Why So Many People Give Up On Worm Bins

Over 100,00 people bought the popular book Worms Eat My Garbage, and thousands of people have purchased shiny new worm bins and their first pound of red worms. All these folks begin with high expectations of turning their kitchen scraps into high-quality plant food. Unfortunately, the results I’ve seen among friends and coworkers has not met these high expectations.

That’s unfortunate, because a properly managed worm bin doesn’t just create great compost — it’s actually quite fun to go visit your little herd of worms every day. In fact, red worms are the closest thing to livestock that many city-dwellers will ever own.

Done right, a worm bin is a blessing. Done wrong, as it often is, a worm bin is a curse.

Perhaps too many people forgot to actually read Mary Appelhof’s book, or they forgot to look at the instructions that came with their bin. Somehow, (perhaps almost inevitably), things begin to go wrong.

People usually give one of the following reasons for giving up on their worm bins:

1. The worms didn’t eat the garbage fast enough, or;
2. The bin stinks, or;
3. There were flies breeding in the worm bin.

Instead of worm compost, these folks were making a small pile of garbage, often in their kitchens. Quite naturally, garbage stinks, and it draws flies.

And there’s a perfectly good reason why the worms can’t eat the food scraps fast enough — they don’t have any teeth.

One reason that the common red worm, Eisenia foetida, is also known as a manure worm is that they need the bacteria, fungi, and other microscopic beasties that make up the largest percentage of any manure pile. These invisible critters transform dead plant and animal matter into a mushy or liquid state that can then be sucked into one end of the worm. Specialized bacteria also live inside the worm’s gut and digest the material more completely.

As you can see, the worms are the animals in the bin you can actually see, but they’re the least important animals in the bin. A good, productive worm bin is home to billions of bacteria, algae, protozoa and fungi that do almost all of the work.

Then, if all goes as planned, the material is finally pushed out the back end of the worm. That “end” product is worm poop, and it’s the product that everyone who owns a worm bin hopes to harvest in large quantities.

Unfortunately, a lot of worm bins get tossed out long before that can happen. Let’s look at a few of the reasons why.

First, many people don’t put any soil at all in their worm bins. Worms have no teeth, as I mentioned previously, but they do have a gizzard. Their gizzard works just like the one in a chicken – it’s a strong muscle that uses tiny pieces of ingested soil or rocks to grind up the food before it’s passed on to the gut. Without soil, the worm’s gizzard can’t work properly.

The lack of soil also reduces the variety and numbers of bacteria in the bin, which may be even more problematical for the worms. It’s this bustling, ever-active population of micro-fauna that worms rely on.

Most bacteria in soil are aerobic, meaning that they require air, just like we do. Worms like aerobic bacteria. Most of the bacteria that survives in a soggy garbage pile ends up being anaerobic, the kind that doesn’t need air. This causes fermentation, and fermentation stinks.

The only way I know of to keep a worm bin working the way it should is to recreate a healthy cold compost pile inside the walls of the container. This means that the carbon/nitrogen level must be right. This allows the food scraps to slowly decompose without heating up, which would kill the worms; and without fermenting, which will draw flies and upset the neighbors.

Many people use shredded paper at the bottom of their worm bin, but I never do. The paper absorbs as much moisture as it can, and then eventually gets pressed into an airless, soggy mess. A better choice is sawdust, because it absorbs moisture without packing down so much, and unless you create a little swimming pool inside the bin there will be air spaces between the damp bits of wood. The worms can easily move around in the sawdust, and they love the microbes and fungi that come attached to the sawdust. Obviously, you wouldn’t use sawdust that came from pressure-treated lumber.

Worms also like bedding made from 1/2 peat moss or coconut coir, and 1/2 bagged steer manure. This material is often easier to find in the city than fresh sawdust.

Next, I would add at least a handful of good garden soil, then begin adding a small amount of food scraps. If at all possible, allow the food scraps to compost down a bit before you place them in the bin – remember, worms have no teeth, so they can’t even begin to munch on your old lettuce leaves until the microbes have turned them mushy. If pre-composting the material isn’t possible, that’s OK – just remember that it will take bit longer before the worms can go to work.

When you add a thin layer of scraps be sure to always cover it with a layer of sawdust or chopped straw. This layer of carbon-rich material will prevent flies from finding the compost, and it will help keep the bin from stinking. The carbon also helps prevent the composting material from getting too hot. If the bin seems to be warming up too much anyway, you can slow down the composting process and cool it down by mixing in some good garden soil.

Red worms love a good compost pile. Creating a good compost inside a very small worm bin is not easy, but it can be done with patience and common sense. And if all else fails, you can always do your worms a favor and liberate them into a proper compost pile at the bottom of your garden.

For a more scholarly overview of this issue, see The Role of Microbes in Vermiculture (scroll down to find that section).