I suffer with snails here - or it could be slugs. Look for slimy trails.

You could protect the stems by cutting the top and base off a plastic bottle, slitting down the side, and putting it around the base. Tie round it with string. Make sure there isn't a space at the bottom. This works for me...the snails can't climb up the shiny surface.

The other alternative is to cut a square icecream tub about 3 inches from the top and make the cut edge spiky with the scissors [like bunting]. The snails can't climb over the spikes. You can also put the bottom of the icecream tub under a pot to catch water.

Thank you both very much, there are no slimy trails anywhere near the clematis so I don't think it can be slugs or snails that are causing this problem.

I will however use your ideas for the protection around the base just in case the slugs decide to have a go at it.

Any further help or suggestions as to what can be eating my buds would be greatly appreciated.

I hope you find a solution, good luck and happy gardening!