A solution called renardine in which you can soak small offcuts of soft pine or conkers(horse chesnut)for a few days then scatter around your plants , this will deter ground burrowing bastards if placed in their holes or pathes.

...think you have gophers? also rabbit & deer for several months . Terrier men have used it to drive out foxes from thier land so the bastard blood brigade can hunt fox .

Also cresote or timber preservatives can work.
Beer for slugs too. They will bypass all plants to get to it , usually placed in a pot saucer sunk in the ground, I find coffee jars, etc, etc... work better and i suppose a drowning inebriated slug dies happy....