How to Deal With Slugs and Snails On Cannabis Plants?

Slugs and snails may not pose any threat to you. In fact, most of us may go for months without ever thinking about these slow creatures and what their day looks like. But if you're growing cannabis, it's time you start thinking about them. 

If you're growing cannabis outdoors, slugs and snails can become your worst nightmare. These seemingly harmless creatures love munching on your cannabis leaves, causing damage that can stunt growth or even destroy your plants. 

In this article, learn about the differences between slugs and snails, when they're most active, and how to spot and control them before they wreak havoc on your crop. Whether you're dealing with a few of them or a full-blown infestation, here's everything you need to know about dealing with them. 

About Slugs and Snails

Slugs and snails may seem harmless at first glance, but if you're growing cannabis outdoors, these slimy critters can become your worst nightmare. But before we dive in, let's answer a question many of us would have — are they the same?

Are Slugs and Snails the Same? 

Slugs and snails are indeed closely related, but they have key differences that make them stand out. Snails are known for their coiled shells, which are made of calcium carbonate, providing them with a sturdy defense mechanism against predators. 

Slugs, on the other hand, don't have a shell at all, which makes them more vulnerable but also more flexible and compact. This lack of a shell allows slugs to slip into tighter spaces and maneuver through different environments more easily. While snails can grow up to 25 cm, slugs are typically smaller, reaching only around 15 cm. 

Despite their slower pace, snails often outpace slugs, crawling at a whopping millimeter per second. Both critters, however, share a common diet — vegetation, including plants like cannabis, which they can quickly damage with their nibbling habits.

When are they Most Active? 

Slugs and snails are like night owls — they prefer to snack during the dark hours of the day. You might spot a few during the day, but nighttime is when the real party starts. They typically hibernate through fall and winter, only waking up after the first spring rains — just in time for outdoor cannabis planting. 

What Do They Eat?

These little critters are strict herbivores, so you don't have to worry about them being dangerous. They can even munch on the soil if food is scarce. But when they get near your cannabis plants, they can start feasting.

Cannabis leaves are packed with nutrients like calcium, which snails need to maintain their shells. Once they find your plants, they'll stuff their faces until they're full, leaving behind a mess of holes and possibly damaging your plant's ability to be healthy.

How Do Slugs and Snails Affect Cannabis?

Slugs and snails are notoriously unpredictable pests. While they may only nibble on your plants occasionally, they have the potential to wreak havoc, sometimes destroying entire crops if the infestation is large enough. 

The extent of the damage they cause depends on a variety of factors, including the size of your plants and the number of pests present. In some cases, a few slugs or snails might go unnoticed until the damage becomes overwhelming, while in others, a small group can quickly become a major issue.

They can cause serious damage to cannabis plants in the vegetative stage and early flowering stage when they are vulnerable and tender. In other words, the plants are not completely mature and pests take advantage of that. So, if you don't pay attention to this promptly, their feeding habits can result in slow growth and stress on the plant as well as reduced overall yields. Thus, it's important to learn to recognize their damage early on so that you can keep your plants healthy. 

Apart from that, although they do not spread diseases like other insects, slugs and snails can still hurt your cannabis plants. Because of the way they feed, move, and live they accidentally spread diseases to other plants. Here's a broader look at how they may spread disease and harm your cannabis plants:

1. Contaminating Plant Wounds

The leaves, stems and branches get nasty open wounds when these pests scrape and chew on them. These jagged, torn edges can facilitate the entry of harmful fungi, bacteria, and viruses into the host plant.

As slugs and snails move, they leave behind mucus trails that may be filled with harmful microorganisms. These slime trails could settle on plant wounds and infect the plant. The slime can even settle on adjacent uninjured tissues, which makes infection more likely.

Open wounds can allow bacterial soft rot or stem rot to enter the plant. This can cause localized or systemic infection.

2. Spreading Fungal Spores

Slugs and snails can spread fungal diseases as they crawl over plants and the soil. For example, powdery mildew is a fungus that loves damp conditions, just like slugs and snails. Slugs and snails can easily carry these spores from one part of the plant to another and even from one plant to another. Before you know it, the infection has spread far and wide. 

Another fungal disease that can wreak havoc is bud rot or botrytis. If there are slugs and snails present on thick buds, they can easily carry the spores from infected buds and deposit them on other buds.

