Worm Composting Indoors

One of the fastest growing and popular ways to compost indoors is through vermicomposting or composting with worms. This method is relatively maintenance free, easy, convenient, and stink-free. Setting up costs less than most people spend on soil for flower beds, pots, or gardening and can save money in garbage collection and other fees as well.

Most of the up front costs for indoor worm composting is the purchase of the worms themselves (you can’t use ordinary earthworms) and a pre-built worm bin (if used). A purpose-built, purchased worm bin will cost more up front, but will save a lot of maintenance time down the road, so the choice is a matter of preference and time/energy input as well as economics.

Maintaining Indoor Worm Bin

If you select to make your own worm bins (it’s easy), be prepared to spend three or four hours a month working with your bins – a few minutes each day plus a more involved harvest when you move the worms and clear their compost. You can also expect to have occasional deaths in your worm family and some escapees who get out of the bin as well.

When maintaining your bin, you’ll need to make sure the scraps are put in so that the worms can get to them. With pre-built bins, this is usually just a lid you open and throw the scraps into. In a homemade bin, you’ll need to lift litter or other cover for the worms and put the scraps in then cover them up again. In other words, with a home made bin, you’re putting the scraps almost directly onto the worms themselves whereas a pre-built bin will likely have this set up to allow the worms to crawl to the scraps instead.

The rest of the maintenance is in clearing out the ready-to-use compost so that the worms don’t get sick from their own leavings and cleaning. With a homemade bin, you’ll need to either make a second one so you can quickly transfer the worms and uncomposted materials over or a temporary home for the worms and materials so you can empty out the bin and clean it before setting it back up again. Often, you’ll have to separate the worms from the compost by hand unless you can devise a trap to do this for you.

Pre-made bins will have the worms crawling out of the compost and towards the new scraps as you periodically add new trays, rotating full and empty trays through the system. The full tray (usually on the bottom) can be removed, emptied, cleaned, and then placed on top to catch the fresh scraps as the worms finish composting those in the other tray. Many pre-built worm bins will have 2 or 3 trays so that you can harvest compost every week or two.

One problem that any worm bin, especially home made ones, will have are fruit flies. Sometimes these little pests are attracted to the bins and the refuse within and will congregate. Simple traps made from a jar and funnel or an empty soda bottle can be built to combat this. They are easy to make and work very well.

Using a half-quart jar, take a sandwich bag and cut a small hole in one corner. Use a rubber band or string to tie the bag to the open mouth of the jar so that the hole hangs down into the jar, creating a funnel shape. Fill the bottom of the jar with beer or apple cider and a couple of drops of dish soap. You can build the same thing by taking a small (12oz) soda bottle, cutting the top third off and turning it over to make the same funnel shape, then taping it in place. Use the same filler. The flies will be attracted to the liquid, but will find it very hard to get out of the container once inside.

Benefit of Buying a Worm Bin

The greatest benefit, as you can probably see, from buying pre-made worm bins is that they are more convenient and save a lot of maintenance and effort. They are usually nearly escape-proof and are easier to keep clean and orderly as well. Most people will look at a professionally made worm bin and likely not even know what it is unless you tell them.

Want to learn more about indoor worm composting?

See these websites:
Indoor Redworm Composting from Maryland Cooperative Extension
Worm Composting from Clemson Cooperative Extension