Controlling Snails and Slugs in Your Garden

By Deborah Rankin, J Bar D Ranch


Gardening has its challenges and one of those is combating snails and slugs; they absolutely thrive in the moist, humid environment of the Texas Gulf Coast. Snails and slugs are nocturnal feeders so they may rarely be seen feeding but if you find slime trails around your garden area and holes chewed in your leafy, green garden plants you can be certain snails and/or slugs are somewhere in the vicinity.frog


There are many methods available for combating snails and slugs in the garden – chemical applications, habitat modification, direct intervention, and the introduction of natural predators.


Metaldehyde is the most common chemical used for combating snails and slugs; however, there have been reports of children, pets and bird poisonings (some fatal) from ingesting this chemical. If used, extreme care should be exercised in following all the manufacturer’s recommendations!


I lean towards integrated pest management (IPM), especially the environmentally friendly methods for the sake of my dogs and honey bees. For example, iron phosphate is a common chemical, everywhere in nature and it does not readily dissolve in water. It is not harmful to humans, birds, animals or the environment. When applied to the soil in pellet form also containing bait, snails and slugs are attracted to and ingest the iron phosphate pellets. The iron phosphate interferes with their digestion – the snails and slugs stop eating and die within a few days. I purchased iron phosphate from a local garden center and was very pleased with the results.


Some of the iron phosphate products available contain active ingredients other than just iron phosphate. As with all substances you are going to place in your garden – whether a pellet, spray, or powder – take the time to read the product label carefully and completely. Identify the product’s target pests, how to correctly apply the product, and any known hazards with its usage before you introduce it into your garden! I often research active ingredients separate from product labels to get a broader spectrum of information – and am often surprised over the results of these independent searches.


Another approach is to alter the environment which snails and slugs use as refuge and breeding grounds by removing debris and dense ground cover, such as ivy and other succulents, stacks of boards and wood, and large wood chip mulches from the garden area. Thin out the plants to improve air and use a mulch containing materials with thick, jagged edges, such as eggshells. Snails have soft underbellies and will avoid anything sharp or prickly.


Try utilizing barriers such as a simple line of table salt around the outer garden bed, wood ash, diatomaceous earth, sawdust, copper backed paper or sheeting, sand, sulphur, animal or human hair, pine needles, thistle leaves, or straw. Keep an eye on your barriers as some of them may need to be re-built from time to time, especially after a hard rain or strong wind. Table salt, while very effective in combating snails, is fatal to plants. It should be used sparingly and never applied directly to the garden beds. Instead lay a small line of salt on a driveway or sidewalk that appears to be a regularly traveled path for the snails.


Set traps – snails love sweet things such as sugar water, fruit juice, soda pop and believe it or not, beer! For a homemade trap, using one of the liquids partially fill a plastic pot with a tight fitting lid and slots cut into the side, bury it in the ground to the level of the opening. Snails fall in and are incapable of getting out of the trap. Additionally, small boards raised slightly (1 inch) off the ground serve as effective traps. Snails will attach themselves to the boards during the day and can easily be found and destroyed. Commercially made traps are also available through garden centers and the Internet.slug


Do hand combat – go out to the garden, find, and hand pick the snails from your plants and surrounding areas, such as trees, walls, and stones. Drop them in a container with a lid or a bucket of water a using 3-5% concentrate of rubbing alcohol to keep them from escaping from the container. Once captured, you can easily destroy the snails by dropping them in salty water or crushing them.


Bring in the support troops – fortunately snails have many natural enemies; among them are frogs and toads. Whenever possible, create a small pond in the garden to encourage frogs and toads to make their home there. The smaller ones love self-watering pots. Frogs and toads are great – no plant damage and they eat other garden pests, as well as snails! Chicken, ducks, and guinea hens consider snails a tasty snack; people who own and allow them to free range seldom encounter snail and slug problems on their property.


And lastly, consider some plants for your garden that are less prone to snail damage such as ornamental grasses, impatiens, rosemary, sage, lavender, begonias, nasturtiums, narcissus, geranium (cranesbill), alyssum, roses, daylilies, and hydrangea.