Slugging it out with the Slugs

By Melanie Mathieson
Gardening Guru

Because slugs and snails prefer damp and cool weather, you will often find the most damage from slugs and snails on your plants in the north, or northeast and northwest gardens. Gardens with more shade and lower light conditions tend to harbour more slugs due to their moister conditions. Although we have had some stretches of the cooler weather the high humidity and frequent rains have also created favourable conditions for slugs.
Slugs and snails are very similar pests. Both range in size from 1/8” to 1 inch in size and can be grey, tan green or black, with or without darker patterned spots on their bodies. Snail’s have a coiled shell on their back which identifies them from slugs. Both lay round or oval clear eggs in jelly-like masses under stones and debris in the garden. Snails and slugs like to eat decaying plant matter but will also eat soft plant tissue, making large holes in foliage, stems and bulbs of many plants. When out in full force these pests can completely demolish seedlings and severely damage young shoots and plants. Wherever slugs and snails have been, they will leave a characteristically slimy trail of mucous, which is what often turns most people off of slugs and snails.
Keeping snails and slugs at bay are important if you want to prevent damage to your garden. As mentioned, usually the shadier garden sites can be more affected but any area or plant in the garden can be affected. Some favourite food sources are hostas and other large-leafed plants but your vegetable garden is also susceptible to damage. Good housekeeping in your garden can make a difference in reducing the population of these leaf-shredding pests. Remove any dying or decaying leaves from your plants and put in the composter. Ensure good air circulation around your plants throughout the season. Also encourage natural predators such as ground beetles, toads, lizards, garter snakes and many birds. Remember that ground beetles and fireflies eat slug eggs as a main source of nourishment.
Even when following the tips listed above some populations can still get out of hand so I have some other effective tips listed below for “slugging out slugs”.
1. Hand pick the snails and slugs from the plants as you see them. Slugs will congregate under planks, flat rocks, bricks or flowerpots so place a few around the garden and turn over each morning and collect the slugs hiding there. Citrus rind halves turned upside down can also attract many slugs. To dispose of your collection add to a coffee can of hot water with a few drops of dish soap added and then add to the composter when done. If you have a fishpond, your fish think of slugs and snails as a delicacy so feed them to your fish.
2. Many gardeners swear by the buried tin remedy. Save tuna or salmon tins and wash thoroughly. Place them in the ground so the top of the can is level with the soil. Add some beer (can be non-alcoholic) to about half way in the tin. Slugs are attracted to the smell of the beer and will fall into the tin and drown. If using beer with alcohol make sure you cover the surface of the tin partially with a flat rock or board so pets cannot drink the beer from the tins. Instead of beer you can mix your own yeast recipe using yeast for baking and following the package instructions for mixing and then adding enough warm water to half-fill the tin. Make sure you check this concoction after heavy rainfall or watering of your garden, as you may need to change it if it gets watered down.
3. Strips of copper flashing or copper tape is a great deterrent for slugs. You can custom make bands to place around the trunks and stems of trees, shrubs and plants or the edges of the garden. Before installing, make sure the area you want to protect is slug free. When slugs come into contact with the copper their slime creates a small electric charge when in contact with the copper.
4. Dry crushed eggshells are effective at keeping slugs and snails at bay. They also add nutrients to your soil. Save your eggshells, dry them out and then crush by hand or in the blender. You can add coarse sand to the shells if you need some more volume. Sprinkle the mixture along the boarders of your garden. Snails and slugs will not cross this barrier as it removes the protective mucous from their underbodies and scratches their underpinnings. Wood ashes can also be used in this manner and are great for the soil as well. Make sure to reapply after a heavy rain or watering.
5. Similar to crushed eggshells, is the use of diatomaceous earth, which is a calcium rich mineral dust, composed of fossilized diatom shells. This is sold at many garden centres and is a great source of calcium for your garden. The microscopic shells have razor sharp edges, that when laid on the surface of the garden soil will also remove the mucous and cut the underbodies of the pests when they cross the diatomaceous earth. Make sure not to breathe in the dust when sprinkling on the garden and to reapply after a heavy rain or watering.
6. A trip to your spice cupboard can provide another earth-friendly solution. Powdered ginger sprinkled on the soil in a continuous band around plants can be very effective. Pick up your supply at the bulk food store for larger and more economical quantities. This is not harmful to pets or people, but ginger is spicy hot and when in contact with the slug can create burning sensations that the pests do not like. Reapply often and as needed.
By using these few techniques you can ensure that your plants will not fall victim to slugs and snails this gardening season. Remember to be vigilant and keep on top of the pests and with a few minutes a day you will be able to successfully Slug Out Slugs!