Short of more clues I guess you have answered your own question, most likely the slugs are the problem.

Yes it's Slugs - they're feasting on my Tulips on my back wall at the moment. Funnily enough they are not bothering with the Hostas's I have put out!

Slugs and caterpillars. I found 2 hairy caterpillars munching my Montana this morning. They are now over in next doors garden after a short flight...

thanks to everyone