Biological control of slugs

The nematode Phasmarhabditis hermaphrodita specifically attacks slugs. Available by mail order or in garden centres, this nematode enters slug bodies and infects them with a fatal bacterial disease. Apply in the evening from spring to early autumn on moist soil when temperatures are between 5-20C (41-68F).

Encourage natural slug predators like birds, frogs, toads, hedgehogs, slow-worms, and ground beetles into the garden. Rake over the soil during winter so birds can eat slug eggs that have been exposed. Provide a pond or other water body where tadpoles can develop. It is helpful to have at least one side of the pool that gradually slopes up to dry land. This enables the young amphibians to leave the water in mid summer once the tadpole stage is over. Small amphibians can be heavily predated by birds, so grow plants around the pool to provide some cover. Also give them a place to overwinter. Log piles provide good shelters but frogs, toads and newts will also find suitable places in hedge bottoms, compost heaps and under stones. Sometimes they will hibernate in the bottom of ponds. To avoid disturbing amphibians, especially in the hibernation period, ponds should not be cleaned out unless this is really necessary. Hedgehogs like dense undergrowth and grasses for hiding and nesting. You can also build or purchase hedgehog homes.