Although most of us will probably never feel these slimy critters crawling across our skin, we still imagine the sensation upon seeing one.
Most of the time these small creatures are relatively harmless, that is until they either invade your home or your garden.
A single acre of farmland can hold nearly a quarter of a million slugs!
Slugs: Up Close and Personal
Many people assume that slugs and snails are both insects. However, these assumptions are wrong.
As it turns out:
Slugs and their shelled cousins are mollusks just like squids and octopuses.
To protect their delicate skin, both slugs and snails secrete a film of slimy muck which also greases the surface upon whatever they travel.
Slugs resemble very fat worms with two snail-like eyestalks.
These eyestalks allow slugs to see, but they also contain a slug's olfactory organs as well.
Under their eyestalks are two small tentacles that they use as their feelers and taste buds.
Most garden mollusks have a lifecycle of less than a year. However, depending on the species they can live up to six years.
Check out the video below:
In North America, slugs can grow up to 10 inches long.
These mollusks are hermaphrodites, meaning they possess both male and female reproductive organs.
That's not all:
One slug can lay 20 to 100 eggs a few times a year, which they put in moist, sheltered areas like underneath soil or compost.
However, you can also find them under objects on the ground like mats, rocks, logs, and other yard debris.
It gets better:
These eggs look like tiny white pearly sacks, bundled together in lovely slimy goo.
Turn over debris around your garden, and you may uncover some.
Slugs live in highly moist environments such as gardens, under containers, rocks, boards, and overgrown vegetation, to name a few places.
They sleep underground for most of the day to stay cool and come up to eat in the evening.
What slugs in your yard are chomping on
Slugs are attracted to two things: moisture and food. As for what mollusks eat, the real question is what won't they eat.
Here are a few examples of what slugs will eat:
- Dead animals
- Paper and cardboard
- Decomposing plants
- Human food and trash
- Seedlings and young plants
- Pet food
These mollusks are basically nature's slimy little garbage disposals, willing to eat virtually anything in their path.
Some slugs do have shells on the inside that are used to store minerals.
Health Dangers of Slugs
These symptoms affect both humans and pets. Plus, slugs have an infestation of parasitic lungworms, which is definitely no beuno for Fido.
It's a good idea to have your local vet give your pet a lungworm vaccine, just in case they happen to eat a slug.
However, it's perfectly safe to allow slugs to crawl across your skin (if that's your kind of thing).
Slug eggs can lay dormant in your garden soil for years and then hatch when conditions are right.
Types of Slugs
There are thousands of different slug species around the world. Some live on land while others live underwater.
As though we've not made your skin crawl enough, here are a few common types of slugs:
Slugs come in nearly all shapes, sizes, and colors.
However, they all have one thing in common:
They are just plain gross, folks.
Slugs produce a natural anesthetic through their slime, causing numbness to anything that eats them.
Slugs in Your Garden
While slugs are relatively harmless (unless eaten), the biggest threat they pose is to farmers and gardeners.
These mollusks can wreak havoc on hundreds of forms of plant life. As mentioned above, they're not exactly picky eaters.
What garden damage from slugs looks like
It's not hard to spot slug damage in your garden. That's because they often leave vegetation looking like swiss cheese.
The holes will have irregular shapes due to the slugs' file-like mouthparts.
Yum-yum, come get you some!
While they'll eat almost anything, these mollusks are said to be especially fond of these crops:
- Brussels Sprouts
- Dwarf Bean
- Potato Tubers
- Runner Bean
- Daffodil Flowers
- Sweet Pea
- Tulip Shoots
You can also tell if slugs or snails are the culprits behind garden damage if you spot slime trails.
Techniques to Stop Slugs from Invading Your Garden
Fortunately, there are a few techniques you can employ to combat the scourge of mollusks invading your garden.
Some techniques are relatively straightforward, while others require a bit more ingenuity and effort.
Determining the best way to remove and prevent slugs from destroying your garden is mostly a personal preference.
