Cannabis and Vermiculture: Sustainable Fertilizer for Plants

What is vermiculture? It either sounds like something artistically sophisticated or a subculture devoted to vermin.  Put simply, it’s the use of worm poop. Gross, right? Wrong!

Worm castings, also known as worm poop or vermicompost, are an incredibly effective and sustainable source of fertilizer for all plants.  Vermiculture utilizes the decomposing powers of worms to turn organic waste matter into nutrient dense hummus.  Think about all of the produce residue that you throw away on a weekly basis: banana peels, citrus rinds, apple cores, soggy lettuce…  Rather than sending this organic material to the landfill, bring them back to the earth.  Vermiculture is a way of naturally recycling; it puts what came from the earth back into the earth so that more can come forth.

How can Vermiculture Benefit My Cannabis Plants?

The same way that it benefits all plants.  First, because it is an organic fertilizer, it will be broken down slower than synthetic fertilizers decreasing the chances of fatal nutrient overdose in your plants.

Vermicompost is also great for the soil.  It enhances soil consistency, water absorbency, and aeration.

Vermicompost can help to replace the nutrients lost after cannabis is harvested, and that is a great cost saver given the hefty price of soil

In addition to improving the overall structure of soil, vermicomposting introduces symbiotic microorganisms and fauna to the soil.  These organisms assist in the decomposition of organic matter.  They also aid in fighting harmful pathogens by turning them into nutrients thereby creating a sustainable ecosystem where plants can thrive.

These benefits play an important role in bolstering the cannabis plant’s root system.  The marijuana plants will have stronger roots that are fast growing and densely branched.  Strong roots are a natural defense from overwatering, drought, disease, and sharp spikes and/or dips in temperature.

Okay, I’m Into the Worm Poop.  What Next?

In order to properly engage in vermiculture, you will need four items: several thousand red worms, moist bedding, an aerated container, and organic waste.

Step 1: Determine the size worm bin you will need.

Weigh the amount of organic waste you discard each week for a few weeks until you are satisfied with an average. For every pound of waste you plan to bury in your worm bin, you should provide your worms with one square foot of surface.  A common size for a two-person family is an 8” x 2’ x 2’ box.  Since the worms you will be using are shallow diggers, it is best to build a bin that is shallow with a large surface area rather than one that is narrow and deep.

Step 2: Build your bin.

To build an 8” x 2’ x 2’ bin, you will need thirty-six 6d pallet nails, a drill with a 1/2” bit, a hammer, one 24” x 24” plank of 5/8” CDX plywood, and four 8” x 23, 3/8” pieces of 5/8” CDX plywood.

Use three to four nails to put the sides together, then hammer on the bottom.  Use the drill to create nine 1/2” holes in the base of the bin for drainage and aeration, and then set the completed bin on legs to allow for air circulation. It’s a good idea to place the finished product over

It’s a good idea to place the finished product over the plastic sheet.  The worms won’t crawl out, but some of the bedding may slip out of the holes

This bin should last two to three years.  Rotating between two boxes to allow each one time to dry out and sealing all surfaces with a waterproofing substance will extend the box’s longevity.

Step 3: Lay down the vermicompost bedding.  

The absolute best bedding for a worm bin is shredded corrugated cardboard, but torn newspaper, animal manure, and leaf mold work well, too.  You can add decaying leaves, leaf mold, and manure to a newspaper or cardboard bedding since those form the natural habitats for red worms.  You can add a small amount of peat moss to help with water retention and keep the newspaper from matting, but too much peat moss is acidic and can hurt the worms.

Step 4: Choose your worms.

Because of their quick reproduction in confinement, ease of accessibility, and voracious appetites, the red wigglers like Lumbricus rubellus or Eisenia foetida are the best earth worms for the job.  Gardening and fishing companies sell these worms all year long.

When it comes to quantity, a good ratio to use is a worm-to-garbage ratio of 2:1.  You will need two pounds of worms for every pound of garbage you plan to bury.

If the seller you are purchasing from does not measure their worms in pounds, you can estimate that 1000 worms is about one pound

As long as you upkeep your worm bin, you can bet on the worms sustaining themselves.  The population will adjust based on the environment and available food, so you may end up with slightly more or less worms than you originally purchased when it comes time to sort them from the compost.

Step 5: Set up your vermicomposting system.

Worms need their bodies to be damp in order to breathe, so the bedding must be between 75 and 90 percent water.  In order to get your bedding to that level, weigh the dry bedding material, place it in a garbage can, add three times the pounds of water as dry bedding, add two to three handfuls of soil, and mix. Then dump the mixed bedding into the worm bin.

Place your worms on top of the bedding.  They are photosensitive, so they will quickly burrow into the bedding to escape the light. Once the worms are out of sight, dig a hole in the center of your bin, place the organic waste you intend to bury into it, and cover it with the bedding.

The best waste to feed your worms is organic materials: left over produce and peels/rinds, lawn trimmings, and crushed egg shells are all excellent sources.  Don’t put anything nonbiodegradable (plastic, foil, glass, sponges) into your bin.

You should also keep dairy and meat out of your bin since those can create a rodent-attracting odor

Once you have buried your garbage, place a plastic sheet over the bin to keep out light and retain water.  Rotate spots where you bury garbage from that point forward.

If you are providing your worms with an adequate environment and enough food, you can basically leave them alone for the next few months.  Continue to bury garbage each week, but there is no need to check in on your wigglers every day.

Step 6: Sort the worms and your compost.

About every four months, sort your worms from the compost.  This is a time consuming but simple process.  You will need a six-foot-square sheet of thick plastic, a lamp or other light source, a plastic container to hold the worms, and a garbage can or any other heavy duty container to hold the compost.

Before you begin the sorting process, you should prepare fresh bedding so you can immediately put the worms back in their bin once the sorting Vermiculture, natural cannabis fertilizerprocess is complete.

First, dump the contents of the worm bin onto the large plastic sheet. Make nine cone-shaped piles out of the dumped material.  The light will cause the worms to move toward the center of each pile.

Once the worms are hidden in the piles (this takes five to ten minutes), remove the surface of each pile.  This will cause the exposed worms to move deeper into the mounds.  Place the worm-free contents into your compost-holding container, and repeat the process until all of the compost is gone and nothing but worms remain.

Put the worms in the plastic container.  Once the process is completed, transfer the worms back into their bin with the fresh bedding.

Step 7: Use your compost.

The vermicompost you have just gathered is full of nutrients and synthetic free, so it poses almost no danger to your plants.  You can use about three pounds of your compost for every 100 square feet of crops.   Sprinkle on a bit more every couple of months.

Step 8: Store your compost.

Make sure that you keep your stash of compost damp but not wet for optimum use.  Allowing the compost to dry a little before storing it helps to deter the formation of anaerobic bacteria which can turn this odorless substance into something noxious.  Place the compost in a non-airtight container with holes drilled into its lid.  This well-aerated container can give your compost a shelf life of around three years.

References

Applehof, Mary.  “A Step-by-Step Guide to Vermicomposting.”  Mother Earth News.  Jul./Aug. 1983.   

“Compost Tea for Marijuana Plants—Benefits of Brewing Aerated Vermicompost Tea.” Worms for Weed

“Storing Vermicompost.”  Nature’s Footprint.  2015. 

“Vermiculture Composing.”  Wormpoop.com.  2009. 

Cannabis and Vermiculture: Sustainable Fertilizer for Plants was last modified: by
Dianna Benjamin

About the author: Dianna Benjamin is a freelance writer, teacher, wife, and mom horrified and fascinated by social justice and our inability--yet constant pursuit--to get it right.