enjoy a good drink,
they'll get drunk and drowned, ( Hence a deep tub)

Your job is to keep the "tubs" emptied of dead slugs each day and ensure the tub has a fresh re-fill of "ALE"

(remember its the smell that's attracting the slugs so fresh ale has a stronger smell than old Ale)

If you do this rather than using pellets you'll have a way of keeping the slugs etc under control,
"You'll not stop the slugs appearing" no chemicle's ive ever seen will stop them full stop,
But this method is an old one ive used for years, it works and infact it's cheaper than buying slug liquids and pellets.

The other point to remember is slugs dont like rough ground, so near to the hostas stem if the ground is covered with tiny sized grit, or holly leaf, anything thats sharp and rough this again will help.

Now, Hostas are water lovers and i grow mine in about 4" of water in the pond at work.

Try putting their pots in large, deep drip trays and keep them filled with water. As long as the foliage isn't touching anything, they'll be fine as slugs can't swim !!!

Commando ones can!

Is a slug just a snail going commando? ;-)

No thats a male slug sneaking out for the ale in the butter tub and his wife thinks he's shy and will never come out of his shell!

(little doe's she know)

Many thanks to all who responded, extremely interesting suggestions!

When I let the dogs out last thing at night I always remove any slugs which are in the vicinity of the hostas, and I have tried the suggestion offered by Timmy, ie the garlic receipe offered by Bowdens Hostas - this didn't appear to work either. I quite like the idea of the ale in the tub so I think I'll give this a try, thanks Dungy.