How to Protect Your Garden from Slugs and Snails

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15. Plant marigolds – but away from your garden

Marigolds are a mainstay in the world of natural pest control methods; however, we are usually planting them near our gardens to ward off a variety of pests. Snails are actually attracted to marigolds, so if snails are the problem you are trying to fix, you will need to plant your marigolds away from your garden, rather than near it.

6. Put Used Coffee Grounds to Work

Unlike some of us, slugs really do not like the smell of ground coffee. Can you imagine? Scatter it around plants they flock to; use it alone or mixed with the eggshells. Coffee grounds will also decompose and make your plants happy.

A few more tips on how to get rid of slugs in the garden

In addition to these “power 8” ways to get rid of slugs in the garden naturally, there are a few other tricks you can try, though their effectiveness is debatable.

Diatomaceous earth has long been touted as a great slug control. It’s a fine powder that is very sharp microscopically and the edges easily cut through slug skin and desiccate them as they crawl over it. The trouble is that as soon as diatomaceous earth gets wet, it’s rendered useless. I don’t know many gardeners who have time to make a circle of dust around every plant and then replenish it after every rain or heavy dew. • A hearty sprinkle of salt, placed directly on a slug’s body, may desiccate it enough to lead to its death, but there’s a good chance the slug will simply shed its slime layer along with the salt and carry on as usual. I’ve seen it happen so many times that I put aside my salt shaker long ago. • And lastly, sharp-edged items, such as sweet gum seed pods, crushed eggshells, and dried coffee grounds have all been touted as great slug deterrents. I respectfully disagree and so do several studies.

Our online course Organic Pest Control for the Vegetable Garden, provides even more information about managing slugs and other pests naturally in a series of videos that total 2 hours and 30 minutes of learning time.

2. Stop using pesticides on your lawn

Firefly larvae are one of the most prevalent predators of newly hatched slugs, and putting synthetic pesticides on your lawn doesn’t just kill the “bad” bugs, it also kills beneficial insects, such as fireflies, that live in the lawn and help you control pests like slugs. Instead, switch to organic lawn care techniques and let these good bugs help you control slugs naturally.

Do You Really Have a Slug Problem?

Slugs and snails get a bad rap. Most people who find holes in leaves will blame them for the damage when in fact many other critters can produce the same type of damage. If you don’t see a slime trail on new damage, it is probably not a slug.

Take the time to get a proper ID. There is no point in treating for slugs if you don’t have a slug problem. This video gives you more detail: 

4. Add copper

When snails touch copper, their slime reacts in a way that they receive an uncomfortable electrical shock that will quickly encourage them to turn around and find somewhere else to dine. Adhesive copper tape is available at home improvement stores, garden centers, or online and is the most convenient way to ward off slugs and snails with copper. If you go the adhesive copper tape route, you can simply run the tape along the edges of your garden beds to keep snails from entering.

If you do not want to purchase copper tape or just happen to have a jar of copper pennies lying around, you can also use pennies to protect your garden. When using pennies, you can glue them to your garden bed to keep them in place and will want to make sure they are very close together so you do not leave pathways for smaller snails and slugs to sneak through.

Biological Controls

For combating gastropods, my personal weapon of choice is beneficial nematodes.

One hundred percent natural, nematodes are naturally occurring microscopic worms that are mixed with water for application.

The best times to apply nematodes are once soil temperatures have warmed up in spring, and after intense summer heat has ebbed in late summer/early fall.

They won’t kill adult snails or slugs, but when applied to the soil, nematodes enter the gastropods’ eggs. They then release bacteria that kills the eggs, then feed off the eggs and reproduce before moving on – with an effective killing rate of about 90 percent.

People, birds, pets, and helpful insects such as bees, ladybugs, and earthworms are completely resistant to these hardworking microbes.

Nematodes move swiftly through pre-moistened soil, and can be applied with a hose and sprayer or with a watering can for smaller areas.

You won’t see immediate results with nematodes, but the following year you’ll notice a significant reduction in the slimy herbivores.

For best results, make three consecutive applications – spring/fall/spring, or fall/spring/fall. After that, an application once every 18 months will keep gastropod numbers at bay.

Timing is important with this method. A package contains millions of live nematodes, and if you don’t plan on using them immediately, they need to stay refrigerated until application. In the package, they have a limited shelf life of around two weeks.

Nematodes can be purchased online through various retailers. There are different species of nematodes, so be sure that the ones that you buy are listed for slug and snail control.

Before purchasing them, ensure soil temperatures are adequate, and that you’ll have the necessary time available for application.

Read our complete guide to doing battle against creepy crawlies with nematodes here.

11. Use Companion Plants

Strategically placing complimentary plants together is one of the best things ever; Mother Nature is a genius, so why not let her help? You can place sacrificial companion plants that slugs love near your precious plants to lure them away from the plants you want to save for yourself.

Hand Picking Works

Hand picking slugs and snails works, but I don’t think too many of us do this.

Water the area in late afternoon. Then hunt them a few hours after sunset using a light.  Dump any you find in soapy water to kill them.

Weeding after a rain or early in the morning when dew is still on plants, also works. If I find a snail, I just step on it and feed the birds.

Are slugs useful for anything?

It might seem tempting to napalm the slug population after they’ve eaten your strawberries, but slugs aren’t all bad! In fact, a healthy (but well managed!) slug population is good for the garden. Slugs break down garden debris and turn it into nitrogen-rich fertilizer that enhances soil nutrition (similar to worm composting). They also are a natural food source for many beneficial insects, birds, frogs, snakes, and toads.

