In addition to being unattractive to look at, slugs and snails can be destructive to many flower and vegetable gardens. If the dahlias in your garden have ragged holes in them, there's a chance you these common pests have visited your garden. Slugs and snails are easily killed by poisoning or crushing them, but you must employ several methods simultaneously to keep them from taking up permanent residence in your flower garden.
Eliminate as many hiding places as possible. Slugs and snails are often found in dark, moist areas under yard debris, including stones, boards and low-lying branches. Clearing away these areas makes the yard less hospitable to slugs and snails.
Mow the lawn regularly to keep the grass low. Remove tall weeds.
Remove compost piles or place compost in metal containers rather than on the ground. Decaying matter is a source of food and shelter for snails and slugs.
Install copper tape or barriers around flower beds that are most attractive to snails and slugs. Copper creates a chemical reaction that shocks slugs on contact. Copper tape and copper slug barriers can be purchased at garden supply stores.
Adjust your watering schedule. Slugs are most active at night. Watering your garden in the evening keeps it moist at night, creating an environment that is favourable to slugs and snails. Water your garden earlier in the day so that it dries before nightfall.
Locate or relocate flower gardens and vegetable plants in open areas where there are limited hiding places for snails and slugs to breed and thrive.
Install a bird bath or bird feeder. Many birds enjoy eating snails, slugs and slug eggs.
Place baits in areas where a high population of snails and slugs have been observed. Make a simple bait by filling a shallow container with beer, half-covering it with half a grapefruit. Slugs and snails will be attracted to the beer, fall in and drown. Beer traps effectively drown snails and slugs, but they also attract them to your garden; so use the trap to get rid of existing pests and then discard it.