The outdoor cannabis plant must endure a threat from many enemies during its lifecycle, causing great frustration for the weed grower. However, there is one pest whose visitation can promote a real sense of disgust and lust for vengeance when the grower discovers a slimy trail extending across their plants’ leaves and buds. If you grow outside then you will recognize this as the calling card of the garden gastropod – or, to give them their common names, slugs and snails.
They are particularly active after fresh rain (or watering), which makes the ground more gastropod friendly, which is why Autumn can bring them out in force. Extremely unpleasant these slimy critters will take their time (they are, after all not known for their speed). They have very tiny mouths so won’t do huge damage in one session, but they will return and as they will destroy foliage faster than it grows, they are a threat that needs dealing with!
Slug and Snail Control for Cannabis Plants
For such a slow moving assassin, slugs and snails are surprisingly effective in their hit and run attacks and with a life expectancy of 1 – 5 years they will damage this crop and hang around to damage a few more.
They move in after dark and are gone by the morning, shrinking their size and hiding away beneath tree bark, logs, rocks plant pots and planters to conserve their moisture from any exposure to the sun. Unfortunately they also have few natural predators, as animals and birds find their slime as disgusting as homo-sapiens (snakes, frogs, toads and hedgehogs are notable exceptions).
Therefore, to catch a slug and a snail on cannabis plants we must think like a gastropod, predict their movements and arrange an ambush…. *At this point we will say that what you do with them is up to your own moral compass. Some people like to destroy them, others like to relocate them. If they are being relocated however, make sure t take them far away (research shows that moving a snail 20 metres away will stop them returning).
Make The Journey Uncomfortable
In order to get to marijuana plants slugs and snails will have to cover some open ground, so militarize that zone with some unpleasant obstacles. Slug pellets are of course an option but we would prefer to promote organic measures which can be just as effective. Creating a barrier to disrupt their journey with wood ash, crushed egg shells, salt and even human hair is recommended (although be aware that you need to reset the obstacles after a heavy rain). Another great material if you live near the coast is seaweed, sun dried until crispy (sharp and salty), which can be sprinkled around the plant.
Set Up a False Home
In the same way that the Feds carry out sting operations when they set up a fake company to bring the criminals to them, we can do the same with slugs and snails. Strategically placing old carpet or some cardboard near the plants (give it a good soaking with water to make it even more appealing), provides a safe haven for slugs and snails during the day… or so they think! Remove them, at source, every couple of days.
Set a Slug Trap
A beer trap is an anti-slug and snail device which has been a traditional remedy over the ages. Old pots and cans can be filled with beer and flour (but milk and a sugary solution seems to work just fine too). Set the trap and they will come and in numbers! Traps will need regular emptying as they fill up and turn into a gooey mass very quickly. A more pre-emptive method is to bring in some nematodes which can be added to water and will live for up to six weeks in the ground. They are ingested by slugs and reproduce inside them leading to their death.
Night Patrol
By far the best way to deal with problem is to catch them in the act! After dark is the time when slugs and snails come out to feast on marijuana and going out on night patrol with a torch (especially after fresh rain) will inspire sock, awe and satisfaction in equal measures as they can be literally picked off the plant like the most disgusting low hanging fruit you can imagine…
For more tips on cannabis pest problems, check out our blog articles on biological pest control solutions for cannabis plants and Outdoor Cannabis - Stop Pests and Strengthen Plants Naturally .