Here are a few suggestions I found in a book I have - "1001 All-Natural Secrets to a Pest-free Property":
*Steep crushed garlic cloves in a solution of 3 tablespoons Ivory liquid dish soap or Dawn Liquid dish soap and 2 cups boiling water. Strain & place in spray bottle. Spray over plants; repeat after rainfall.
*Sprinkle dry cornmeal around base of plants - bugs will eat it & not survive
* Mix 1/2 cup salt with 1 cup all-purpose flour. PLace in jar with perforated lid or small burlap sack. Sprinkle powder over the plants early in morning when dew is still on the plants.
*Pour beer in a tin pie plate near the plants - slugs will drink it & not survive.
*Different pest - I mix Tobasco sauce, turmeric, dish soap & water, strain well (turmeric can plug spout) and put in spray bottle. I spray my flowers to keep deer from chewing up all the blossoms.
I'm not in favor of killing all garden pests, but some would kill all the food I put up from the garden if we didn't practice common sense about getting rid of the garden-destroyers.