Biological protection of gardens against snails

Snails can cause significant damage to plants in your garden, affecting your harvest and the aesthetics of your green space. They can devour leaves, fruits, and vegetables, leaving behind trails of silvery slime. Fortunately, there are biological and sustainable solutions to combat these pests without resorting to harmful chemicals.

Understanding Garden Snails

There are several types of snails that can invade your garden, including slugs, shelled snails, and land snails. Slugs, recognizable by their soft, elongated bodies, are often the most devastating. Shelled snails, on the other hand, are characterized by their spiral shells. These mollusks feed on leaves, fruits, and vegetables, leaving behind trails of silvery slime.

Snail Life Cycle

Snails reproduce by laying eggs in moist, dark soil. Each snail can lay up to 100 eggs per year. The eggs hatch in a few weeks, giving birth to young snails that feed and grow quickly. They prefer humid and shady environments, hiding under leaves, stones, and plant debris.

Conditions Favoring Proliferation

• Moist and compacted soil promotes snail reproduction and development.
• Shady and poorly ventilated areas provide ideal conditions for their habitat.
• The presence of dense vegetation, plant debris, and weeds creates refuges for snails.

Biological Methods of Snail Control

To effectively control snails, it is important to understand their behavior and implement strategies that prevent them from settling in your garden.

Natural Predators of Snails

Nature offers a wide range of predators that feed on snails. By encouraging their presence in your garden, you create an ecological balance that naturally limits the proliferation of snails.

Animals

• Hedgehogs are voracious consumers of snails and slugs. A hedgehog can consume up to 500 snails per night.
• Frogs and toads, as well as lizards, are effective predators.
• Some birds, such as tits and blackbirds, also feed on snails.
• Ducks and chickens can be introduced into the garden to control snail populations. A chicken can consume up to 50 snails per day.

Insects

• Ground beetles are nocturnal predators that feed on snails and slugs. They can consume up to 10 snails per day.
• Ladybug larvae are formidable hunters of snails and aphids.
• Earwigs are known for their appetite for snails and slugs.
• Hoverflies, whose larvae feed on aphids, can also contribute to the fight against snails.

How to Attract Predators to the Garden

• Create shelters for hedgehogs, such as piles of wood or nesting boxes.
• Set up water points for frogs and toads. A small pond or a shallow saucer filled with water is enough.
• Install feeders and waterers for birds. You can also plant fruit trees to attract them.
• Plant hedges and shrubs to provide habitats and food sources for predators. Native hedges are particularly beneficial for biodiversity.

Physical Barriers

Physical barriers can prevent snails from accessing your plants and sensitive areas of your garden.

Natural Materials

• Crushed eggshells, sawdust, sand, wood ash, coffee grounds, pine needles, and coffee grounds can provide effective barriers. These materials create a rough surface that is unpleasant for snails.
• Diatomaceous earth, a natural product made of algae fossils, can also be used as a physical barrier. It acts by dehydrating snails, killing them by desiccation.

Artificial Materials

• Copper strips, placed around plants, can deter snails. Copper releases ions that are toxic to snails.
• Fine mesh screens, installed at the base of plants, can prevent snails from reaching them. Make sure the mesh is fine enough to prevent snails from passing through.
• Plastic barriers can also be used to delineate sensitive areas. Plastic barriers should be high enough to prevent snails from crossing them.

How to Use Them Effectively

• Place the barriers around sensitive plants, ensuring they are continuous and uninterrupted. It is important to create a complete circle around the plants to prevent snails from bypassing them.
• Regularly renew the barriers, especially after rain or watering. Natural barriers can be washed away by rain or watering and should be replaced regularly.
• Combine different protection methods for better effectiveness. For example, you can install a copper barrier around a plant and then cover the soil with crushed eggshells.

Traps and Repellents

Traps and natural repellents can help control snail populations in your garden.

Snail Traps

• Beer traps, consisting of containers filled with beer, attract snails that drown in them. You can use plastic pots or glass containers. Place them at ground level in areas where snails are present.
• Mixtures of flour and yeast, placed in shallow containers, can also be used as traps. Snails are attracted by the smell of yeast and flour, but they cannot get out.
• Containers of water with a little soap can be placed in the garden to trap snails. The soap acts as a surfactant that prevents snails from breathing and surviving in the water.

Natural Repellents

• Coffee grounds, salt, baking soda, and strong spices, such as garlic, onion, and hot peppers, can repel snails. These substances create an olfactory barrier that snails cannot tolerate.
• Some plants, such as lavender, mint, rosemary, and thyme, have natural repellent properties. You can plant these plants around your snail-sensitive plants to keep them away.

Usage Tips

• Place traps and repellents strategically, taking into account where snails are most present. Observe the behavior of snails in your garden to identify the areas where they concentrate.
• Regularly renew traps and repellents, depending on their effectiveness and weather conditions. The beer in beer traps can ferment and lose its effectiveness, and natural repellents must be renewed after rain.

The Importance of Garden Maintenance

A well-maintained garden is less likely to be infested with snails.

Waste and Debris

• Collect plant debris, dead leaves, stones, and dead wood, which can serve as shelters for snails. These dark, humid places are favorite spots for snails.
• Eliminate compost heaps that can attract snails. Compost is a source of food and moisture for snails.

Weeding

• Eliminate weeds that can harbor snails. Weeds create shady and humid areas that are conducive to snail proliferation.
• Maintain a clean and tidy garden. A well-maintained garden offers fewer hiding places for snails.

Watering

• Water in the morning to avoid excessive humidity at night, which promotes snail proliferation. Watering in the morning allows the soil to dry during the day and reduces nighttime humidity.
• Avoid watering plants directly, preferring a drip irrigation system. Drip irrigation allows you to water the roots of plants without wetting the leaves, which reduces the attractiveness of the garden to snails.

Innovative Solutions for Biological Protection

Innovative and sustainable solutions can strengthen the biological protection of your garden against snails.

Integration of Biodiversity

• Create habitats for natural predators, such as hedgehogs, frogs, and birds, by installing shelters, water points, and nesting boxes. The presence of these animals helps maintain an ecological balance in your garden.
• Promote the presence of beneficial insects, such as ground beetles, ladybug larvae, and earwigs, by planting honey flowers and avoiding the use of pesticides. These insects feed on other garden pests, such as aphids and caterpillars, and contribute to biological control against snails.

Companion Planting

• Associate repellent plants with plants susceptible to snails. For example, plant lavender, mint, or rosemary near salads and leafy greens.
• Some plants, such as rue (Ruta graveolens) and garlic, are known for their repellent properties against snails.

Cultivation Techniques

• Cultivate snail-resistant varieties, if possible. Some varieties of vegetables and fruits are naturally more resistant to snail attacks.
• Install plants in pots, which can make them less accessible to snails. Clay pots are particularly suitable because they absorb moisture from the soil and create a drier surface that is unpleasant for snails.
• Use natural mulches, such as wood chips or bark, to cover the soil and prevent snails from settling in. Mulch creates a physical barrier that prevents snails from accessing the plants.

Fertilizers and Amendments

• Use natural fertilizers, such as compost or manure, which promote plant growth and make them more resistant to snail attacks. Natural fertilizers enrich the soil and promote plant growth, making them more vigorous and less vulnerable to damage.
• Avoid chemical fertilizers that can disrupt the balance of the ecosystem and promote snail proliferation. Chemical fertilizers can alter soil conditions and create a more favorable environment for snails.

By combining these methods, you can create a healthy and sustainable garden, protected from snail attacks. Biological garden protection against snails is an environmentally friendly approach that helps preserve biodiversity and ensure a healthy and thriving garden.