Some folks would choose to use non-lethal methods like traps, while others prefer extermination.
Check out the video below to learn more:
A slug smells with its body.
Non-lethal slug removal to help you out
For those willing to do a little extra work, non-lethal slug removal is possible.
Check this out:
This method mainly involves using traps and other techniques to remove the mollusks from your garden physically and displace them elsewhere.
Since slugs have a lousy sense of direction, you can overcome their honing instinct by moving them about 22 yards away from your home.
Non-lethal slug traps for the nice gardener
The hiding place trap is a catch and release trap that involves finding slugs hiding under objects around your yard and removing them by hand or with a small spade.
What we found:
You can then collect the mollusks in a container and release them to a safe location far away from your veggies.
The citrus trap involves leaving empty grapefruit peels (cut in half) open side down near your plants.
Slugs and other creepy crawlers will take shelter under the fruity domes, and in the morning you'll have a nice juicy citrus bowl full of slimy goodness.
Also, for traps:
You can also use objects like mats, old roof tiles, wooden boards, foil, pots, flat stones, or anything that mollusks under which slugs can hide.
A slug is able to vertically flatten its body and elongate it 20 times when it needs to enter tiny holes.
Slug traps require the following conditions:
- Cool and not hot
- Available food
Garden fabric is another excellent instrument you can use to live-trap these mollusks.
However, be warned:
There is a downside to using live-traps. Namely, you can end up attracting more slugs.
If you use live-traps make sure to clean them out daily.
If not, the dead mollusks will attract other slugs from far away.
This is because:
Slugs are also cannibals, and the dead mollusks will magically attract others from great distances.
And the same goes for other forms of bait. If you don't change your traps regularly, you'll attract more slugs.
Plus, if you use strong attractants, place your traps in places that lure slugs away from your garden.
For natural bait you can use things like:
- Cooked oatmeal
- Salad leaves
You can also purchase slug bait granules in any garden department or online.
One singular field slug has the potential to produce about 90,000 grandchildren.
Non-lethal barriers and repellants to rid your yard of slugs
If changing traps isn't your cup of tea, but you still would prefer a non-lethal solution, then your best bet would be repellants and barriers.
Since slugs travel low to the ground, they don't enjoy going over certain surfaces that irritate their skin.
You can use this to your advantage to create surface conditions that may deter them from taking a slimy stroll through your garden.
Here are a few good non-lethal barriers:
- Broken eggshells
- Broken nutshells
- Fresh coffee grounds (not instant, and the more caffeine, the better)
- Wide copper tape (however, the effectiveness is still up for debate)
- Wood ash (beware direct contact with plants)
- Grit and gravel
- Hair (yes they hate moving across hair)
- Diatomaceous earth
- Steel wool
- Pine needles
- Coarse mulch (like cedar or oak bark clippings, but not too much or you'll make a new slug habitat underneath it)
- Thorny prunings
- Crushed mint leaves
- Seaweed (slugs hate the iodine smell)
- Petroleum jelly (smear on the rim of potted plants and stems)
You can also buy slug deterrents in any gardening department or online.
Also with copper, there are several copper slug shields on the market you can try.
Slugs have the capability to reproduce by themselves, although they prefer finding a mate.
Some fit directly onto the bottom of your plants, while others sit on the ground
Find out more in the video below:
Also, with loose materials like sand and gravel, you need to apply them about three inches wide and one inch high around your valued plants. However, keep the substances from touching the plant bases.
Renew the barriers after watering or rainfall.
Use plants against those pesky slugs
Another great non-lethal option is to use plants to deter or bait these mollusks.
You can bait slugs by planting some of their favorites, like beans and strawberries, then pick them off by hand every evening.
If picking slugs doesn't strike your fancy, then try planting plants slugs hate as a deterrent.
Here are just a few non-tasty options for slugs:
- Scented Geranium
When picked up or touched, the Black Slug will contract into a hemispherical shape and begin to rock from side to side. This behavior confuses predators.
