Compost Worm Bin

You probably end up throwing away a lot of food after some meals. It’s okay, most of us wish we were better about food waste but it often seems unavoidable. We live in a society of surplus where many of us have more than enough for over 3 meals a day. Food donations are great but what about those leftover scraps on your plate or the food items that spoil quickly?


Arizona Worm Farm

Apple cores, banana peels, moldy bread, coffee grounds, tea bags, eggshells, old pasta, strawberry stems, leftover rice, bad broccoli, spoiled cauliflower… all that food waste ends up in the garbage and eventually the landfill where it rots and serves no purpose other than wasting more food. It’s an unfortunate side effect of all our abundance that so much just goes wasted.

But if we look to nature, we find a simple solution that helps solve our food waste problem AND helps us grow better food, faster. Vermicomposting is the natural process of using worms to aid in the composting process. This happens all the time in nature but you can set up a similar small-scale ecosystem right in your house with a worm bin.

Worm bins are great because they don’t smell, they’re completely silent, they don’t take up a lot of space, they’re very low maintenance, and all you need to do is add your garbage food scraps from time to time. You put your food and paper waste in, add a little bit of water, and the worms do the rest.

Over time the food and paper decompose, the worms eat the decomposing material and as a result, the worms produce a powerful organic fertilizer in the form of worm castings, which is basically just a nice way of saying worm poop. It’s the easiest pet animal you could imagine and it’ll help you grow amazing fruits and vegetables in your garden.

Traditional compost is a combination of “greens” and “browns.” Greens are anything you eat: fruits, vegetables, and grains. Browns are anything that was a tree: paper, leaves, cardboard, and twigs. Greens provide nitrogen and browns provide carbon. After the composting process, you’re left with a highly active organic soil that you can use for gardening.

Vermicompost takes that to the next level by using the exact same foundation of compost: “greens and browns” but also adds the benefit of worms. When those worms are added to the composting process, they help consume the decomposing material and poop out a ton of nutrients that plants love. Those worm castings are a super fertilizer that will help your plants grow bigger, stronger and faster.

There are 3,000-4,000 varieties of worms but there are a limited number of worms that operate at the compost level. Genetically worms will live in 3 different layers of soil. You have worms at the top composting level, at the deeper root level, and the deep burrowing worms like earthworms. The most common composting worms that most people are familiar with are Red Wigglers, European Nightcrawlers, and African Nightcrawlers.

Red Wigglers tend to be the composting worms of choice because they survive well between 30-90 degrees Fahrenheit. African nightcrawlers do well in the summer but easily die in the winter and European nightcrawlers do great in the winter but get too hot in the summer. Red wigglers find that nice balance that works well in a lot of regions. Some like to say Red Wigglers are the “Cadillac” of worms.

Given the right conditions, worms will stay in your worm bin indefinitely. They won’t escape or wander off and you never have to add worms. Worms in a worm bin will continue to repopulate themselves and they won’t overpopulate. Once they fill up their space, they’ll sit at a population threshold until they’re given more room to expand.

Worm castings are nature’s super fertilizer. They’ll give your fruit and vegetable plants a healthy dose of nutrients that foster growth. As opposed to chemical fertilizers that sink into the ground pass plant roots, worm castings stay at that root level. They’re completely organic and you only need about a 5% mix of worm castings in your compost and soil.

Worm castings also send signals to your plants that bugs are present. The plants respond by growing bigger and stronger with their natural insect defenses. This natural response will help repel all those nasty critters you don’t want munching on your leafy greens. While it won’t fight off a full-blown infestation, it will help keep your plants safe and healthy from minor bug attacks.

If you’ve seen worm castings sold in stores, you might be tempted to purchase a bag. Things like “Worm Gold” look cool with their deep black color but that color actually means those castings have gone anaerobic. Active compost and castings are aerobic and should be purchased locally or even better yet, made yourself in a worm bin.

While we want our waste recycled, we know many cities are inadequate at meeting the demand required by modern living. Just because items go in the blue bin, doesn’t necessarily mean they won’t end up in a landfill. All too often junk mail, cardboard, and food scraps don’t get properly recycled back into the supply chain. There’s no good way of knowing what happens to that waste after it leaves your plate or doorstep.

If you want to ensure that the byproducts of your day-to-day living are being recycled appropriately, take on the responsibility yourself to do something about it. Amazon boxes, paper bills, leftover dinner, and half-eaten snacks can be easily recycled in a worm bin. Instead of rotting in the landfill producing large amounts of methane, vermicomposting produces zero greenhouse emissions. It’s a practical and sustainable solution to a common problem that we all face.

