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Ask the Worm Guys: Pesticides and Increasing Worm Population

Here's a question we received from one of our friends.

"I would like to know how to increase my worm population, and does it matter if the worms are fed with non-organic food scraps (such as commercial vegetables that could have been sprayed with chemicals, fertilizers, and all the chemicals that could be in that vegetable)? Right now I am trying to feed my worms as organic as possible."
- At Home Worm Farmer

Organic Foods vs. Mass Agricultural Foods

I'll answer first the question on organic food materials. If it is safe enough for you to eat, it is safe enough for worms. In fact, worms have been found in studies to break down pesticides and other pollutants. A quote from a recent study in the Journal of Environmental Protection: “Studies indicated that the earthworms bio-accumulate or biodegrade ‘organochlorine pesticide’ and ‘polycyclic aromatic hydrocarbons’ (PAHs) residues in the medium in which it lives.” (Earthworms: Charles Darwin’s ‘Unheralded Soldiers of Mankind’: Protective & Productive for Man & Environment) In other words, any pesticides that remain on the food will be further broken down by your worms.

Growing More Worms

In growing more worms, there are three conditions and one variable that are essential. The three conditions are surface space, temperature, and moisture, and the one variable is feed stock for your worms.

    • Space: First, think about how much surface square feet you have in your system. This is important, as one pound of worms feed in a one foot square area. You can use any type of container, but the most important factor is the space you have.
    • Temperature: Second, maintaining a temperature between 68 and 76 degrees Fahrenheit will maximize worm breeding. Essentially, redworms like the same basic temperatures that we do as humans.
    • Moisture: It is important that you keep the area near 70% moisture. A simple test to test moisture is to take a handful of castings and squeeze. If a few drops come out, then you have a good amount of moisture.
    • Feed Stock: The biggest variable is feed stock. To speed up worm growth, do not put any citrus, meats, dairy, or heavy oily foods into the pile. The next step is shredding foods into smaller pieces. A worms mouth has no teeth and is less than 1/10th of an inch wide. The redworm is seeking out certain bacteria, such as protozoa and microorganisms, that grow on the food, and shredding helps break down the food and provide more access to these bacteria. Softer foods such as squashes, pumpkins, mashed potatoes, tofu whey, watermelon, and cantaloupe will provide great and robust worm feed. You also should add a source of calcium. Dried and crushed eggs, even a few oyster shells, can provide the needed calcium to help promote eggs/baby worm production. To little calcium and it will stunt the growth on young worms. Lastly, make sure that your food is covered well. 

Once you have all these conditions, you will see your worms crawling heavily on the sides, on the lid, and everywhere in between. Do not be alarmed, as this is breeding behavior. The way to tell this from streaming behavior (a dangerous condition where they get in a straight line and leave the area or container at the same time) is that are they traveling in many directions in the search for breeding partners. You will also see balls of worms, and these are breeding balls that form to provide mutual egg insemination. If you maintain these conditions, in less than 90 days your worm population will have doubled.

If you need to maximize space, then you need to remove as much vermicastings as you can as this will provide more space. You can do so by dividing your tank and then doing the above step alls over again. 

Special final note: If your bins fill with worms and all you do is continue to feed it (rather than dividing your tank), they will stabilize their population and grow larger (they will have fewer babies naturally).


  • 5* I’m starting my 1st compost; I’m using a tire n lid for a bin

    This helps me immensely, get off to a great start, added to otha research I’ve done

    Danye Echtinaw
  • I just received a bag of red wiggles yesterday 16 Sep)

    Compost won’t b ready for 4 days

    How do I keep worms in the shipping bag from dying

    (I’m planning to put in a brown bag: yard dirt, a lb of “green” scraps, 1-2 toilet paper rolls, n some soaked cardboard, and top it w the burlap bag they came in—-till compost bin (dark tote w lid) is ready to add the worms
    Also: 4024529826

    Danye Echtinaw

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