[NASH]

I seem to have loads munching the leaves at the moment, they are just leaving the veins of the leaf 

[Yorkie]

Slug pellets or organic methods (beer traps, half grapefruits etc etc)

[JohnB47]

I've noticed some tiny snails on my leeks recently. Slug pellets may not work on these if they just stay where they are rather than going down to the ground. I only have a few snails (I think!) so I'm planning just to remove them by hand but perhaps a drenching of that nematode stuff would work? Or is that just for slugs?