Slugs
Deroceras reticulatum; Limax spp.; Milax spp.
Soft-bodied shell-less molluscs that feed at night on seedlings and leafy vegetables. Worst in cool wet gardens.
Background
Several slug species are present in Australian gardens. The grey field slug (Deroceras reticulatum) is the most common in vegetable patches, feeding on a wide range of seedlings and soft leaves. Slugs are particularly hard on direct-sown seed and newly transplanted seedlings.
How to identify
- Soft mucus-covered body, no shell, grey to brown, 20-60mm
- Slime trails on soil and plants
- Feeding damage: irregular holes in leaves and tender shoots, often with mucus smears
- Hides under mulch, boards and pots by day
Life cycle
Hermaphroditic; lays clutches of 10-50 pearly eggs in moist soil. Eggs hatch in 2-3 weeks; maturity in 3-6 months. Multiple overlapping generations.
Weather triggers
- Temperature: 5-22°C
- Humidity: >85%
- Rainfall trigger: >5mm
- Peak activity on cool damp nights. Less active during dry periods.
Peak season (southern hemisphere)
Red = active season · Dark red outlined = this month
Affected vegetables & crops
Click any crop to see current prices and growing info.
Climate zones at risk
Organic & low-impact control
- Hand collection at night with a torch
- Beer traps or yeast-sugar traps
- Iron-based slug and snail baits
- Copper tape barriers for seedling trays and pots
Chemical control
- Metaldehyde pellets available but toxic to non-targets; iron-based baits preferred
Always read product labels — registrations change.
Prevention
- Thin out dense mulch around seedlings
- Remove boards, pot trays and other daytime hiding places
- Water in the morning
- Protect transplants with a ring of wood ash, coffee grounds or copper tape (partial deterrent at best)
Companion planting
No reliable companion plant repels slugs.
Biosecurity
Widespread and established.
Sources
- Sustainable Gardening Australia — Slugs and snails
- Agriculture Victoria — Slugs in cropping
Accuracy confidence: high. We update this library as new extension guidance is published.