Ask Mr. Smarty Plants

There is an array of methods for controlling slugs and snails beginning with simply picking them off the plants as you find them, trapping them with homemade attractants and killing them, physical barriers, importing natural enemies and the use of commercial chemical repellants and and toxic baits.  The University of California Integrated Pest Management UC IPM Online has a thorough guide to snails and slugs in their "How to Manage Pests" series.

You can read about several methods of organic control from Mother Earth News (which include placement under plants of "crabgrass cookies" made from chopped up crabgrass leaves, corn bran, cornstarch and beer—a substance in crabgrass is toxic to slugs).  You can read How to Kill Snails and Slugs—The Definitive Guide from Weekend Gardener Monthly Web Magazine, January 2013.  It has descriptions of a wealth of organic methods plus several chemical methods. 

In Control of Slugs in Strawberries by Mark Bolda you can read about two of the commercial chemical control methods, one of which has metalaldehyde as the active ingredient and the other which has iron phosphate.  A note of caution:  Metaldehyde is toxic to birds and mammals (including humans, dogs, cats and wildlife) when inhaled or consumed.  The baits containing iron phosphate are advertised as being non-toxic but you might be wise to read this article by Bill Meyer, Iron Phosphate Slug Bait–How Dangerous Is It in the Garden?

You can find more articles on the internet on control of slugs by googling "Control of Slugs".  Whatever method or methods you choose, persistence seems to be the key to control.