Vermicomposting (Worm Composting) - Pros and Cons

I've had tens of thousands of worms in my kitchen in years past, and I've never once tried to get rid of them. Now, after transitioning from full-time travel to a homestead, I'm acquiring several thousand more.

We don't operate an invertebrate zoo. We're using worms to help reduce our food waste and provide free compost for our garden.

Many people already know about the benefits of having a compost pile in their yard. However, vermicomposting is another option for reducing food waste and creating rich, fertile compost for your garden. This free compost can help you grow healthier plants with higher yields.

However, vermicomposting isn't quite as simple as you think. If you're not careful, your worm bin can turn into a smelly, wet mess you dread opening each day.

I've started and maintained several worm bins over the past decade, and I can tell you firsthand there's a learning curve to vermicomposting. But starting a worm bin is a fantastic learning experience, especially if you have kids. Your worms can provide you with rich, high-quality, nutritious compost that's far more beneficial than anything you can buy at the store.

What Is Vermicomposting?

Vermicomposting uses specific earthworm species to break down food waste and turn it into rich, nutrient-dense compost you can use in outdoor home gardening or container gardening. Red wigglers are most popular because they consume matter near the surface — unlike other worm species, such as night crawlers, that burrow much further down to feed.

Vermicomposting uses closed bins that create a dark, hospitable environment where worms can thrive, reproduce, and consume organic matter. When the worms digest the organic matter, they produce worm castings, which are worm excrement. These castings, along with uneaten organic matter in the bin and helpful bacteria, are the compost.

Pros of Vermicomposting

Most people don't daydream about having a bin filled with thousands of worms eating all their food scraps and leftovers. However, vermicomposting is becoming more popular as people look for ways to live a zero-waste lifestyle and minimize their impact on the environment. And when done correctly, vermicomposting can provide you and your garden several benefits.

1. It Helps Eliminate Food Waste

According to the United States Department of Agriculture, Americans waste 30% to 40% of the food supply each year, which averages 218.9 pounds of food per person. The Guardian estimates this waste costs the average family of four over $1,600 per year.

One of the most significant advantages of vermicomposting is that you get to see how much food your household wastes daily or weekly. Every time you toss leftovers you didn't eat or fruit that went bad, it's like watching money go down the drain. That can motivate you and your family to make changes to reduce food waste and save money on groceries.

When you vermicompost, you don't waste any food. You get rich compost and highly beneficial “worm tea” (a liquid fertilizer made from soaking worm castings in water).

2. It Helps Reduce Greenhouse Gasses

Vermicomposting benefits the environment by reducing greenhouse gas emissions.

When organic matter decomposes in landfills, it produces high levels of methane gas, which according to National Geographic, is a greenhouse gas 28 times more potent than carbon dioxide when it comes to warming the planet. Giving your worms your leftover food and kitchen scraps keeps all that waste out of landfills and helps reduce emissions. Although the food emits some methane as it decomposes, it's dramatically less than the methane produced in a landfill.

3. It Leads to Better Plant Growth

A 2019 study published in the Journal of Pharmacognosy and Phytochemistry found significant increases in nutrients like potassium and carbon in vermicompost compared to soil without compost. And a 2016 study published in Ecological Engineering found that vermicompost stimulates the growth of  beneficial fungi and bacteria.

All these nutrients provide an essential boost for plants, help aerate the soil, and aid with water retention. And there's plenty of scientific research to back that up.

A 2008 study published in Bioresource Technology found that vermicompost improved root formation, shoots, and leaf area in some plant species. A 2007 study, also published in Bioresource Technology, found that soil enriched with vermicompost had significantly higher tomato yields.

Additionally, a 2006 Ohio State University research article published in BioCycle says that even minimal amounts of worm tea added to tomato plants positively affected growth and crop yield.

A 2009 Griffith University study published in the American-Eurasian Journal of Agricultural & Environmental Sciences notes that because vermicompost is rich in beneficial nutrients, microorganisms, and minerals, plants are better able to resist pests and disease.

4. It Provides Compost More Quickly

Depending on your compost pile's location and temperature, it can take three to 12 months to get usable compost from a conventional outdoor pile.

With vermicomposting, most people get usable compost in three months or less. And you continue to get compost every two to three months after that.

5. You Can Compost Indoors

Even if you don't have a backyard or garden, you can still try vermicomposting. Many people living in apartments keep a worm bin in their kitchen or closet to reduce their food waste and have a steady supply of rich compost for their houseplants or container garden.

Cons of Vermicomposting

When maintained correctly, a healthy vermicompost bin smells earthy and natural. It's free of pests and noticeable insects. However, it can be challenging to keep a vermicompost bin's environment at perfect levels to avoid these problems, especially when you're still learning how to maintain that balance. So there are definitely some downsides to starting a worm bin.

1. It Can Create Odors

Worms can only eat so much food per week. If you put too much food in your worm bin, it quickly starts to smell. Poorly ventilated containers also develop foul odors and too much moisture.

If your worm bin is too wet, foul-smelling leachate (a dark anaerobic liquid that collects when too much moisture develops) can pool at the bottom. This leachate isn't the beneficial worm tea so many gardeners rave about. It smells terrible and can drown your worms. It could also contain toxins or bacteria that can make you or your worms ill.

2. Maintenance Can Be Time-Consuming

Vermicomposting doesn't require a daily commitment. However, it does take as much or more time than a conventional compost pile.

For example, your worms can process food scraps faster if you cut them into small pieces or process them in a blender. Many people don't have the time or inclination to prepare their food scraps.

3. Harvesting Is Time-Consuming

Harvesting your compost can take an hour or more. But commercial worm bins have trays to make harvesting the compost much less time-consuming.

Final Word

Vermicomposting is a fantastic way to reduce food waste and help reduce greenhouse gasses. And if you have a home garden or container garden, there's no better way to get rich, nutritious compost for your plants.

The hardest part of maintaining a healthy worm bin is keeping it balanced. And like many people, that's where I made the most mistakes early on.