Time yet. Some of mine came in in Dec and stayed will be had the cold snap that killed off that growth. I have 6 and can see growth on 4. The other 2 seem turgid when I give them a prod, so am not worried yet. I suggest you do the same, poke your finger into the pot where the growths come up and see if it is rotting or turgid and either remove or leave them.

the ones in my pots are up but they are in more sheltered areas. The ones in the ground are at various stages, some up by 2cm and some not at all. Though gentle excavating shows had points :o)

I grow several varieties of hostas. Some have been showing their heads for 2 weeks others.... no sign yet.

Another week or two and they should be up

Ours have been up for about a month now, but have been stopped in their tracks by a return to very cold weather. In fact, originally I thought they had died and was tipping the compost out of the pots and found the roots and a few little shoots. I couldn't even remember what they were!

Some of mine are well up while others are not. They're all in tubs, all in the same place, they just come through at different times. You'll just have to be a bit more patient Chris!!

Ours are thinking about appearing... hopefully soon to feed the slugs!

You have all put my mind at rest.
Many thanks, I shall give them a little longer before I give up on them! I shall let you all know if and when I see shoots!

P.S.
I was given advice by a local grower of hostas who usually wins a gold medal at Chelsea [Bowdens Hostas] and he advised me to put slug pellets around hostas on or around Valentine's Day. They always do this apparently.

I'd much rather the slugs breakfasted on hostas than some of our other plants to be honest.

My pots of hostas overwinter under glass; they have just started into growth.
If your hostas are in pots, you can protect them by putting copper round the top of the pot (you can buy rolls of this with a sticky backing at Garden Centres). Alternatively, stand the pot in a large saucer and put a couple of inches of water in it. Make sure there is always water in the saucer and your hostas are safe (slugs haven't learnt to do breast stroke!)