If your flowers and plants are left with ragged holes and edges and you find slime trails on your walkways, you have snails, slugs or both. These insect are not beneficial to your garden and so eradication should be your goal. Because snails are fairly hardly and prodigious, your work will be ongoing to control their population.
As in our other articles, we strongly encourage the use of non-toxic and low-toxicity solutions to pest and weed control. Avoid using chemicals when other solutions are available. The problem with chemicals is that they often have unintended consequences. Chemicals may end up poisoning beneficial insects, pets, children or you. The chemicals end up in the soil and the water supply. They contaminate the soil and in some cases impairs the quality of your soil. If you are growing fruits and vegetables, they can end up in your food.
To start your control of snails and slugs, we recommend you simply collect them and destroy them, or place them in a plastic bag, seal and dispose of them. By collecting snails, you will make an immediate dent in their population. Snails are active in moist areas out of the direct sun. They are most active in the late evening, and so is the perfect time to collect them. Do this a couple nights in a row and then switch to once a week. This alone will have a significant impact.
If you water in the late afternoon or evening it leaves the ground just right for snails. Snails like moisture and by watering after the peak sun the ground stays moist longer. Water in the morning. This gives the water time to soak in and excess water to evaporate.
You can create barriers for snails using copper strips or copper tape. Snails do not like to cross copper and so it effectively keeps them back. You can wrap copper strips around pots, tree trunks or as a ground based barrier to create an enclosure.
You can keep snails off your plants by covering plants with garden cloth. It allows in sun and water but keeps out birds and large insects.
If you must use a chemical control, we recommend one that is based on iron phosphate. It is effective at killing snails although it takes about a week to see results and must be reapplied about every two weeks. Iron phosphate based poison is less toxic to other organisms and so is preferable to other poisons.