Pest control of slugs

Some slugs are notable garden pests and there are various methods of controlling them. Commercial slug pellets containing metaldehyde or methiocarb are available, but are not approved for organic gardening as they can poison creatures further up the food chain. Aluminium sulphate can also be used and its proponents say that it is less toxic to the environment. Salt will kill a slug but washes away easily.

Slugs have an aversion to copper. Copper pipe can be used and commercial slug rings are available. A 15 cm length of plastic pipe with copper foil tape stuck round it can be used to protect individual plants. Slugs also find rough surfaces such as crushed eggshells irritating.

Beer traps can be used to drown slugs. Put a jar containing 1-2 cm of beer into a hole in the ground. The slugs will be attracted to the beer and will drown.

Comfrey can be used as a decoy. Put comfrey leaves round plants that need protecting. The slugs will eat the comfrey and leave the protected plant alone. This is a honeypot approach, and rarely effective as it merely increases slug populations in the longer term.

Encouraging natural predators will help to keep the slug population under control. A fairly recent development in the control of slugs is the introduction of 'Nemaslug', a microscopic nematode (Phasmarhabditis hermaphrodita) that will seek out and parasitize slugs, reproducing inside them and killing them. The nematode is applied by watering onto moist soil, and gives protection for up to six weeks in optimum conditions, though is mainly effective with small and young slugs under the soil surface. The nematode is only effective in warm, moist conditions, above about 20°C.

Finally, night time patrols with hand collection can be a useful measure, but for best results, several methods can be used together.

See also

• biological pest control

External links

• Metaldehyde at Pesicides News
• Nemaslug commercial web site
• Slug control fact sheet at HDRA