Snails are molluscs with lungs, in our gardens there are various species, belonging to two large groups: the slugs, without shells, and the snails, with a large roundish shell. These animals feed on decomposing vegetables, grass, tender leaves, sprouts; generally they spread in the garden and in the garden during the spring and autumn months, since too low temperatures or the excessively dry climate cause their temporary lethargy.
Snails prefer damp and fresh places, and are present in the garden and in the vegetable garden, especially in the cool hours, at sunset and at dawn. Often during the hot hours they hide in shady places, between the pots or under the leaves.
Their diffusion can create discomforts especially in the vegetable garden, since they tend to feed on young seedlings and shoots, negating the work of the farmer, who can see decimation of seedlings and plots of carrots, broccoli, salad.
As for ornamental plants in general, snails do not present a serious threat, as they hardly devour the vegetation of an entire shrub or a medium-sized geranium; more easily ruin a seedbed or small annual plants recently placed at home.
Surely the most voracious snails are the slugs, which fortunately are stopped in their action by the heat and the summer drought.
How to fight them
Metaldehyde based baits have been used against snails for decades, very effective and rapid; in reality this product is highly polluting and also has the strong disadvantage of being toxic not only for snails, but also for all animals, including humans; therefore, the accidental ingestion of portions of bait can cause serious health damage also to domestic animals.
In organic farming the use of metaldehyde-based baits is allowed only if placed in traps where they cannot be consumed by superior animals; more easily we use baits based on iron orthophosphate, a substance also present in nature, non-toxic to humans or pets.
For some years now, nematodes have also been used against snails; a species of nematodes in fact parasitizes snails and snails and quickly leads them to death.
Without killing them
If we want to keep the snails away from our garden, but without killing them we can think of removing them manually, scouring the garden area during the coolest hours of the day; in this case we can also prepare a simple trap, using spent tissue or thin wooden boards to simply place on the ground: these shaded shelters will quickly become populated with snails, which always seek shelter from the sun. Hand-picked snails can simply be placed in an area away from our garden, so they take a long time to return.
Another very useful method for keeping snails away is in simple strips of plastic coated with salt; the snails keep away from the salt and therefore do not pass the strips; remember however that to have a lasting effect these strips must be replaced often because the salt dissolves easily with humidity.
Snails and slugs: Myths
For some years the fame of the beer trap has spread among the horticulturalists; consists of a container full of beer, to be buried to the brim; the snails are attracted by the smell of the liquid but fall into the container unable to exit; in the morning the snails can thus be moved quickly. In reality it seems that in some areas the snails are not particularly attracted to beer, and above all the snails seem almost immune from this desire to get drunk.