3. Introducing Soil Pathogens

Slugs and snails may spread pathogens when they interact with the environment. They may also walk on decaying matter or excrement and spread diseases to healthy plants. That said, healthy plants aren't much at risk, but if they have wounds, it can become a big problem. 

They lay their egg clusters in the moist soil that surrounds cannabis plants. When the larvae hatch and start to move, it will disturb the soil. Slugs can indirectly cause the spread of root diseases. 

Also, damp conditions will attract slugs and snails and make fungal growth more likely. This will increase the risk of root and stem disease.

4. Can Carry Harmful Organisms

While being less common, slugs and snails can also be carriers of other organisms that threaten cannabis. 

Some slugs and snails carry parasites that may harm soil or good microorganisms which indirectly may damage the plant. For example, they can introduce harmful nematodes that can cause problems with your plant roots and affect their health. 

How to Spot Snails and Slugs on Cannabis Plants?

Catching slugs and snails early is key to protecting your cannabis plants. Here's how to tell if these slimy creatures are lurking in your garden.

• Preventive Night Patrol

Slugs and snails come out at night to munch on cannabis plants. Their little slimy bodies are prone to drying so they hide in sunny or dry conditions, meaning we confirm their presence at night.

They flourish in cool, moist conditions and their peak feeding time is at night or on cloudy, humid days. Seedlings are particularly vulnerable, so consider doing these nighttime checks even if you haven't spotted any damage yet. By the time the signs are obvious, it might already be too late to save your delicate young plants.

However, you should also check your plants early in the morning when it's dewy or after it has rained for the best times. When it is dark or damp outside, use a flashlight to look for them on leaves, stems, or soil surfaces.

• Leaves full of irregular holes  

Many pests, including spider mites, can make holes in cannabis plants; however, slugs and snails make it very obvious with their irregular large holes. One of the first signs of a slug or snail infestation is the appearance of large, irregular holes in the leaves. You may notice a few small holes here and there, but if you ignore them for long, those holes can quickly turn into major damage that stunts growth or even kills your cannabis plant.

For young cannabis plants, the stakes are even higher. Even a single snail or slug can cause significant harm. These creatures are greedy feeders and can easily chew through delicate, fragile leaves, severely impacting the plant's ability to grow. In extreme cases, a single critter can devastate an entire young plant, leaving little behind but a withered stem. 

Even caterpillars tend to make holes, but they are more symmetrical, unlike snails and slugs. 

In addition, caterpillars mainly feed on the edges of the leaves but slugs and snails are more interested in the tender tissues present in the middle of the leaves. As a result, you'll see patches of skeletonized leaves when they actively feed on your favorite plants. 

Be on the lookout for these distinctive holes after wet weather or humid conditions as that's when slugs and snails are out most active.

• Shiny Mucous Trails

Slugs and snails leave behind slimy trails. These are gross yet definitive signs of these pests as they amble around at a glacial pace from one place to another. For us, these trails look weird, but they are used to deter predators and also help with mobility. 

You can look for the trails where you see silvery lines on leaves, stems, or on the topsoil. Think of these trails as maps of their movements. So, when the pests are active at night, the evidence of their presence is seen in the morning. And, guess, how you find them? Yep, just follow the trails and you'll find where they are hiding in the day! 

Remember, the risk of becoming a meal for hungry birds discourages slugs and snails from climbing high and they generally feed close to the soil line where it's safe and moist. These pests can munch on the softer parts of cannabis plants which weaken the overall plant strength. Eventually, this also attracts potential diseases. This is why you should inspect the lower leaves of your plants for holes or damaged parts. 

• Seedling Destruction

Seedlings and young cannabis plants can be devastated by slugs and snails. These delicate plants are very appealing to these creatures, which can ruin them. In fact, they often chew through the stems of seedlings and cut them off completely at the base, killing them.

A seedling's leaves may be devoured overnight, which would either stunt the plant's growth or not let it recover at all. If your newly planted seedlings disappear overnight or you see freshly severed plants, it's probably because of slugs or snails and you need to act quickly to save the other plants. 

• You Happen to Spot One

Sometimes, it's as simple as finding slugs or snails hanging out on your plants, in the soil, or hiding around your garden. Check under leaves, near the base of stems, or in damp, shaded areas where they like to chill.

