Belcarra Garden Club
BC, Canada

Slugs and Eggshells
By Nora Boekhout and Les Bramley

Well here is a true gardener…   Les was inspired to write about his garden experiences while in Kona (but on a stormy rain-soaked day)!

Eggshells are made up of Calcium 34%, Magnesium 0.3%, Phosphorus 0.04%, Potassium 0.03%, Sodium 0.05% and 5% organic matter. While these nutrients are useful to our plants, they are very slow to break down and be beneficial.  We spread Dolomite Lime on our Vegetable garden for our plants’ calcium needs, usually around February.  We crush our eggshells and put them in our compost bins along with our coffee grinds.  We’ve read the coffee grinds are an aphrodisiac for the worms!

Enough said about that… back to slugs.  Some people say eggshells do not stop slugs. Our garden has its share of slugs but not in the Veggie section, which is covered in our eggshell compost. We water early in the morning and then again around 1pm when needed.  We let the soil surface dry for the night time because "that is when the slugs really go to work".  We also keep the pathway grass and weeds cut very short around the Veggie Garden.  We are lucky to have many little snakes and ground beetles, which eat the slugs.  We feed the birds year round and they seem to help as well.

Around March, when we notice that baby plants in our greenhouse are being eaten, we put a little slug bait down on the floor.  The greenhouse is the only place we use slug bait, as we don't want the birds or animals eating it.  



I (Nora) decided to do a little investigating online.  Our local slug fiends are the Pacific Banana Slug, the Giant Garden, and the European Black Slug.  I never liked the look of the eggshells in my containers and garden, so I also add my crushed eggshells to my worm bin instead.  I was surprised to read that the eggshell trick may actually be a myth.  The slug’s heavy mucus lets him slide right over sharp edges, even glass. You can see the experimental proof online!  If there are traces of the egg’s membrane present, it will actually attract slugs!  Nonetheless, there are also other people who still use eggshells as a deterrent.  Be sure to crush your eggshells into small “bits” and make the eggshell barrier wide, as slugs can stretch a long way!  Coffee grounds have also been suggested as a deterrent.

My personal “battle strategy” is to make “slug rings” around my “slug favourite” plants.  I use copper mesh (from Lee Valley) around the bottom of the containers on my deck.  For those bigger pots, I put the copper mesh around a smaller plastic pot with the bottom removed and sink it into the soil.  This has been very successful in keeping slugs from decimating my new dahlia shoots!   Out in the garden, I have used slug rings in conjunction with coffee grounds.  This year three “tasty dwarf  hostas” were finally able to survive AND flower!



Common online tips for slug problems are:  clean the area around your plants where slugs might hide,  keep a vigilant “slug patrol”, water in the mornings,  use slug bait that is animal safe,  use barriers around sensitive plants as a deterrent,  encourage predators, and grow plants they don’t like (lavender, ferns, lantana).  

Experience and discussions with our garden club members are the best resources!
Good luck and be sure to give our BGC any other tips you might have!


Related Links

Will Crushed Eggshells Keep Slugs Out? (

Warning: Eggshells Actually ATTRACT Slugs - Laidback Gardener 

Get Rid of Slugs in the Garden | Easy 6 Step Plan (

 17 Ways to Get Rid of Snails and Slugs (with Natural Ingredients) | Pest Control FAQ

12 ways to deter slugs

Lee Valley – copper mesh


Wonder of Slime - Slugs & Snails on a Razor's Edge - YouTube

Banana slug: 
ADW: Ariolimax columbianus: INFORMATION (

Leopard Slug - The Animal Facts - Appearance, Diet, Behavior, Habitat

Black slug - Invasive Species Council of British Columbia (




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