Mini greehouse slugs

I have a small back garden and a small allotment plot, I use 2 of the plastic mini greenhouses (4 tiers) to start most of my crops off.  I have just been out to have a quick look at everything and find slugs have eaten 3/4 of my tomato seedlings.  I won't use pellets as I have a cat that is very curious, so how do I stop them.  Beer traps work fine when buried in the dirt but of course my greenhouses are sat on my flat patio.  I have tried eggshell in some of my outside pots of luttuce and the damned slugs and snails just crawl straight across.  Please help I am literally losing everything I have spent time and money on.

You can get wildlife friendly slug pellets that are very effective and go out after dark with a torch and pick off the offenders

Hope that helps

I cover the soil with grit which definately helps,try covering the shelves as well. Just make it unpleasant for little monsters! Good luck !

Thanks for the ideas, I'll try grit first I think and if that doesn't work I'll look out for "friendly" pellets.

A light scattering of cooking salt on floor inside your greenhouse will deter. Also 'Slug Off' - looks like granules of orange clay. Follow instructions on box.They dry up slugs slime. Have done wonders for my pots of hostas. Also crush dried eggshells with a rolling pin so they are very fine and add to compost as well as to tops of pots.  It's a ceaseless round, but keep going. Picking them off by hand may seem a bind too, but anything to keep the numbers down! Good luck!

You could also try putting copper tape around bits of the frame, if they're using the frame to climb up.  You may need 2 strips of tape about half an inch apart as some of the big ones can 'bridge' one strip of tape (even the really wide stuff.  If they're using the PVC to climb, you can also stick the tape to the frame (its cheap on ebay, cost me around £5 for 12 metres of the stuff.  You could also try scattering sharp sand on your patio, and make it as unpleasant as possible for the horrible things, and hope they'll go elsewhere for their free lunch.

I found a big fat snail sat in the middle of a pot in my mini greenhouse, I copper taped around the legs and all the way round the plastic cover on the inside which seemed to solve the problem.

Vaseline with garlic granules smeared over the base of the polythene, and round the legs will deter even the snails without a sense of smell.