Lethal slug solutions for fast removal
If you'd rather exterminate your garden's slug invaders, then there are a few ways you can do that as well. One option is to buy slug killing chemicals, which are available in many gardening departments and online.
Here are some examples of slug killing substances you can buy:
- Ortho Bug-Geta
- Garden Safe Snail and Slug Killer
- Corry's Slug and Snail Killer
- Deadline bullets Slug Bait Killer
- Monterey Sluggo Slug and Snail Killer
Nematodes might do the trick
Nematodes are roundworms that are estimated to represent over 80 percent of the total number of multi-cellular animals on Earth. These little buggers are everywhere, in the water as well as in the ground.
As if that's not enough:
There are about 20,000 different species of nematodes identified to date.
Some nematodes, known as phasmarhabditis hermaphrodita (ph for short) are used by farmers to control slug populations.
These microscopic worms infect the slug's body through its respiratory opening. After that, it secretes bacteria which then starts to decompose the mollusks from within.
It usually takes about six to ten day for the slugs to die. However, some bigger slugs can survive the infection.
Then, after three days, the terminal mollusks stop eating.
Snails and Spanish slugs are unaffected by nematodes.
These parasites are primarily used to control field (or garden) slugs.
Nematodes are sold in pellet form. To use, mix pellets with water and apply with a watering can.
A slug’s slime absorbs water, which is why it’s nearly impossible to wash it off your hands.
Note, that you should only apply nematodes on wet, open soil, and never on lawns. If the soil isn't already wet, then it must be watered before applying the nematode solution.
Also, you must maintain the moisture in the soil daily, or the nematodes will slowly die.
This is very important:
The UV light from the sun also kills the nematodes very quickly, so it's best to apply the solution in the evening or on overcast or rainy days.
At temperatures below 50 degrees Fahrenheit the nematodes become inactive. They are most comfortable in temperatures of 54 to 77 degrees Fahrenheit.
The application of nematodes should take place between March and September.
Nematodes can also be a relatively expensive solution for a small garden, which is why farmers mostly use them.
Learn more below:
Homemade slug-killing sprays for your needs
You can also make your own homemade slug-killing concoctions.
Here are a few:
Ammonia spray is a simple solution
Ammonia is incredibly deadly to slugs and snails, however, it must be applied directly to work.
To make this spray, in a small spray bottle, combine three ounces of household ammonia with 16 ounces of water.
Go out in the evening and spray any mollusks you see on your plants.
Check back in 24 to 72 hours, and if there are still slugs sliming around your garden, make the mixture again using a 50/50 mix for more oomph.
However, be warned:
Ammonia can injure sensitive plants, so you may want to test it first on a small leaf and gauge the reaction.
But, ammonia can also benefit plants because it turns into nitrogen that plants can use for food.
Slug blood is green.
Garlic sprays: Smelly but effective
Galic spray causes slugs to secrete excess mucus. Over time, the mucus overproduction causes slugs to dry out, shrivel up, then die.
Follow these steps to these steps to make garlic spray:
- Soak four cloves of minced garlic in one tablespoon of mineral oil for at least 24 hours
- Strain the solution in a spray bottle
- Pour in one pint of water
- Add a teaspoon of liquid dish soap
- Store it in the refrigerator until you're ready to use it
- In the evening, go out and find some slugs to terminate
- Repeat every 24 to 72 hours until the slugs are gone
Note, that you'll need to reapply this solution after watering or rain, as the water will wash the solution off the plants.
Check out the video below:
Use caution when mixing or using these mixtures as direct contact can irritate sensitive skin and eyes. It's best to keep children and small pets away from areas treated with these solutions. Be sure to wear waterproof gloves, long sleeves, goggles, and a face mask when applying or mixing these solutions.
Salt and salt water could work as well
Salt is perhaps the most common substance people use to kill slugs.
Just a sprinkle of salt on a slug or snail is fatal.
Unlike regular salt, Epsom salt is a great weapon to use against your slug invaders.
When starting your garden you can mix in one cup per 100 square feet into the soil before you plant.