With a worm bin, food waste can be handled by individuals right at home. You can take what would normally end up in the trash and feed it to your worms instead. They’ll eat up all that decomposing garbage and in return, you’ll get an active compost full of nutrient-rich worm castings. Put that compost in your garden, on your trees, and on your plants and the cycle begins all over again. It takes you one step closer to zero waste and gets you thinking about what you’re buying, consuming, and throwing away. If nothing else, it’s good to be mindful of those things as much as possible.

Everything out here is based on rotting garbage. Everything is decomposing, but if you do it right in your home bin, your bin won’t smell.

How to Build a Worm Bin

Building a bin is incredibly simple.

Get a large plastic bucket, box or bin. These are affordably purchased at any home improvement store.

Cover the bottom with damp shredded cardboard. This acts as a bedding for the worms and creates a nice habitat for them.

Add a 1″ layer of compost. This can be storebought or homemade. Use whatever is easiest for you to get your hands on.

Optional: Add some manure if you want to increase the active bacteria and nutrients in your mix.

Add a 1″ layer of damp mulch. This can be dry leaves, shredded cardboard, shredded newspaper, wood chips, or any other easily accessible “brown.”

Add the worms! Buy some Red Wigglers or other composting worm and add them to the bin. They’ll find their way to the bottom of the bin on their own.

Before you add any food, let the bin sit for a week or two as the worms adjust to their new habitat. It’s good to shine a bright light on the bin for the first 24-48 hours so the worms know to stay under the soil. They’re photosensitive and they’ll hide from the bright light just like they hide from the sun.

After a week or two, go ahead and add your first layer of “greens.” Cover a third of the bin with 1″ of your extra food scraps: apple cores, banana peels, coffee grounds, tea bags, etc

Cover that layer with another 1″ layer of “browns.” Shredded junk mail, shredded cardboard, dried leaves, all work great.

You want to make sure the bin stays moist so add water as needed. The mix shouldn’t be soupy or dripping but it should feel damp to the touch. Expect to be adding 2-3 cups of water per week depending on your climate.

Each week you can cover another third of the bin with more greens and browns.

After 6-8 weeks you’ll be ready to harvest your first batch of worm castings. At this point, it’ll just look like dirt and you can remove a third of the bin and add it to your garden. Don’t worry if you get some worms during harvest, they can survive in most gardens and the worms in the bin will repopulate themselves.

That’s it. Continue feeding your worms weekly and harvesting their castings for your garden. Vegetables, fruits, flowers, bushes, and trees – all plants love the benefits of worm castings!

Worms in a worm bin can be managed as actively or as passively as you want… At the heart of it they’re bugs, and bugs are hard to kill.

Here are a few things to keep in mind for your worm bin at home.

• Citrus and tomatoes can be very acidic and if you add too many, it can throw off the pH of your bin. Only add these scraps in moderation and this is a good reason to only “feed” your bin in thirds. If an area becomes too acidic, the worms can retreat to a safer part of the bin until those orange peels and tomato bits decompose to a more tolerable level.

• Avoid meats and dairy. While worms can eat beef, poultry, cheese, and fish, these food items take a long time to decompose and they will likely smell up your bin, attracting other creatures like rats. You want to make sure none of those foods end up in your worm bin or you’ll be dealing with more problems than you want.

• Onions are fine in a worm bin but they smell like onions so if you don’t like the smell of onions, keep them out of the bin. Coffee grounds, tea bags, and other fragrant items are a good way to keep your bin smelling fresh.

• Too dry: for the first few weeks of having my bin I was using a spray bottle to add moisture for the worms. I would spray daily and thought this was enough to keep the bin hydrated. I quickly realized my mistake when the soil became dusty and dry and I wasn’t seeing any worm activity. A spray bottle is great for frequent touch-ups but that light mist doesn’t actually get the bin saturated with water.

• Too wet: After my mistake of letting the worms dry out, I proceeded to pour cups of water into the bin at any sign of dryness. This turned out to be a mistake as well. The topsoil of the bin looked good but when I dug down into the mess it was worm soup! The worms were practically drowning in all that water and the smell was awful. The bin doesn’t drain so the only way for the water to escape is through evaporation and while I live in a dry climate, I was adding far too much water.

• Airflow. Worms breathe and need oxygen just like people so don’t clamp a lid on your bin or suffocate your worms with packed layers of food and paper. Keep things in your bin loose and breathable so you have good airflow from top to bottom. If your bin starts to smell, it’s probably because it’s not getting enough air.

• It’s all about balance. Don’t stress the worm bin. They really are low-maintenance and anything you do to “help” the worms is probably too much. They’re bugs after all, and bugs are hard to kill so don’t freak out if you make a mistake or things don’t work out right away. Set it and forget it but check on them weekly to see if it’s a good time to add more food or water.