I dont know wht the size is on your bedding plants but with my sunflowers I cut the top and bottom off 2 ltr plastic bottles and put them over the plant until they reach a good size.

I'd recommend a combination of a light sprinkling of organic slug pellets (those containing ferric phosphate) and going out after dark with a torch in your hand and boots on your feet. Pick off all the slugs you can find and stomp on them. You'll need to repeat this for several nights if you have lots of them.

If anyone had the real answer to this they would be millionaires!

Search 'Garlic Slug Control' in the search box above. It does work as they dont like garlic.

I surround my emerging Dahlias with broken eggshells, sunken beer baths nearby are said to work too. But mostly I think the frogs in my garden stop them.

Yes, I agree about frogs.
Of course we are far from slug-free, who is, but having a pond or two definitely helps. They don't need to be big. When we get really cross just now and again we use pellets very sparingly.
Great for cats too who will hunt the frogs - even more fun!

I've had great sucess with nemaslug - microscopic eel worms that infect slugs and to a lesser degree snails - you mix it up in a watering can and dose the soil. The effectiveness of the treatment is affected by the weather conditions but when it works its brilliant. When the slugs start feeling poorly they disappear underground to die so you don't have to dispose of the blighters bodies and as they decompose the eelworms which have been breeding inside the slugs are released into the soil ready to latch onto more slugs!! Of course safe for cats. Shouldn't be used very close to ponds. Expensive but then so are plants and I have lost so many plants over the years trying other methods that I now consider myself to be AT WAR! For the previous two years nemaslug has worked very well and this year the slug and snail population is very very low.

Also I protect the raised beds I use for veggies with a metal tape attached to a small battery so any slugs and snails get a small electric shock and fall off the sides of the beds.....so they can't climb in.
www.electricfencingsolutions.co.uk/SnailAway

Another thought which I suggested on a different question is to grow something for the slugs to eat and make access to it easy... salad leaves should work.

Thank you very much for your help, I will work my way down the list and see which method gets my slugs the quickest as the plants are vanishing before my eyes.