How to Rid Your Cannabis Plant of Slugs & Snails

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In Common Marijuana Insects and Pests to Look Out For we mentioned that slugs and snails are one of the most common pests that plague marijuana. However, they are not the worst. Although these molluscs are voracious eaters and can destroy your plant when left alone, they are easy to prevent and get rid of.  

How to identify slugs & snails

Snails and slugs are easy to identify. The two are pretty much the same except that snails have a trademark “few-whorled” spiral shell. Meanwhile, slugs usually come in black, brown or gray. Both have two optical tentacles and two smaller sensory tentacles that allow them to find food even from a distance. These soft-bodied pests leave a glistening trail of slime wherever they go. Even though they move slowly, these gastropods are good at hiding and only come out at night. 

Snails and slugs like to hide and lay eggs in damp, dark spaces. On your plants, you may find these eggs on soft soil but some snails like to keep their eggs inside their bodies until they hatch. The eggs look like a bunch of tiny, white or pale gelatinous globes around 3 to 4 mm in diameter.  

Why are slugs & snails bad

A bunch of snails and slugs can devour your whole plant, leaves, buds and all if left unchecked. Some slugs can even go underground to attack plant roots. Since both are common garden pests that will eat almost any kind of plant, they are usually a problem for outdoor growers but not so much for the indoor grower.

Seedlings are especially vulnerable since these molluscs prefer munching on tender foliage and stems. These nocturnal pests can eat several times their weight, mostly at night to avoid predators.   

When you might notice slugs & snails

Since snails and slugs are nocturnal feeders, you probably won’t catch them in the act but they will leave holes or munch off the edges of your plant’s leaves. They can even finish smaller leaves off in one night, leaving just the end of the stem. If you see this kind of damage along with a shiny trail of slime, that’s a sure sign of a snail or slug problem.

Organic methods to deal with slugs & snails

Even if you’re growing indoors, it’s possible for snails and slugs to invade your grow area especially if you have a garden at home. Fortunately, these pests are easy enough to deal with using organic and natural methods.

  • Beneficial nematodes – Using beneficial nematodes is a great way to address pests in your plant’s soil. This biological pesticide will kill snails, slugs and other common marjuana pests like thrips and mites. Phasmarhabditis hermaphrodita is particularly effective against slugs but will also kill some snails.  

  • Barriers – Keeping these pests out can be as simple as placing an anti-snail barrier around your plants. You can put a ring of copper tape or wire, copper sulfate or salt around your pots to prevent these critters from climbing in. Copper reacts with a snail or slug’s body and shocks it while salt irritates and dehydrates these gastropods’ soft, slimy bodies.

  • Diatomaceous earth – This is a powder made of fossilized remains of aquatic microorganisms called diatoms. These diatoms will scratch the bodies of slugs and snails, eventually killing them. Diatomaceous earth can cause health problems when accidentally inhaled, so you need to wear a mask when handling it.

  • Traps – One of the most popular ways to get rid of slugs and snails would be to lay a beer trap that can attract these pests from a few feet away. You can also use commercially-made snail baits if you don’t like wasting beer. 
A fennel plant
  • Companion plants – Companion plants are always a great option for keeping slugs and snails away. They particularly dislike aromatic herbs for cooking such as fennel, rosemary, and basil.

  • Anti-snail sprays and solutions – You may also see a lot of other natural or organic pesticide sprays online like Monterey’s Sluggo Plus. However, most of the methods mentioned earlier are already fairly effective in controlling slugs and snails that most home growers rarely need to use these products.  

Non-organic methods to deal with slugs & snails

Like what we’ve mentioned in several of our other guides, marijuana home growers rarely have the need to resort to non-organic methods since a combination of natural pest control solutions are more than enough. However, you may come across some anti-snail/slug products that could contain synthetic pesticides. It is best to avoid molluscicide products that include these as an ingredient:

  • Metaldehyde
  • Methiocarb
  • Carbaryl

Frequently Asked Questions on Slugs & Snails

How fast do slugs and snails reproduce?

Snails and slugs have a lifespan of 1 to 5 years. These mollusks can lay around 80 eggs per cycle and as many as 400 per year

What are signs that you have a snail or slug infestation?

Since snails and slugs are nocturnal feeders, you probably won’t catch them in the act but they will leave holes or munch off the edges of your plant’s leaves. They can even finish smaller leaves off in one night, leaving just the end of the stem. If you see this kind of damage along with a shiny trail of slime, that’s a sure sign of a snail or slug problem.

Are slugs and snails harmful to cannabis plants?

A bunch of snails and slugs can devour your whole plant, leaves, buds and all if left unchecked. Some slugs can even go underground to attack plant roots. Since both are common garden pests that will eat almost any kind of plant, they are usually a problem for outdoor growers but not so much for the indoor grower.

Seedlings are especially vulnerable since these molluscs prefer munching on tender foliage and stems. These nocturnal pests can eat several times their weight, mostly at night to avoid predators.   

Conclusion

Snails and slugs are often only a problem for outdoor growers. Nevertheless, most organic preventive methods intended for pests like aphids, thrips and mites, like using diatomaceous earth, beneficial nematodes, companion plants, coupled with proper plant care, will be enough to keep these unwanted molluscs away. As always, it is of utmost importance that you check your plants everyday because these nocturnal pests will strike when you are not looking and you’ll only likely know that you have a problem based on the symptoms.

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