welcome to GoY.
sadly there isnt an easy way. grit/gravel will slow them down. you can put down deterrents or traps to collect them if you prefer.

Slugs and snails are every gardners' biggest problem. The worst are the little keel slugs which live below the surface of the soil and eat roots like potatoes.
Despite the effort involved, the only way to keep them effectively under control is to go out at night with a torch and pick them up while they are feeding. Or alternatively put down a lot of slug traps with beer or another sweet liquid in them.
Metaldehyde slug pellets are worse than the problem, as the slugs and snails that eat them and become immobilised are in turn eaten by birds and other predators which poisons them. (Unless you are meticulous at picking up the dead and dying slugs the next day before this happens.)
Copper tape or copper rings DO work really well at protecting the most valuable plants. So does common table salt if sprinkled in a ring around the plant, but of course this does salinate the soil if used too often.

Try putting some broken slate around them they don't like sharp edges,blue slug pellets,they're also supposed to stick to coffee hope this helps.

there are some wildlife friendly slug controls in the garden centre and I think that they won't cross copper -- someone makes copper bands to protect special plants like hostas which may protect your seeds, folk I know have created a wildlife pond to encourage frogs and toad hoping tp protect their veg patch! here's hoping

I'm using the copper bands to protect vulnerable plants. They are available on www.greengardener.co.uk

I find broken egg shell help around a plant, I rinse them and save all winter and of course the frogs and hedgehogs help.

I do exactly the same Drc726...We eat a lot of eggs in our house and i have bags full of them...I crush them and also throw them into the hole when im digging and planting..>)

Agree with Pamg and Andrew - copper is gd, if quite expensive and will not be effective indefinitely. I would say that a wildlife pond, encouraging frogs etc is the most effective deterrent. Attractive too, doesn't have to be a big fancy pond, ours is tiny and they still use it. Good luck.
What a shame we can't eat slugs, they are about as useless as the ****** ground elder!

If you have a couple of small bantams running loose in your garden they will eat the grubs and slugs and snails, they controlled mine very well, but the fox started to kill them now they are in a fox proof pen. You only need a couple to keep the pests under control, and only the smaller varieties because the bigger chucks trample down plants, Lavender Pekin or something similar, they are lovely as pets