Overall, slugs and snails are not only unpredictable in their feeding habits, but they also pose a significant risk to your cannabis plants. Whether dealing with young plants that can be destroyed in a day or large established plants that could be stripped of their foliage, you should never underestimate them. 

• Clusters of Eggs

Slugs and snails produce small clusters of eggs and deposit eggs in damp, protected microhabitats. These eggs are a good sign of an active infestation. The eggs are small, round, and either transparent or white like a pearl.

You can find them beneath leaves, at the base of the plants, or just below the soil surface where it's shaded and moist. Each cluster can give birth to dozens of baby slugs/seashells and they will start munching on your cannabis plant immediately. Eliminating these eggs will disrupt the reproductive pattern and minimize infestation in the long run.

• Decaying Organic Matter

You may think slugs and snails only munch on living plants, but they also love to munch on dead organic matter for food and shelter. If they go unchecked, they only make the infestation worse as rotting leaves, stems and organic mulch around your cannabis plants are common attractants or breeding grounds.

The damp and shaded areas that slugs and snails love to hide during the day will be perfect. Make sure you regularly remove dead plant materials, compost, or mulch that may be building up beside your plants to prevent them from gaining access.

How to Get Rid of Slugs and Snails on Cannabis Plants?

So, you've spotted slimy trails and holey cannabis leaves? Don't panic — slugs and snails are much easier to handle than other garden pests like aphids or mites. From manual removal to creative traps, there are plenty of ways to stop these slimy pests in their tracks. 

Here's how you can do that.

1. Remove Them by Hand

The simplest — and most eco-friendly — solution is to pick these little buggers off your plants yourself. This hands-on approach won't harm the critters as long as you handle them gently.

To make your life easier, try placing logs or curved roof tiles near your plants. Slugs and snails love hiding in these shady spots during the day. Check these areas periodically, and you'll likely find a few squatters to evict.

There's a catch though. This method isn't a permanent fix. New slugs and snails will likely find their way back, and chances are, the ones you remove have already laid eggs in the soil. Those eggs will hatch in a few weeks, meaning your garden could soon be back to square one.

If you have the time and patience to regularly patrol your plants, this method can work. But if you're dealing with a larger infestation or want something less time-consuming, consider the options below.

2. Set Traps

Don't feel like playing hide-and-seek with slugs? Let them come to you instead. Traps can make the job easier, and some options allow you to deal with them humanely.

You can set some live traps. These traps capture slugs and snails alive, letting you relocate them far away from your cannabis plants. This method avoids the use of chemicals or pesticides and keeps your garden eco-friendly.

3. Nematodes

If you're dealing with a significant slug or snail infestation, nematodes can be a game-changing pest control method. These microscopic roundworms are nature's pest controllers, thriving in soil, water, and almost every corner of the environment. One species, phasmarhabditis hermaphrodita, is particularly effective against slugs and snails.

These parasitic nematodes infiltrate their host through the respiratory tract, releasing bacteria that kill the pest within 7–10 days. It's a natural, organic solution that eliminates the need for chemical pesticides, making it safe for your cannabis plants, your health, and the environment.

Simply introduce nematodes into your garden following the instructions on the product packaging. They'll establish themselves in the soil and get to work, providing long-term protection for your plants.

4. Attract Natural Predators

Sometimes, the best pest control is letting nature do its thing. Inviting natural predators like birds, badgers, toads, and hedgehogs to visit your garden creates a balanced ecosystem and helps control slug and snail populations. 

Here are some natural predators you can bring to your cannabis garden:

• Birds

Birds love snails and slugs, but they'll only visit if your garden feels inviting. Install birdhouses or nesting boxes to attract certain species, especially during the breeding season. Installing a water source like a birdbath can also help.

• Badgers

While you may not want badgers as permanent guests, they're great nocturnal visitors for pest control. Leave small gaps in your garden fences to make it easier for badgers to pass through, especially if your garden borders open green spaces.

• Toads

Toads thrive in damp, shaded environments. To attract them, create a mini wetland by installing a small pond and ensuring there are dark, moist crevices nearby for them to shelter in.

• Hedgehogs

Hedgehog populations are declining, so creating a hedgehog-friendly space benefits both your garden and these adorable creatures. Leave gaps in your fences for easy access, and consider building hedgehog houses for shelter. In return, they'll happily snack on slugs and snails while adding charm to your garden.

