Treatment Plans
Eliminate slugs and snails
Why do these night-time visitors devour your leaves, and how can you stop them?
The problem
Slugs and snails are moisture-loving gastropods. They are mainly nocturnal, hiding by day in dark, cool places and emerging at night to feed. Their damage is easy to recognize: irregular holes in tender leaves and shiny, silvery slime trails on plants, pots or soil. These reveal where they have been. They voraciously attack delicate parts such as young leaves, tender stems and sometimes flowers.
Their presence often indicates excessively damp conditions around your plants. Fortunately, this is an easy problem to manage.
Their life cycle
These molluscs are hermaphrodites, possessing both male and female reproductive organs. However, mating between two individuals is generally necessary for reproduction. One slug can lay 100 to 500 eggs during its lifetime, often in clusters in damp soil or beneath shelter such as your plant's pot.
| Stage | Estimated duration | Detail |
|---|---|---|
| Egg laying | All year (peaks in spring/autumn where these seasons apply) | Lays up to 500 eggs in clusters in damp, sheltered soil. |
| Hatching | 2 weeks to 3 months | Timing depends on temperature. Warmer conditions speed it up. |
| Juveniles | Several months | Young resemble miniature adults and start feeding immediately. |
| Adults | 1 to 2 years | Reach sexual maturity within a few months and the cycle begins again. |
Controlling adults helps, but disrupting egg laying is also necessary for a lasting solution.
What to do now
- Inspect your plants in the evening with a flashlight or very early in the morning, when gastropods are most active.
- Remove every slug and snail you find by hand. This is the most direct and effective short-term method.
- Create a physical barrier around the plant's base. Sprinkle a ring of crushed eggshells or diatomaceous earth; their sharp edges discourage crawling across.
- Set a beer trap. Bury a small container (such as a yogurt pot) at soil level and half-fill it with beer. Attracted by the smell, they fall in and drown.
- Check traps and barriers every morning for a week, removing captured individuals and replacing bait or barriers as needed.
Prevention
- Water plants in the morning rather than evening so soil surfaces and foliage dry before nightfall.
- Avoid leaving standing water in saucers.
- Remove potential hiding places such as dead leaves and plant debris around pots.
- Ensure good air circulation between plants to reduce ambient humidity.
Common problems
- Snails and slugs · Nocturnal pests leaving shiny slime trails on leaves.
FAQ
Where do slugs and snails inside a house come from?
They most often enter through cracks, vents or open doors, especially on damp nights. They may also hitchhike in a new plant's potting mix or hide beneath pots brought indoors from outside.
What is the difference between a slug and a snail?
The main difference is visible: a snail has an **external spiral shell**, while a slug has no visible shell. A slug actually has a shell remnant, but it is internal and very reduced. Both are gastropod molluscs.
Does a beer trap really work?
Yes, in small areas. Slugs are strongly attracted to beer's **yeasty, fermented smells**. Its range is limited to **1 or 2 meters (about 3.3–6.6 ft)**, however, and it can sometimes attract slugs from nearby. Use it for localised control rather than as the only solution for a large garden.
Do crushed eggshells really work?
This traditional method works as a **deterrent barrier**. Gastropods dislike crawling over rough, sharp-edged surfaces. Effectiveness varies; some informal studies show that very hungry slugs can cross, but it remains a useful natural, non-toxic and easy-to-install deterrent.
Is diatomaceous earth dangerous for my pets?
**Food-grade** diatomaceous earth (uncalcined and amorphous) is considered non-toxic and safe for pets if small amounts are swallowed. However, its fine dust can irritate lungs and eyes in both people and animals. Apply it carefully and prevent pets from inhaling it directly.
Are there houseplants that repel them?
Yes. Slugs and snails tend to avoid tough, fuzzy or highly aromatic foliage. Although better documented in gardens, plants such as **ferns**, **mint**, **rosemary** and begonias are generally less appetising to them.