If you live near any coastline, then you probably associate snails with the beach. They are commonly found stuck on damp rocks at the beach, especially during low tide.
However, these are just sea snails, and make up a small number of the thousands of different types of snails. There are many aquatic snails, both salt water and fresh water types, and a variety of land snails.
In fact, one of the more common types of land snails are known as garden snails, and you probably have some living near your outdoor plants. They are an important part of the ecosystem, and help to break down fallen leaves and other forest debris.
But are snails good for the garden? In this article, I’ll go over the benefits and the drawbacks of having snails in your vegetable garden space, and what you can do about an infestation.
Skip ahead:
- About snails
- Benefits
- Why snails are bad
- Dangers of snails in the garden
- How to get rid of snails
- Other garden pests
About Snails
Snails, along with slugs, are gastropods. This group of animals contains thousands of species, and comes from the same phylum as octopuses, squids, and clams. Snails have adapted to live in salt water, fresh water, and on land.
You are likely to see a variety of land snails in the garden. Here in New England, we have the squat, saucer-shaped Euchemotrema fraternum, the more rotund Neohelix albolabris.
To illustrate the wide variety of snails, take a look at the world’s largest land snail, an African giant type. It weighed about 2lbs and spanned well over 1 foot in length.
What do snails eat? Garden snails feed primarily on decaying organic matter, such as fallen leaves, fungi, lichens, worms, insects and even other snails. However, they also have an appetite for living plants, especially when dead matter is in short supply.
When are snails active? Snails usually feed at night. However, you can find them feeding during the day on particularly rainy and overcast days, or after a heavy rainfall.
How Are Snails Good For The Garden?
In some ways, snails can actually benefit the garden. They are good at cleaning up the garden, consuming dead foliage, insects, mushrooms, and more.
Snails and slugs also break down their food through digestion. As a result, their waste acts as a nutrient supply, effectively fertilizing the garden soil. This is true of most garden critters, as they help release simple elements from the compounds in organic matter.
However, this is pretty much where the benefits end.
How Are Snails Bad For The Garden?
While snails can provide some benefits to the garden, in most cases they are considered pests. Snails usually prefer to eat decaying matter, but they will often resort to fresh foliage in a garden setting, especially when populations are high.
If snails are in your garden, you are likely to find irregularly shaped holes in your leaves with jagged edges. These holes are often randomly scattered across plants.
This can be especially risky in early spring when you first put out your seedlings. In a single night, snails can devour many of your precious young garden plants.
Which garden plants do snails eat? Snails will happily feed on the foliage of strawberries, peppers, tomatoes, cabbages, lettuces, basil, hostas, and many other edible and ornamental plants. There are, however, some plants that show some resistance to snails and slugs, such as hydrangea, ferns, and lavender.
How Snails Can Be Dangerous In The Garden?
As if you didn’t need another reason to dislike snails in your garden, they can also be dangerous. Slugs and snails are a vector for a dangerous disease called angiostrongylyasis, or rat lungworm disease.
The disease is caused by a worm, Angiostrongylus costaricensis, that commonly inhabits slugs, snails and rats. The lifecycle is pretty gross, but suffice it to say that snails and slugs may have these worms in them.
These worms can also infect humans, and can be damaging to the brain and central nervous system. If you touch a snail in the garden, or your produce have had infected snails on them, it can be a risk to your health.
How to prevent angiostrongylyasis
While it is impossible to get rid of all of the snails in your garden, there are some ways of minimizing your risk of disease.
- Practice good hygiene in the garden. There are many reasons to be cleanly in the garden, and snails and slugs is just another. Always wash your hands thoroughly before and after tending to your plants.
- Deter, trap, or kill slugs. There are many effective methods of reducing snail populations in the garden (see below). If you notice holes in the foliage, especially in the early morning, start working to get rid of garden snails right away.
- Wash produce thoroughly. Whenever you harvest food from your garden, be sure to wash it thoroughly under cool water. While you’re at it, check the tops and bottoms for slugs or snails.
