Bug Bio! Snails and Slugs

Learn how to spot snail and slug damage and strategies for organic pest control

Slugs and snails can cause problems in the garden eating holes in leaves, stems, flowers, tubers, and bulbs virtually overnight. They can cause damage throughout the year on a wide range of plants, but seedlings and new growth on herbaceous plants in spring are most at risk. As mostly nocturnal creatures, it can also be tricky to spot them in the act, but here are a few key tips for managing a slug or snail infestation in your garden.

What does Snail or Slug Damage Look Like?

Snails and slugs typically behave in similar ways and attack similar plants, so learning how to manage one pest will help you manage both effectively. Their signs of damage are also very similar to one another as well.

Look for random, irregular holes in the leaves. These will be scattered around the surface of the leaves or flower petals and not just on the edges. Sometimes the holes will appear entirely within the leaf or flower and not on the edges at all.

Snail eating a leaf, the holes all around it are examples of common snail damage

Another example of snail or slug damage on hosta leaves

Another type of snail or slug damage goes one step further. This is where the pests have found something particularly tasty and they eat it right down to the skeleton. This is very common with broccoli, cauliflower, and other members of the mustard family of plants. It's a frequent heartbreak in the fall when you plant all of your garden veggies only to return the next day and find them eaten down to the skeleton. What's left will look like just the stems, no leaves, and lots of slimy edges. If you've ever had this happen, chances are you were thwarted by these guys. In order to save yourself this misery, I suggest doing a preemptive snail and slug hunt BEFORE you plant your fall garden but after you've pulled out your summer plants.

Here's an example of this type of damage.

Snail or slug damage that has eaten the broccoli right down to the stems

What do snail eggs look like?

You may also locate clutches of snail eggs in your garden. They are typically laid in a pile and look like little slimy white pearls. I have found them in shallow pits underneath old planter pots, often guarded by one or both adult snails.

Snail eggs

How do I find where they're coming from?

One of the telltale signs that you're dealing with these animals is the slime trail that they leave behind. You may see it glistening across the soil or snaking along the damaged leaves, but you may not notice it either. So, whether you see the trails or not, it's time to do some snail hunting.

First, look around the area that's nearest the damaged plants. Are there any overgrown plants, turned over plant pots, or wood panels nearby where the snails could hide out during the day? If there are, you may be able to find your snails and slugs hiding inside them with a bit of detective work. Snails prefer cool, moist, and dark environments to hide away from the heat of the day, so I often find them stuck inside discarded plant pots or on the side of my raised beds that's facing tall grass.

Once you find them, it's time to evict them from your garden.

An example of a shimmering snail trail left behind. Sometimes they are easy to spot, but sometimes they aren't. You may still be dealing with snails even if you don't spot their trails.

How do I get rid of the snails and slugs organically?

In an edible garden I always prioritize trying minimalist approaches to pest management before jumping to more invasive methods. This means starting simple and working your way up the ladder to more intensive methods. It's also known as integrated pest management or IPM, the idea is to tread lightly as you attempt to bring balance to your local ecosystem, recognizing that your efforts can be disruptive to creatures up and down the food chain. Doing a combination of strategies from level one is what I do any time I see snail damage start to creep up around the garden and I rarely need to use any other methods.

Level 1 Options (Start with a combination of these!)

Hunt for snails at night

Slimy, slithering snails and slugs prefer to move around in the cooler, moist evenings. You can take advantage of this fact as a keen gardener and wait to make your move until nightfall. Go out with a flashlight and a bucket to round them up just like our grandfathers did back in the day. Bring the kids along too, they're excellent snail hunters! Snails and slugs are easy to spot because the flashlight will make their trails shine. After a couple of nights hunting like this, you'll see a huge drop in immediate snail damage. You may find that this one strategy is all you need to do to keep snail populations in check.

A collection of snails we gathered one night with the kids

Clean up around the garden

Snails, being slow creatures, don't like to travel vast distances to eat. So if you're seeing damage, then you know that they're hiding somewhere close by. Now is the time to clean up the space around your plants. Cut back overgrown spots that could provide permanent shade or moisture for snails to shelter in during the day. Remove old materials, pots, and debris. The idea is to make their commute to your garden so long that they decide to look elsewhere.

Set out a "trap board" or two or three

Another way you can take advantage of snails' hiding in the day is by providing them a place to hide. Set out an old wooden board, fence piece, piece of scrap wood, etc. propped up slightly so they can get underneath it close to the source of your damaged plants. At night the snails will be moving about, but when daytime rolls around, they'll seek out close, convenient shelter in the form of your trap boards. Then, you can simply walk out to your garden and pluck them off in the daytime. You can leave these boards out for a few nights in a row and see a big decline in their numbers.

Snails and slugs are drawn to orange, they will feast on the peels instead of your plants

Toss orange peels in the garden

Another strategy is to simply through orange peels out around the garden. Snails and slugs seem to really love eating these, and will often focus on snacking on them all night long instead of your plants. Sometimes they even hide the day away inside the peels so you can combine this method with the trap board method and pluck off the snails in the daytime. Every few days, compost the orange peels you placed and replace them with new peels. After a while, you'll notice fewer and fewer snails and slugs around.

Level 2 Options (Only do these if none of the previous options worked)

Set out a beer trap

Another great organic option for slugs is to set up beer traps. I put them in the level 2 options just because it may require purchasing some materials, and I'd always recommend the free, simple methods first. These work pretty well, just set out a few dishes with beer in the bottom. The snails and slugs will be drawn to the smell of the yeast and will fall in and die.

If you want to get a little whimsical with your beer traps, they make some fun little ceramic ones you can set out that are a little more like garden art.

A snail shaped beer trap. Inside the opening is a reservoir you fill with beer. The snails crawl in and drown.

Level 3 Options (Only do this if nothing else showed any effect)

Use Sluggo

Sluggo is sold as a pelleted organic and food safe option for snail and slug management. You simply shake it around your plants, I tend to sprinkle it around the edges of my bed versus all over the place. The snails and slugs will be drawn to it instead of your plants and will eat the pellets, feel sick, and leave. While this method is very safe to use around kids, pets, and edible foods, I put it in Level 3 because there are always unintended consequences when applying any treatment to the growing space. Birds notoriously eat the Sluggo pellets, and while it's supposed to be bird safe, I still feel iffy about giving this method my total sign off. It also costs money, $25-$40 a bottle, and you'll need to reapply it as it dissolves or gets eaten by wildlife. It is helpful to keep a bottle on hand for especially difficult to manage infestations as it works quickly and will stop slug damage in its tracks. Just be mindful about other control methods too so you don't find yourself relying on this one alone.

Things I would never use

• Any chemical snail killers are going to be way too aggressive for the typical home garden and should never be used in a school garden where the food from the plants is meant to be consumed.

• Salt or Epsom Salt on the soil. Dunking snails and slugs in salt water will dissolve them but don't ever put concentrated salt solutions on your garden unless you want to kill your soil. As many farmers know, saline in the soil is an herbicide when found in high enough concentrations. Salt also tends to stay in the soil too, so it's very difficult to undo the damage.

• Cayenne pepper, coffee grounds, smell based deterrents. These tend not to work for me, and they require constant reapplication so I never fool with them.

• Oil or soap based mixes. These always get really messy and sticky and the plants hate them. It's just not worth it to me to go down this road at all. Plus anything that sits on the leaves is very susceptible to sun damage so you'll probably end up doing more harm to your plants this way.

So there you go, lots of perfectly handy ways to identify and manage for snail and slug damage. Did these methods work for you? Let me know in the contact section!

---