How to Prevent Slugs and Snails on Your Cannabis Plant?

You don't need to wait until your plants show damage — you need to take proactive steps to keep slugs and snails away. As they say, prevention is better than cure. So, once you've dealt with the slugs and snails in your garden, your job isn't over. It's only the beginning. First, you have to make sure your garden is healthy for your plants and come up with ways to prevent this from happening again. Here are some steps you can take:

1. Remove Damaged Plant Material

Once slugs and snails have made their mark on your cannabis plants, it's crucial to start by removing any dead or damaged leaves and stems. 

First, by cutting away the parts of the plant that have been compromised, you're reducing the risk of fungal infections, which pests can often carry. These infections can spread and cause even further damage to your plant.

Second, you should trim away damaged material, allowing your cannabis plant to focus its energy on recovery. Instead of using valuable resources to try and heal parts of the plant that are no longer viable, it can redirect its efforts toward healthy growth. 

Remember, the more quickly you remove the damaged parts, the sooner your plant can begin its healing process and return to its normal growth cycle.

2. Apply Fungicide Spray

After you've cleared away the damaged plant material, it's time to protect your cannabis plants from potential fungal diseases that could have been introduced by slugs and snails. A fungicide spray will act as a barrier to prevent harmful fungi from taking hold and further weakening the plant.

When choosing a fungicide, you should pick one that is safe for plants and people, especially if you're growing cannabis for consumption. Organic fungicides are an excellent choice because they won't leave harmful residues behind. 

Look for products with natural ingredients like neem oil, potassium bicarbonate, or sulfur, all of which are effective at preventing fungal growth without harming the environment or your plant. Regular application of these sprays, especially after a slug or snail attack, will help keep your plants protected and healthy.

3. Start Working on Preventing Them Again

Sometimes, dealing with slugs and snails is as easy as picking them off one by one. But as we mentioned earlier, they almost always come back. So, after you've obliterated their population, the next step is to prevent them from coming to your cannabis plant again. 

4. Copper Barriers

Slugs and snails experience a mild electric shock upon contact with copper, making it an excellent deterrent. So, if you're growing in the ground, create a perimeter of copper mesh or wire around the plants.

If you're growing it in containers or raised beds, apply copper sticky tape to the rims of pots or beds. Remember, while this is effective for many growers, results may vary, so it's best to combine this with other methods.

5. Electric Shock Deterrents

You can also set up electric fences around your grow area to emit a mild shock when touched by pests. Don't worry, this is non-lethal, so the shock doesn't harm the slugs but keeps them out. 

Plus, it's pretty easy to maintain. Once installed, it requires little upkeep. Additionally, it also prevents these pests from spreading diseases to your plants.

6. Soil Barriers with DE and Eggshells

Sharp surfaces are highly effective in deterring slugs and snails. These pests avoid crawling over abrasive materials, as it irritates their soft underbellies. Using natural materials like crushed eggshells and diatomaceous earth (DE) creates an effective barrier that keeps your cannabis plants safe.

Crushed eggshells are an easily accessible solution. After enjoying your morning omelet, save the shells, crush them into a coarse powder, and spread them around your plants. This simple step makes it difficult for slugs and snails to approach. 

Similarly, diatomaceous earth, a natural and abrasive substance made from the fossilized remains of algae, can be sprinkled around the soil. Both these methods are safe for plants, pets, and people, making them a great choice for eco-friendly pest control. Let's not forget, DE is also quite effective against other common cannabis pests!

7. Companion Plants

Companion planting is a clever and natural way to protect your cannabis. Certain plants, like basil, lettuce, spinach, and cabbage, are more appealing to slugs and snails, effectively diverting them from your cannabis plants. These plants serve as sacrificial companions, taking the brunt of the pest damage so your cannabis can thrive.

Moreover, companion plants act as an early warning system. If they begin to show signs of pest activity, you'll know it's time to ramp up your defenses. This approach not only protects your cannabis but also helps you stay ahead of potential infestations. Someone has to take one for the team, so it might as well be a plant that's not cannabis, right? 

8. Beer Traps

Believe it or not, beer can be a lifesaver for your cannabis garden. Slugs and snails are attracted to it, and you can use this to your advantage by setting up beer traps around your cannabis plants. 

