How Much Waste Can Worms Eat?

Here are a couple questions from Leslie:

hello, I started my bin about a month ago and I wanted to know two things-
how much kitchen scrap (in lbs? or kg..) can 1000 worms handle (in an approximately 2 ft x 4 ft bin) per week? Also, how soon before the worms start reproducing? I’m concerned about too little or too much intervention with the worms so any guidance is greatly appreciated. Thanks! -Leslie

Hi Leslie,
Those are really good question (some things a LOT of people are wondering about, I’m sure), but the first one is also a tough question to give a firm answer for. One of the challenges of vermicomposting is that there are SO MANY variables that can influence the success of your worm bin, and the overall health and well-being of your worms. As such, trying to come up with absolutes based on various calculations can be pretty challenging – at least for the average worm bin owner.

What you do with your waste materials (before putting them in the bin) ALONE can have a massive impact on the productivity of your bin. Obviously, if you add your wastes simply as they become available, without taking any steps to help the process along, you will end up with a bin full of undecomposed material pretty quickly.

If on the other hand you freeze your waste materials or let them age for a period of time, then blend them up before adding them, you will greatly speed up the process, thus effectively boosting the processing power of your worms.

The type of waste can also have a significant impact on the quantity of waste that can be added every x number of days. Tests using highly optimized professional flow-through reactors have shown that worms can potentially consume 4-6 times their own weight in food PER DAY! I should mention that these numbers are based on consumption of grocery store produce waste (similar to homeowner food waste, I would imagine), which is mostly water to begin with.

Is it realistic to think you will see similar abilities with your worms – not likely! My point is simply that the processing ability of worms can vary WIDELY, depending on how you maintain your particular system.

Some suggest that a good guideline is 1/2 worm weight per day. In your case, since 1000 worms on average weigh somewhere around 1 lb, an estimate of 1/2 lb of waste per day – or 3.5 lb of waste per week might not be a bad guess. I’m a little hesitant to even mention that, but hopefully you will take that recommendation with a grain of salt, based on what I’ve said above.

So what exactly DO I recommend?

Let the worms be your guide! Do everything you can to optimize the process, and carefully monitor your worms’ progress – especially early on. Start with very small amounts of waste (especially if you have set up your bin ahead of time with food), and go from there based on your worms’ ability to consume the materials. Obviously you don’t need to wait until every last morsel is gone from the bin. I would suggest creating several small food pockets (staggering the creation of these over the course of a given week should be helpful as well) and simply watching how quickly these pockets of food are consumed. Once the first pocket is basically processed, you can probably set up a new one (you would have a couple others on the go already), and so on.

Moving on to reproduction…

It is very common for worms to start reproducing VERY soon after being added to a worm bin – especially if conditions are to their liking. In fact, worms don’t even really need to reproduce in order to start depositing cocoons into the bin. Reproduction is basically a means of replenishing the sperm storage organ. Once the worms have sperm they can simply keep producing cocoons (using their own eggs) until it runs out.

Given the fact that you’ve had your bin for a month, I would think that there would be plenty of reproduction and cocoon laying in your bin by now. It might not be all that obvious – but rest assured, if the worms are healthy and vigorous you will almost certainly have cocoons and young worms in your bin.

Anyway – hope this helps, Leslie!
Thanks again for the great questions

Written by Bentley on February 27th, 2009 with 4 comments.
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