…blog by Nikki Banfield, Buglife Communications Officer. Originally written for Ark Wildlife in March 2023
When I was asked to write a blog post about an invertebrate that is good for gardens, I quickly thought of a bunch of species that pretty much spoke for themselves, like butterflies, bees, ladybugs, and worms. Beautiful, liked, and interesting animals that most of us are glad to have in our gardens and will often go out of their way to help. They look good, they have positive personas, their “usefulness” is clear and apparent.
However, my grey matter kept whirring. I didn’t want to “settle” for what was simple and clear, so I kept going. Where I ended up was a little slimier and had more tentacles, among the garden “pests.”
Slugs and snails. They might not seem like the most obvious choice, and I can hear a lot of people yelling at their computers. I can feel their disappointment in their heads, but I love an underdog and will always be on their side. They have a special place in my heart and I’ve always found them fascinating.
Slugs and snails get a bad rap; they’re often harmed and misunderstood, but like all living things, big and small, they are an important part of many ecosystems.
To get back to basics, a “slug” is a common name for a land snail that doesn’t seem to have a shell. They are often called “snails without shells.” Both descriptions are in some part right, but also in some part wrong.
Slugs are closely related to snails, but are more akin to cousins than siblings. Some scientists think that slugs evolved from snails through a process called vitrinization. During this process, the snail’s shell has either shrunk and disappeared or been absorbed into the body, allowing it to survive without an outer shell.
About 40 species of slugs live in the UK right now, and most of them are native. But did you know that three of those species are “shelled-slugs”?
What most people think they know about slugs is wrong about shelled-slugs because they have external shells! The shell may be small, but what’s left at the end of the slug’s tail is a small piece of what it used to be.
Snails often get a bad rap from gardeners. With their voracious appetites and ability to decimate vegetable patches and ornamentals seemingly overnight, it’s no wonder we view them as pests. But what if I told you snails can actually be beneficial in your garden when managed properly? Here’s an overview of some surprising advantages snails can offer:
They Contribute to Soil Health
Unlike slugs, snails are primarily decomposers that feed on dead leaves, flowers, and decaying plant matter. This speeds up the recycling of nutrients back into the soil. Their nitrogen-rich feces acts as a natural fertilizer for plants. In fact, snails are responsible for 33% of organic matter decomposition in the garden – almost as much as earthworms! Their tunneling and feeding activity also helps aerate soil.
A snail processes waste far faster than bacterial decomposition alone. Their poop releases nutrients much quicker than waiting for microbes to break down mulch and compost. So while they nibble on decaying matter, they rapidly convert it into readily available plant food.
They Indicate Ecosystem Health
Snail populations thrive in balanced, biodiverse habitats like woodlands and prairies. But they decline in frequently tilled soils and agricultural areas where pesticides are used So snails can act as bio-indicators of environmental health If your garden has a robust snail community, it’s a sign you have rich, natural soil and a thriving ecosystem.
Scientists even use snails to monitor pollution levels. Because they absorb materials from their environment, analyzing snail tissue informs researchers about the presence of heavy metals and chemicals. A high snail population demonstrates your garden is low in toxins.
They Provide Food for Wildlife
While baby snails emerging in spring can decimate seedlings, they in turn become a vital food source for birds, reptiles, amphibians, and beneficial insects. So if you take a broader view of your backyard ecosystem, snails help support predator species.
Ground beetles, fireflies, toads, and decollate snails all consume significant numbers of juvenile snails. Developing frogs and lizards thrive when snail populations boom. And songbirds relish escorting chicks around to gorge on these soft-bodied invertebrates. Look at snails as a live food producer contributing to wildlife diversity.
They Clean Up Garden Litter
Most snails and slugs prefer to eat decaying plant matter and fungal growth rather than live vegetation. So they help clean up decomposing debris, paring down leftover mulch and cleared stalks. This keeps the garden looking tidy.
Snails graze on algae, lichens, and fungi that develop on stone surfaces, keeping patios and borders free of slippery green growth. They nibble away diseased and withering leaves affected by blight or mildew before it spreads. A snail serves as free garden cleanup crew!
They Add Organic Matter to Soil
Through their feces, snails introduce partly decomposed matter into the soil, improving texture and water retention. As they consume fungi and microorganisms along with plant material, their poop contains an array of nutrients and microbiome diversity.
Snails buried in loose soil or leaf litter work organic particles deeper into the ground. Their mucous secretions help bind minerals to clay and humus particles, reducing leaching. And as they move through their habitat, snails aerate and churn the earth.
They Provide Raw Material for Compost
Snails collected through traps and handpicking can be composted along with their eggs and dropped shells. Their bodies contain calcium and other minerals derived from what they consume. When added to a worm bin or compost pile, snails accelerate decomposition of garden waste.
A snail compost additive also inoculates the mix with native microbes and fungi from your specific area. As the snail bodies break down, they release nutrients to create a rich, natural fertilizer perfect for your plants.