The pests will either get drunk — can't blame them, can we? — or drown in the beer, effectively removing them from the equation. To set this up, simply place shallow dishes filled with regular beer around your plants in the evening, as slugs and snails are nocturnal feeders.

Once you've set the traps, follow the slime trails the next morning to identify where the pests are coming from. When you check the traps, you'll likely find a bunch of inebriated slugs and snails that are easy to dispose of. This method is both effective and a little amusing, giving you a creative way to deal with your pest problem.

9. Coffee Grounds

Coffee isn't just a morning pick-me-up for you — it can also serve as a natural repellent for slugs and snails. The strong smell of coffee deters these pests, while the grounds themselves create an abrasive surface that's difficult for them to crawl over.

To use coffee grounds as a deterrent, simply sprinkle them around the base of your cannabis plants or mix them into the soil. 

Not only will this keep slugs and snails at bay, but it also adds a little boost to the soil, as coffee grounds can be a great source of nitrogen. It's an easy and eco-friendly solution that works well as part of your overall pest control strategy.

10. Regular Patrols

Sometimes, the most effective way to handle pests is through old-fashioned vigilance. Become the backyard bouncer for your cannabis plants by conducting regular patrols. Early in the morning, before the sun heats up, check the shady spots around your garden where slugs and snails like to hide, such as under logs, rocks, or tiles.

If you find any, simply collect them in a bucket and relocate them far away from your garden. Regular patrols for about a week can significantly reduce the slug and snail population in your garden. 

After a week of combining these methods — soil barriers, companion plants, beer traps, coffee grounds, and regular patrols — you'll notice a significant decline in the local slug and snail population. Your cannabis plants will be free to grow and thrive without the worry of these pesky invaders, giving them the best chance to reach full maturity.

Frequently Asked Questions

1. Are slugs and snails more troublesome in cannabis grown outdoors compared to indoors?

For the most part, slugs and snails are outdoor pests. They rely on damp soils, mulches, and other garden debris for their existence. But they can sometimes go into indoor grows, especially where plants are moved from outside to inside or where infested soil is used.

2. Can slugs and snails damage cannabis plants beyond the vegetative stage?

Slugs and snails can eat flowering cannabis plants, albeit not as much as vegetative plants, but they do favor tender young leaves and stems. If conditions get moist, they may munch on sugar leaves or even damage the buds of the plants in dense foliage. It is important to deny access at all growth stages.

3. Can slugs and snails spread diseases that make cannabis sick?

Yes, slugs and snails can carry fungal spores, bacteria, and viruses that can make cannabis plants sick. The paths they create introduce diseases to the injured parts of the plants which increases the chances of getting diseases. 

4. Can salt be used to kill slugs and snails?

Salt will kill slugs and snails but is not something you should use near cannabis. Salt can harm the structure of soil and the roots of plants. Insect repellents like diatomaceous earth, copper tape, or organic repellents are safer and more effective.

5. Are chemical slug and snail killers safe for cannabis plants?

Some chemical options that are safe for cannabis plants and the environment include iron phosphate-based baits. However do not use metaldehyde-based products because they are toxic to pets, wildlife, and beneficial soil organisms. Always follow the recommendations of the manufacturer.

6. Can slugs and snails wipe out a cannabis crop?

In worse cases, slugs can destroy seedlings and cause lots of damage to older plants, stunting their growth and causing crop failures; however, it's unlikely that they can wipe out an entire bunch of plants unless you have an infestation that's simply unheard of. 

Summary: How to Deal With Slugs and Snails On Cannabis Plants?

Slugs and snails may only move slowly, but don't let their speed deceive you. With the speed at which they chow down your cannabis plants, you might as well call them leopards. These slow-moving pests can deal quick damage to your cannabis plants. 

Remember, while similar, slugs lack shells and are smaller, while snails have protective shells and are slightly larger. These pests are most active at night and can destroy plants if left unchecked. 

You can identify their presence through chewed leaves, slime trails, or by spotting them directly. Here, you need to be quick in getting them out of their garden to keep your plant healthy. 

That's not where it ends, though. You also need to use some preventative measures, like setting traps, natural predators, and barriers, which can help control their population. By taking proactive steps and creating a protective environment, you can safeguard your cannabis plants from these unwanted visitors.