There are many species of snails, sometimes difficult to distinguish for a non-specialist. Snails (Gastropoda), next to cephalopods and clams, they belong to the mollusks (Mollusca).
In the garden you can find naked snails and shelled snails. They are widespread throughout Central Europe. Of the snails with a shell, the grapevine snail is the best known. Snails can often be found in the garden, however, hardly anyone knows, that their mucilaginous secretions stimulate plant growth. Unfortunately, the damage they cause, are much greater than the benefits.
There are many methods of controlling slugs. They also have many natural enemies. Nevertheless, they often do great damage to the garden. They prefer damp and shaded places, sheltered from strong winds. In the shady garden, where, as a result of too dense planting of trees or shrubs, the access of light and air is difficult, it is worth removing at least some of the branches. There are several different ways to combat slugs; they can be used separately or combined.
An effective way to combat snails is collecting. Planks are laid on damp paths between the flower beds. During the day, snails gather under them, which can be easily removed from individual boards. At the end of summer, you can lay out balls of wood wool next to the paths, in which the snails lay their eggs. By collecting and burning this wool, we destroy a significant number of this pest's eggs. Usually, snails lay their eggs near the compost heap, and if allowed to do so, we should not be surprised, that we will have a lot of snails in the garden. Snails like horseradish and are happy to flock around this plant. Experienced gardeners spread slices of raw potatoes on endangered beds. It is a treat for both snails, and the wireworms, which also feed at night. In the morning, we can collect the remnants of potatoes along with pests and destroy.
Snail covers can be set up around the entire garden or only around specific places, preventing them from accessing from the neighborhood. Even live shields are used.
Scattering of quicklime or algae, sawdust, mineral flour, dry spruce needles, wood ash or very fine sand makes it difficult for the snails to move. These pests need to secrete more mucus, which greatly weakens them.
One of these means is sprinkled on a narrow one (10—15 cm) a strip around the flower bed. You must repeat this operation after each heavy rain. Noticed, that snails don't like white mustard. Other plants also have a deterrent effect on them, like ferns, elderberry, tansy, horsetail, yarrow and thuja twigs; it is enough to spread the fresh parts of these plants among the crops.
A good remedy against slugs is the water extract of fir seeds (Abies alba). On 1 l of water are enough 3 g nasion. The seeds are boiled in water, sets aside for the night, and the next day, you can spray the endangered plants. This provision was given by Steiner in 1924 r.
The collected snails can also be used to prepare a liquid that repels these pests. Snails are thrown into freshly prepared cold nettle extract (60 pieces on 8 l liquid), the whole is fermented by 3 days, stirring several times during this time. After 3-4 days, such a liquid can be used to spray the soil surface. As our experiences show, the sprayed beds are not visited by slugs. Various snail traps can also be used. Beer is a liquid that strongly attracts snails. For shallow bowls or plastic cups, which sinks into the ground around the beds, we pour beer, where the attracted pests melt. A device for catching snails was released for sale, under the name Ex-Arion. It works in a similar way to the beer trap. It differs in the additional cover of the vessel.
The hedgehog is one of the most important natural enemies of snails. It also regulates the number of insect larvae. Lizards and frogs also feed on snails. Ducks also like to eat these mollusks, so it's worth keeping a few ducks, especially there, where is a lake or other water reservoir. However, you must remember to protect fresh sowings or young plants from ducks, preferably with a portable plastic fence. Older plants are not damaged by these petals. The predatory snail Daudebardia rufa is found in southern and central Germany. It feeds on arthropods, other snails, and even individuals of their own kind. It is worth collecting snails of this species and placing them in the garden.