4 Cheap Ways to Naturally Get Rid of Slugs

Okay, you tried preventative methods, and now you’re ready to get rid of slugs in your garden without the use of synthetic pesticides. Good news! There are a ton of ways to use traps and baits to reduce the slug population in your garden.

Manually Removing Slugs

As we’ve already talked about, slugs aren’t all bad! If you have a small infestation, just head out after dusk with a headlamp and pick those suckers off your plants. Drop them into a bucket of soapy water to kill them immediately, or move them to an area where birds and snakes can eat them—and the circle of life continues!

Plant Trap Crops

Planting trap crops is easily our favorite way to get rid of slugs and many other common garden pests. The gist is this: plant a crop that the slugs REALLY love to enjoy, they choose that plant from the garden buffet, and then you can sacrifice those plants and concentrate your slug removal methods there.

In general, slugs like to eat the tender leaves and shoots of new seedlings, but some plants are irresistible to slugs at any stage of growth. Slugs absolutely love to eat marigolds and basil. A robust border of either (or both) around your garden can go a long way to draw out slugs from your tender seedlings.

Beer Traps to Bait Slugs

Beer Traps to Bait Slugs

The most common piece of advice you’ll get when dealing with slugs is to put out beer traps. Beer traps are easy and cheap to make, and the traps work well because slugs are attracted to the scent of the yeast in the beer. However, we don’t recommend them as a first line of defense. These traps do drown and kill slugs, but they frequently also kill beneficial insects, so we recommend only going this route if you are dealing with an overwhelming infestation.

To make a beer trap, simply take a clean, shallow container (a cleaned-out tuna can, small yogurt container, or butter tub all work really well), and bury it in the ground with about an inch sticking up out of the soil. Fill the can with beer—any beer works, but slugs tend to really like the yeasty smell of darker beers—and then wait for the slugs to crawl in and meet their demise.

Growfully Protip

Empty and refill your beer traps regularly. Slugs are not as attracted to stale beer as they are freshly-poured.

For beer traps to be successful, you need to place them about every 3 feet—which can become quite costly and labor-intensive for larger growing spaces.

Grapefruit Traps to Get Rid of Slugs

Grapefruit (and other citrus fruit) traps are live traps that are less deadly to beneficial insects than beer traps. Enjoy yourself a half of a grapefruit—scooping out the flesh inside. Then place the empty grapefruit half upside down in your garden. Overnight, slugs will be attracted to the sweet scent and take cover in these citrus domes, and in the morning, you can remove the grapefruit half, take it far away from the garden, and feed the birds!

Growfully Protip

Half a hollowed-out cantaloupe and an orange rind also work well for the grapefruit trap method. Some folks also use upside-down flowerpots or bowls to achieve a similar trap.

Bait and Trap

A good point to remember is that to bait gastropods is to attract them – so keep bait and traps a safe distance from any plants you want to protect.

The Beer Dish Trap Simply fill a shallow container with beer and sink it into the soil, then leave overnight. Slugs and snails are attracted to beer, glide over for a sip, then drown in it. Remove the corpses in the morning, and refresh with their favorite suds! Esschert Design Ceramic Slug Trap available on Amazon Containers can be as simple as a plastic deli dish, or you can opt for something a bit more decorative – like this cute ceramic snail. Hidey-Hole Trap Create a welcoming environment for slugs and snails to hide under in the daytime with any flat object, or anything that makes a nice gastropod den.

A piece of plywood, thick dark plastic, pot saucers, overturned containers, or anything that will provide cool shade will work. The rinds of citrus (like oranges and grapefruit) and melon halves make an alluring den for them as well.

Water the area first, lay down the trap material, bait with a piece of leaf lettuce if needed, and return in a day or two to remove and destroy the crawly critters.

3. Build a Sharp Barrier

A slug’s Achilles ankle is its soft body, easily irritated by sharp or dry materials. Use this to your advantage by sprinkling wood ashes, diatomaceous earth, gravel, or lava rock in a wide band around individual plants—or the entire garden—to discourage slugs, as they won’t want to crawl across the bumpy barrier. Wood ashes have the bonus benefit of adding potassium to your soil and raising the pH, so consider choosing that method as your first line of defense.


I’m so board

A board on the ground in a shady spot might not look like much to you, but to slugs, it looks like a great place to spend the day. Tuck a 1- or 2-ft.-long piece of board under plants to create a moist, shady hiding place that’ll attract lots of slugs. Slugs are active at night, but during hot days, they retreat under mulch, rocks…or board traps. Check the trap in the afternoon, when slugs are enjoying their siesta under your board.

Once you’ve coaxed slugs away from your plants, you don’t want them sneaking back on to tender leaves the minute your back is turned. These easy barriers will keep the pests at a distance.

Diatoms to the rescue

Diatoms to the rescue

Yes, I said diatoms. Diatomaceous earth, a white powdery substance, is made up of the crushed shells of fossilized diatoms, tiny hard-shelled algaelike plants. What does that have to do with slugs? Well, diatomaceous earth is abrasive. It creates tiny cuts in the soft underbellies of slugs and snails, causing them to dry out and die — no more holes in the hostas!

Lightly sprinkle diatomaceous earth under the drip

Lightly sprinkle diatomaceous earth under the dripline of hostas and other shade plants, just like you’d put cinnamon sugar on toast. Make sure you completely surround the plant with a 5- or 6-in.- wide band of diatomaceous earth. You’ll need to reapply it after rain, because it washes into the soil. Be careful when you apply it, though — you don’t want those tiny abrasive particles in your lungs, so be sure to wear a dust mask and gloves.

There you have it. These four easy-to-use methods will keep slugs (as well as their better-protected relatives, snails) from doing their worst to your prized plants. And you won’t have to worry about storing poisonous slug bait in the garden shed, either!


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