Slugs and Snails: How to Identify, Prevent, and Get Rid of Them
What Are Slugs and Snails?
Slugs and snails are molluscs, belonging to the same family as oysters and clams. Both are gastropods, meaning “stomach-footed,” because they move using a single muscular foot located on their underside.
The main difference between the two is that snails have a hard shell, which protects them from dry conditions and heat, while slugs are shell-less, making them more vulnerable to the sun.
Both slugs and snails have soft, unsegmented bodies that can grow between 2–4 cm (0.8–1.5 inches) in length. Their heads are equipped with tentacles — the upper pair with eyes and the lower pair for smell and touch. Slugs and snails are also hermaphrodites, meaning each individual has both male and female reproductive organs, allowing them to reproduce quickly under the right conditions.
Why Are Slugs and Snails a Problem?
Slugs and snails can cause serious damage to gardens, especially in moist environments. They are notorious for eating up to 40% of their body weight per day, feeding on seedlings, roots, and leaves of vegetables, herbs, and ornamentals.
Typical signs of infestation include:
Large, irregular holes on leaves and stems
Slimy, silvery trails left behind on plants and soil
Damage to young plants and seedlings overnight
These pests are especially active during cool, damp weather, or after light rain. Their main active season is from April to October, after which they hibernate until spring.
Where Do Slugs and Snails Hide?
During the day, slugs and snails seek out cool, dark, and damp hiding spots, such as:
Under mulch, rocks, or wooden boards
Beneath dead leaves or garden debris
In cracks, under pots, and among plant roots
They typically emerge after dusk or on cloudy days to feed.
How to Get Rid of Slugs and Snails Naturally
1. Clean Up Your Garden
Remove anything that gives slugs and snails a place to hide.
Rake away fallen leaves
Remove piles of debris, mulch, or boards touching the soil
Trim overgrown plants to allow sunlight to dry the area
A clean, sunny garden discourages slug and snail infestations.
2. Hand Picking (Best at Night)
The most effective control method is hand-picking slugs and snails about two hours after sunset.
Use a flashlight to inspect plant bases and leaf undersides
Remove pests with a spoon or tongs
Drop them into soapy water or rubbing alcohol to kill them
Just one hour of consistent hand-picking can greatly reduce their population.
3. Slug and Snail Traps
Create easy traps to catch these pests overnight:
Place grapefruit or melon rinds, or inverted flower pots, in the garden to attract them
In the morning, check and dispose of trapped slugs and snails
Use wooden boards or asphalt shingles covered with aluminum foil as shaded traps
Alternatively, beer traps are highly effective:
Fill shallow containers with stale beer and bury them so the rim is at ground level
Slugs are attracted to the smell and drown in the liquid
Place traps about 3 metres (10 ft) apart and empty them daily
Natural Predators
Encourage natural predators in your garden to keep slug and snail numbers in check.
Toads, snakes, ducks, birds, and ground beetles feed on these pests and help maintain ecological balance.
Effective Barriers Against Slugs and Snails
You can prevent slug and snail infestations using natural deterrents:
Crushed eggshells, sand, or wood ash: Irritate their bodies and discourage climbing
Copper barriers: A copper strip (about 5 cm high) releases a mild electric charge that repels them
Aluminum mesh or screening: Install 7.5 cm high and bury 2.5 cm deep around garden beds
These barriers are chemical-free and long-lasting.
Using Diatomaceous Earth
Diatomaceous earth (silicon dioxide) is a natural, non-toxic slug and snail control product made from fossilized algae.
Lightly dust garden rows and leaf bases — as slugs crawl over it, the powder dehydrates them.
⚠️ Keep the product dry and avoid inhaling the dust.
Chemical Control Options
Slug and snail bait pellets and powders are available at most garden supply stores. For best results:
Apply in the late afternoon or evening, when pests are active
Ensure soil and bait are moist to attract slugs
Always check the Pest Control Products (PCP) number on the label to ensure it’s approved by Health Canada
Read and follow all label directions carefully to ensure safe and effective pest control.
Summary: Best Ways to Control Slugs and Snails
✅ Remove Garden debris and moisture
✅ Hand-pick at night
✅ Use beer traps or melon peel traps
✅ Apply natural barriers like copper or crushed eggshells
✅ Use diatomaceous earth or safe, approved bait products
By combining these natural and preventive methods, you can effectively control slugs and snails in your garden and protect your plants from damage.