I'll try that. And that's given me another idea! I might see if I can dig out some grit for a surface 'mulch'. They won't want to drag their little feet over it. I had grit a while ago, but I'm probably all out of it now:-(

I saw the most glorious delphinium today, but I had to let it go. I could just hear the slugs and snails smacking their lips in anticipation...