They Pollinate Plants
Though small and slow moving, snails do aid in transferring pollen between flowers as they travel through vegetation. Their sticky foot picks up and transports grains, inadvertently cross-pollinating some plants. Though bees remain the champions, snails lend a helping hand.
Certain snail species also disseminate seeds as they traverse the garden. By transporting and burying seeds in their mucous, snails help regenerate plant populations and disperse native species.
They Control Pest Populations
While young snails can severely damage seedlings, mature snails prey on other problematic garden pests. They devour aphids, mites, thrips, cabbage worms, cucumber beetles, and greenfly larvae. Releasing some snails in your greenhouse or on infested plants helps reduce these crop-damaging insects.
Several snail species also feed on weed plants like bindweed, dandelions, plantain, and thistles. They gnaw on invasive plants and saplings, regulating their spread. A managed snail population keeps pest numbers in check naturally.
They Provide Nutrition for Human Consumption
In many cultures, snails are collected for food. Their meat offers a lean protein source low in fat but high in iron, magnesium, potassium, selenium and zinc. Snail caviar and eggs are especially nutritious. Farming edible snails provides sustenance while controlling their numbers.
Some hobbyists grow delicacy snail breeds that don’t damage garden plants. Allowing these non-invasive varieties to feed on compost and mulch produces premium escargot. You get pest control plus gourmet ingredients!
How To Manage Snails for Maximum Benefit
Follow these tips to take advantage of snails’ positive contributions:
-
Remove excess debris, diseased leaves, and heavy mulch that attract snails.
-
Handpick large snails after rain and drop in soapy water.
-
Use copper tape as barriers to protect seedlings and vulnerable plants.
-
Trap clusters under boards to remove for compost.
-
Release decollate snails to prey on eggs and small snails.
-
Create a designated snail composting area in a corner of your garden.
-
Grow sacrificial bait plants like cabbage to divert snails from crops.
-
Check potted plants and lift pots to handpick snails beneath.
-
Use snail fences made of grit or diatomaceous earth around beds.
-
Encourage predator beetles, lizards, and birds by providing habitat.
-
For heavy infestations, use iron phosphate bait judiciously.
A snail-friendly, balanced garden minimizes damage while utilizing snails’ positive impacts. Seek natural ways to manage their consumption and fertility cycles. With some effort to limit their damage, you can gain valuable soil enrichment, pest control, wildlife food sources, and compost materials from snails. A few simple precautions allow these intriguing garden allies to do more good than harm.
Slugs and snails are natures clean-up crews and recyclers.
As they move around in the dark, they eat garden waste, fungi, and rotting plants, which powers their metabolism. They have also been observed feeding on the excrement and carcases of other animals. So, they are very important to the decomposition process. Their burrowing, feces, dead bodies, and shells help to recycle and move nutrients into and through the soil. It’s also thought that they aid in fungal spore dispersal, thanks to their diet too.
Additionally their shells can form an important source of calcium for other creatures in calcium-poor habitats.
Slugs with a home?
In contrast, “snail” is the common name for terrestrial gastropods that have shells. A snail’s shell starts out soft and grows harder as it grows. This is because snails eat calcium. The snail’s shell protects and houses many of its vital organs, such as its liver, lung (yes, they only have one), kidneys, and heart. When a snail loses its shell, it doesn’t “turn into a slug,” it just dies. ☹.
Different types of snails have different-sized shells. Some are big enough for the snail to hide in and stay safe, while others aren’t big enough for their bodies. This type of slug doesn’t have a shell that is small enough for it to retract into, but it also doesn’t have a shell that is just there for show like shelled-slugs do.
To make things even more confusing, the shell of some semi-slugs might not be visible at first glance because the mantle (the slightly ridged area at the head end, behind the tentacles) might cover it. This would make it look like an internal shell.
There are around 120 species of snail found in the UK.
The Surprising Benefits of Snails in Your Garden
FAQ
Is it good to have snails in your garden?
What are the advantages of snails?
Why do I have so many snails in my garden?
Do snails have a purpose?
Are slugs and snails good for your garden?
Slugs and snails can be a mixed blessing in your garden. Slugs are almost exclusively a nuisance, while snails can have some benefits. Generally speaking, however, the drawbacks of each outweigh the benefits, so keeping them under control is key to maintaining a healthy garden.
Are snails good for plants?
Yes, snails can be good for plants in moderation. They help break down decomposing organic material, contributing to soil health. However, they can also harm plants by eating leaves, stems, and flowers, especially in large numbers. Therefore, it’s important to maintain a balance.
What do garden snails eat?
Garden snails are known to feed on a wide range of plants, including vegetables, fruits, flowers, and ornamental plants. They are especially attracted to plants that are moist and tender, such as seedlings and young plants. Snails use their radula, a ribbon-like structure with rows of tiny teeth, to scrape and chew the leaves of plants.
Do snails kill plants?
This can be a problem for gardeners, as snails can quickly damage or even kill plants. However, some species of snails, such as the decollate snail, are predators of other snails and slugs, which can be beneficial to the garden. Snails produce nitrogen and nutrient-rich feces, which can help nourish the soil. So, are snails good for plants?