KILL SLUGS AND SNAILS ORGANICALLY
One of the best substances to come on the market to control slugs and snails has been bait made with Iron Phosphate.
Iron Phosphate is an organic compound that is found naturally in the soil, and if the bait is not eaten by a slug or snail, the material simply breaks down into fertilizer for your soil.
Safety: It's totally safe to use around fish, birds, beneficial insects, and mammals. For several other organisms, including earthworms and certain ground beetles, no harmful effects are known.
It safe to use on food crops, ornamentals, lawns and gardens, greenhouses and no adverse effects to humans are known, plus iron phosphate is considered GRAS (generally regarded as safe for food use).
How It Works: It is applied as part of a pellet that also contains bait to attract snails and slugs. When the pests eat the pellets, the iron phosphate interferes with calcium metabolism in their gut, causing the snails and slugs to stop eating almost immediately. They die three to six days later.
Long Lasting: Iron phosphate is more effective than Metaldehyde (such as used by Ortho) because Metaldehyde ceases to work when it gets rained on or if you water the garden, whereas iron phosphate remains active even with repeat wettings, easily up to two weeks.
Where to Buy: Sluggo & Escar-Go are two products you can buy that consist of Iron phosphate. We use Sluggo and have been very happy with it.
Keep in mind, they are not initially as cheap as Metaldehyde based products, but because iron phosphate remains active longer, it requires less to be used to kill more slugs, so in fact it is cost-effective.
For 13 more organic methods to kill slugs and snails read:
How To Kill Snails and Slugs - A Definitive Guide