The most popular method of slug and snail control used in the garden is slug pellets. The pellets are manufactured from cereal and yeast that lures the slugs and snails to them and they contain a poison that kills the slugs and snails after they have consumed the pellets.
There are three main types of poison used in slug pellets:
Metaldehyde – When slugs and snails ingest metaldehyde it causes them to swell up and dehydrate. They become immobilised and are prevented from returning to the safety of their daytime shelter and ultimately die. Metaldehyde can also kill slugs and snails merely through contact. It also has the potential to harm other creatures that eat the pellets and, in turn, creatures that eat the affected slugs and snails, such as birds and hedgehogs.
Because of the risks to wildlife and the environment, a ban on blue metaldehyde slug pellets was announced in September 2020:
Ban on the use of metaldehyde announced - Defra in the media
This is applicable across the whole of Great Britain. It will be phased to give growers time to switch to alternative measures.
From 31 March 2021 no further supply is permitted but distributors can still sell any stock they have in hand, and use can continue until 31 March 2022. From 1 April 2022 it will be illegal to either sell or use metaldehyde products.
Methiocarb – (BANNED from late 2014) this is about ten times more poisonous than metaldehyde. It poses a greater risk to wildlife.
It takes longer to break down which makes it a more persistent hazard. It can also kill other insects including slug eating beetles.
It is also damaging to earthworms.
The Soil Association will not certify any pest and disease control products. The use of ferric phosphate would only be permitted by the Soil Association on a highly restricted basis, following a special application by an organic producer.
Although there aren’t any slug pellets that can be used in the organic garden it doesn’t mean that the garden will be completely overrun with slugs and snails, reducing all our plants to slimy stumps. Slug pellets aren’t very effective at controlling slugs. They will only kill around 10% of the slug and snail population in the average garden.
Organic garden management relies on prevention always being better than a cure. In the organic garden we use a system known as Integrated Pest Management Control sometimes referred to as IPM. IPM systems use a wide variety of controls to keep on top of pests and diseases. They depend upon the gardener taking steps to build up food chains within the garden that will attract suitable pest predators into the area.