Build Your Own INDOOR Worm Bin

If you read my post about the awesomeness of Red Wiggler Composting Worms and decided you want to give indoor vermicomposting a try, here is your starter guide. The worm bin I will describe making in this article is specifically intended to be kept indoors, year round. If you want to have an outdoor bin, there are other considerations that would alter how I would design the bin. I definitely recommend perusing the Uncle Jim’s Worm Farm blog for additional good info about worm composting.

So, without further ado, how to build a snazzy indoor worm bin!

A Power Drill with drill bit
2 medium or large sized, identical plastic tote bins with lids (mine are 55 quart sized & clear)
Proper bedding materials

1. To get started, you will prep the bedding material.
Proper bedding material is inert, sterile “brown matter” such as shredded office paper (avoid shiny advertisements or colored ink), shredded cardboard or egg cartons, or shredded leaves.

If using leaves, you can sterilize them by packing them into a stock pot, adding a bit of water, and baking them in your oven at 200 degrees (F) about an hour. Let the leaves cool before handling.

How much bedding do you need? At least enough that it totally fills the bin when the bedding is dry. After you dampen it, it should still fill at least half your bin – preferably a bit more.

Put all of your bedding into one of your two bins and add enough water to soak the material. The experts recommend making sure this water is not chlorinated so as not to harm the worms. If you have chlorinated tap water, just let it sit out for a day and you’ll be fine. Let your bedding soak in the water for a bit while you work on the next step.

2. Grab your second bin, its lid, and your power drill.
You are going to drill drainage holes in the bottom, and ventilation holes in the sides and lid. The holes should be about the size of regular pencil’s circumference. How many should you drill? Eh, more than 5 and less than 20 per each of the sides, the bottom, and lid.

If you have kids, they can have a lot of fun with this part – younger kids just enjoy getting to use the power drill and older kids may enjoy making artistic designs with the holes. You may worry that the worms will crawl out of all these holes, but don’t. The worms will only try to escape if their living conditions are unsatisfactory, and this bin will be resting inside your second bin which will catch more runaways. I’ll discuss that more below.

3. Now, drain out the water from the bin with bedding.
The water may have little bits of paper or leaves in it, so I recommend draining it into a colander outside into your garden rather than down your sink. You want your bedding to have the moisture consistency of a well rung out sponge, so ring it out if you need to.

4. Now you can put it all together!
Place the damp bedding into the ventilated bin; place the ventilated bin into the solid bin. The ventilated lid goes on top. Ta-DA! The solid bin will catch any liquid runoff and does a great job of catching worms when they do occasionally stray. The ventilated lid on top helps a healthy airflow inside all that plastic.

Remember – this is for INDOOR use only; if you used this system outside, your worms would drown in a rain or overheat in the summer (it’s not enough ventilation to handle extreme heat since the whole thing is sitting inside a solid plastic tub).

The spare lid is handy to keep under or next to the whole unit – whenever you need to pull the ventilated bin out of the solid bin to drain the worm pee (not the proper term, but that’s what I call it), you can set it on the spare lid so your floor doesn’t get wet/dirty.

5. Add your worms
You can finally put your worms in their new home. Be sure to include any material they arrived with – most companies ship worms in a sterile medium that is good bedding. If I’m giving you worms, I just scoops them up in some of their castings so you’ll also get little baby worm eggs too :)

You can just lay your worms on top of the bedding and put the lid on; they will find their own way into the bedding. Don’t bury them, as this can cause them to suffocate if they are buried too heavily. If they were shipped to you, they will be a bit traumatized. Leave them alone in a dark, quiet corner for a couple days before trying to feed them.

 Pro Tips:
  • I like using CLEAR plastic totes because worms do not like bright lights; this helps keep the worms inside their bins and off my floor
  • Always bury food for your worms or else you get swarms of gnats
  • Cut your food into small pieces or puree it; your worms will consume it faster that way
  • In ideal conditions, your worms will consume their weight in a day – so, one pound of worms can consume one pound of food per day. This is only in IDEAL conditions though; before feeding your worms again, make sure they have almost completely consumed their last “meal.”
  • Make sure they have plenty of bedding; bedding should take up at least half of the container they are in, but ideally you should keep the bedding level up with within an inch or two of the top of your container.
  • Don’t feed your worms highly acidic foods like tomatoes, raw onion, citrus of any kind, or foods soak in vinegar. Don’t feed them overly processed or salty foods.
  • Keep an eye on the water level in the bottom of your solid bin and drain off as needed. Uncle Jim says you shouldn’t use this water as a fertilizer because it’s full of bad bacteria. Eh… I disagree. Give it the sniff test. If it smells bad, dump it in the compost pile. If it doesn’t smell, dilute it with some water, shake it up to oxygenate it, and fertilize away

Well, that's all the advice I have. If you are having problems with your indoor worms, send me a message and I'll help you trouble shoot :)