You can also put some Epson salt in a spray bottle with water for a killer spray or just sprinkle some granules around your garden.
Best of all:
Epson doesn't harm your plants, in fact, it actually improves the health of your garden by helping increase nutrient absorption.
Watch the video below:
Lethal traps to kill those annoying pests
Here are a few deadly traps you can set that will kill and trap slugs.
Beer traps are a thing
These are traps that use beer as a lure.
Follows these steps to make a beer trap:
- Using an empty plastic bottle, bag, or any small container with a small opening, fill it a quarter to half full with beer
- Set the traps out (slightly buried with the opening at an inch above ground level works best)
- The slugs are drawn to the fermented yeast (not alcohol)
- They enter the container, fall into the beer, and eventually drown
- Collect the trap in the morning
Using a container such as a bowl or one with a large opening may be less effective, as the slimebags will most likely just dip in, take a few sips and go home.
The small opening makes it harder for them to escape.
Note once again, it's essential to collect the traps every morning, lest you lure more of these nasties to your property.
Liquid-traps could help too
These traps work the same way as beer traps, except you can use 100 percent grape juice or combine two teaspoons of baking yeast and eight ounces of water to make the solution.
The Enemies of Your Enemy: Attracting Predators Who Eat Slugs
If you don't want to put effort into creating and maintaining non-lethal traps and barriers, nor want to kill the slugs directly, there is another solution.
You can hire a local contract slug-killer to do the job for you.
Check this out:
Here's a list of a few slug-eating predators:
- Ground beetles
- Horn Flies
That's not all:
Here are a few ways to entice natural predators to hang out in your garden:
- Plant as many indigenous plants and trees as you can
- Provide wild corners in your garden and leave them be
- Create some garden ponds with rich bank planting
- Layer piles of stones with many cavities
- Build dry stone structures (dry stack stone walls) in your garden's sunny spots
- Pile up leaves in undisturbed isolated spots
- Create blooming hedges with native plants or dead hedges
- Minimize garden lighting and where necessary use only warm-white LEDs
- Do not clean the beds in autumn and leave plant stems until next spring
- Leave deadwood and use different types of coarse woody debris
- If possible, try not to dig up the soil; just open the surface a bit and loosen the subsoil
- Offer small open sandy areas with an open water source nearby
- Mow lawn rarely to promote a more insect friendly environment
- Refrain from using chemical crop pesticides
Note that many of these suggestions may be too extreme for many gardeners.
However, if you want to attract more natural predators, incorporating a few of these methods should work.
Toads are one of your best allies against these little slimeballs, so setting up a few little natural ponds and other practices will promote toad activity and benefit your garden.
Here's a great video with more tips for attracting toads:
Make Your Garden More Inhospitable for Slugs
"Slug sex is a marvel to behold. Two hermaphrodite slugs meet on a tree branch and secrete a thick rope of extra-viscous slime, down which they gyrate like pole-dancers.
Each inflates a huge, pale, flower-shaped penis, which they entwine together, and each slug fertilizes the other. All this while dangling in mid-air."
Along with some of the other techniques that either trap, deter, or destroy slugs, making your garden inhospitable to slime crawlers is another crucial tactic.
Since these mollusks enjoy hiding under objects, you may want to remove things like stones, rocks, logs, branches, mats, or anything they could seek shelter under.
Extra mulch is another slug hiding spot you can eliminate.
Furthermore, you can also use stands under your plant containers to raise them off the ground, taking away another favorite slug hiding spot.
Now here's the bad news:
Unfortunately, there's no permanent solution for getting rid of these little snot surfers, like many other garden pests. Keeping them under control takes vigilance and patience.
However, by using some of these techniques, you'll win a lot more battles against your garden nemesis. Good luck and happy gardening.
Georgia has graduated from a nutrition expert degree and her work involves some freelance blogging on the side of her main part time job in a doctor’s office. She doesn’t travel a lot due to work constraints, but she likes going out as often as she can to compensate.