A coffee solution sprayed on plants or watered over the soil can repel or kill slugs and snails.

A spray solution of 0.1 percent caffeine (a cup of instant coffee contains about 0.05 percent caffeine) will repel slugs, and a solution of 1-2 percent will kill them.

It is not known how caffeine kills the molluscs, but it seems to damage the nervous system.

Applications can cause leaf-yellowing on some types of plants.

Note; The Food and Environment Protection Act 1986 makes it illegal to use any chemical as a pesticide in Britain unless it has been approved for that purpose.

This applies to all would-be pesticides, even something as innocuous as coffee.