- Cook food to 165°F. Boiling your food for 5 minutes or longer, or bringing food to 165°F for 10 minutes will kill off any worms that may be present.
Most cases of rat lungworm have been in China and the Pacific islands, but some cases have been reported in parts of Hawaii. In my opinion, it is better to be safe than sorry and control snails in the garden.
How To Get Rid Of Snails In The Garden
Now that you know that snails are more of a pest than a friend in the garden, let’s discuss how to get rid of them. There are several options, and internet gardeners make many claims about how to trap and kill snails and slugs. Many myths have been busted (like using eggshells and coffee grounds), but here are a few options that work well.
- Use snail and slug bait. There are many products available that will attract and kill snails and slugs in the garden. These products will usually contain iron phosphate and are effective at controlling slugs and snails. However, be sure to use the product as directed, and always put the bait in an enclosed trap to prevent other wildlife from eating it.
- Welcome natural predators. Snakes, toads and frogs eat slugs and snails. Not everyone can tolerate snakes, but try your best to allow them to help your garden. Some gardeners provide a shelter for toads to encourage them to stick around and keep garden snails in check.
- Don’t clean up so much. As we covered, snails eat decaying matter, such as fallen flowers, leaves, branches, and fruits. So instead of keeping the vegetable garden perfectly tidy, toss picked flowers, rotted fruits, and other dead matter to the edge of the garden for the snails and slugs.
- Hand pick them. Hand-picking snails and slugs can be effective, but it is not a favorite method. For one, they are usually only out at night, meaning you’ll have to pick them off in the dark. Also, it is not everyone’s favorite job. If you do try it, always wear gloves, and toss the snails into soapy water to kill them. Wash your hands thoroughly, and repeat every night.
Again, there are a multitude of suggested methods of dealing with garden snails that have been shown to work poorly. These include using salt as a deterrent (bad for the soil), using copper tape (only slightly deters snails and slugs), and using beer traps (most don’t end up getting caught).
Another common idea is using diatomaceous earth, which works, but only when it is dry. Once it rains, the DE is rendered ineffective against all bugs. Finally, I have seen suggestions for using ammonia as a snail and slug repellant. This can kill snails, but it also evaporates quickly and can be harmful if inhaled – not suggested!
So, stick to the bulleted suggestions above and use the methods that have been proven to work. If you approach them correctly, snails in the garden don’t have to ruin your harvests!
Other Garden Pests
If you have snails in your garden, it is likely you will see a number of other potentially problematic pests. Here is a short list of some pesky bugs to look out for.
- Aphids. Small, round-bodied insects that feed on the sap of your plants. They can multiply incredibly fast, and are best dealt with in early spring. Natural predators include lacewings, ladybugs, praying mantises, and many more insects. Use an insecticidal soap for severe or indoor infestations.
- Ants. Ants are common in the garden, and will actually protect aphids if they are present. However, ants usually won’t harm your garden plants directly. Deal with the source problem (usually another pest) to reduce ant populations.
- Caterpillars. If you have enough of them, caterpillars can be bad for the garden. Some of them are known to devour impressive amounts of foliage in just a few days. However, not all are problematic (and they turn into beautiful butterflies). Assess the damage they may be inflicting before deciding whether to remove to leave them be.
- Beetles. Not all beetles are bad, but some are. If you see a beetle on your garden plants, try to identify it before deciding to take action. Even the dreaded Japanese beetles have their predators, including birds, racoons, and skunks.
- Spiders. While you may not like spiders, they are actually a good thing in any garden. They come to eat insects, not plants. Spiders help keep pest populations in check, so next time you see a spider in the garden, be its friend!
There are countless insects and animals you may encounter in your garden, regardless of where you live. In many cases, the best course of action is to allow nature to take care of the issue on its own. Spraying chemicals usually ends with a worse problem, so invite all walks of life to the garden and it will balance naturally.
I hope this article helped you determine what to do about snails in the garden. Yes, they can be a pest, but they can also help clean up the plant waste and nourish the soil if dealt with properly.