How to protect your cannabis plants from slugs and snails

How to protect your cannabis plants from slugs and snails
Luke Sumpter

Slugs and snails have a massive appetite for cannabis leaves, and won't stop unless dealt with properly. Use natural predators, barriers, and traps to keep them at bay.

Growing cannabis outside has many advantages. Large amounts of space means that genetic sativa giants can be cultivated and massive yields can be achieved. Plants also have access to their natural environment and surge when exposed to the UV rays of the sun.

These advantages don’t come without a cost, though. Many creatures with an appetite for cannabis leaves inhabit gardens. Slugs and snails are among these potential pests.

Slugs and snails are classified as gastropods, soft-bodied creatures that belong to the mollusc group. They feature a muscular foot that they use to move around, which also leaves a long, slimy trail behind, an easy way to tell that they are active in your garden.

Some pests will only nibble on foliage, but slugs and snails can devour entire leaves and flowers in their quest to satisfy their appetite. The loss of a couple leaves is no big deal, but if growers let slugs and snails take a hold, they can really do some serious damage.


Signs of slugs and snails

Slugs and snails are on the larger side when it comes to garden pests, making them easier to detect. Perhaps they are relaxing on the underside of a fan leaf or slowly making their way up a stem.

However, you might have noticed some severe damage to your plants without directly seeing the culprit. But you’ll still know they were there if a slimy trail of mucous can be seen painted across fan leaves. Depending on whether these trails are fresh or dry will determine how recently they have visited your garden.

Another telltale sign of slugs and snails is irregular bite marks on your cannabis leaves. Because these creatures feature rasping mouthparts, they leave behind spider web-shaped marks. Due to their ferocious appetite, these bite marks can be found anywhere on your plant’s anatomy, all the way from the roots to the highest leaves.

Snails and slugs become particularly active during the dark and in wet weather. If you are convinced you are dealing with them but have yet to see them for yourself, head out into the garden at these times and see if they make themselves apparent.


Once you have determined that you have slugs and/or snails in your cannabis garden, it's time to do something about it.

Chemical control is an option, but it isn’t advised, and organic growers certainly won’t take this path. Synthetic chemicals can cause damage to the environment and other wildlife, potentially reducing the biodiversity of your garden.

There are numerous non-chemical control methods that have proven to be effective, and don’t pose a threat to the health of your garden.


Encourage predators

Just like slugs and snails have an appetite for your cannabis plants, other animals have a desire to eat slugs and snails! Encouraging natural predators into your garden is a good way to control their population, and it also saves you from doing the work. Toads, thrushes, hedgehogs, and ground beetles all make a meal out of these pests.

Building small shelters throughout your cannabis garden will attract toads. They will happily make these shelters their home in order to avoid sunlight during the day. Shelters are easy and cheap to make, and can be built using an upside down plant pot propped up with a few stones.

Building a small wildlife pond is another way to attract these creatures, and it’ll also add some awesome character to your grow space.

You can encourage thrushes to regularly visit your garden by putting out food such as kitchen scraps and birdseed. They are also attracted to water sources, so placing a bird bath outside is a great way to get them to visit. They value small shelters and nesting sites; putting up a small birdhouse will encourage them to come along and swipe up some slugs and snails.

You can attract hedgehogs to your garden by building them a hibernation home. This structure can be made out of a strong plastic or cardboard box. Cut a hole in the box and fill it with leaves and straw.


Another way to deter slugs and snails is to physically prevent them from entering your cannabis garden. Creating a perimeter around your plants using sharp materials such as lava rock or gravel is a great option. Slugs and snails are soft-bodied beasts, and they won’t like what they feel as they slide over this protective barrier.

Copper also works as a barrier against these pests. This mineral is the enemy of slugs and snails, reacting with their slime and disrupting their nervous system. Copper strips can be attached to the edge of plant pots to stop them from going any further.


Place traps

Hollow out half of a melon or piece of citrus fruit and place it into the ground at the level of the soil. Slugs and snails will be attracted to these scraps, and you’re more than likely to find them chilling out inside them in the morning. Empty these traps far away from your cannabis crop.

Beer traps are very effective against these pests. Whether they love a good party or simply can’t resist the smell, something about beer is very attractive to slugs and snails.

Bury a jar into the soil so the top is exposed, and fill it part of the way with beer. Make it very shallow if you don’t want them to drown, and empty them each morning.


If you like to get your hands dirty and have a hunter's instinct burning inside of you, grab a torch and head out into the garden at night when these animals are the most active.

Check your plants regularly and simply remove slugs and snails by hand when you see them getting all slimy over your prized plants.

Luke Sumpter
Luke Sumpter

Luke has worked as a cannabis journalist and health science researcher for the past seven years. Over this time, he’s developed an advanced understanding of endocannabinoid system science, cannabis phytochemistry, and cultivation techniques.