The Basics of Composting

There are five general points to consider when starting your compost pile

1. Size
2. Water
3. Surface Area
4. Food
5. Air

Each of these components represents one of the vital pieces to a healthy compost pile. Here is a quick rundown of what each piece entails.

Size: A compost pile needs to be a minimum of 1 cubic yard (or cubic meter). It should not be any larger than 2 cubic yards though. a 3 foot wide by 3 foot tall by 3 foot deep space is required (with 5' x 5' x 5' being the maximum)

Water: Moisten the compost pile so that it has the consistency of a wrung out sponge. The decomposers that break down the organic material require moisture.

Surface Area: In order for the decomposers to break down the material in you pile, it is important to first help them by cutting the compostable material into 1 to 2" pieces. The microorganisms do not have the capacity to "eat" large pieces of food.

Food: Any healthy diet needs a variety of foods. In a compost pile, there is no exact ratio of carbonaceous ("brown") to nitrogenous ("green") material. However, it should be somewhere between 1 to 1 and 2 to 1. A 3:2 mix (60:40) or two-thirds to one-third is general considered ideal.

Air: The organisms breaking down the material in your compost pile are aerobic, meaning they require air. Make sure to provide a variety of textures (in the food you "feed" your pile). In addition, turn your pile once a week or so in order to aerate the pile.

Future posts will contain more information, but this is a "Cliff's Notes" version of what one needs to know. In the next few posts there will be a list of browns and greens (which will not be exhaustive) and other tidbits.

Vermicomposting Question (with two responses)

This question was posed to the master composter listserve and had two great responses:

I've been vermicomposting for about a month now and I notice that I have lots of gnats buzzing around my garden and house. I really don't want them around for obvious reasons. What am I doing wrong to produce so many gnats (or are they fruit flies?)?

I would guess you probably added too much food at once and/or didn't bury it enough in the bedding. Whenever I restart a worm bin after splitting, I'm judicious in adding food at first until the worm population has a chance to stabilize and start increasing again. Also, if you don't get enough bedding over what food you do give them, the fruit flies will find it before the worms have a chance to get at it in a big way. That's for fruit flies mostly. If what you're seeing is something else, the bedding may be too wet allowing other types of fly larvae to get a toe hold.

So, I'd suggest trying to work in a little more fairly dry bedding at least near the surface. While you're digging around, see if you can see how much food they've eaten so far and cut back if there is still lots that doesn't seem to have worm activity around it.

Here is the second response:

Fungus gnats, whether in vermicompost or houseplant soil, are usually associated with inhospitable conditions--usually overly wet, compacted soils or bedding, and/or lack of turning of bedding. They can also bew introduced in worm systems with an overabundance of rotting fruit--especially bananas that are left out on the counter. The adult gnats lay eggs inside the fruit & larvae thrive in the wet conditions of the box. Several things are sometimes helpful.

1. Make sure all fruit that is utilized is kept in sealed bags or in the fridge-not out on the counter. Limit quantities of fruit used & make sure everything is buried and that bedding has several sheets of moistened newspaper on top.
2. Use a hand vacuum to literally vacuum up the gnats.
3. Use a modified 'Berlese funnel' inside the box. Set up a jar with funnel, equipped with coffee filter that has a small hole snipped in the bottom of it. Pour a small amount of beer in the bottom of jar. Gnats are attracted to fermenting liquid, fly through the hole & drown or at least are unable to escape.
4. Hang a strip of yellow 'tangletrap' tape, or paint a strip or square of cardboard w/yellow fluorescent paint that you additionally spread with the sticky tangletrap compound (available at garden centers). Hang the strip under the top lid of the box. Fungus gnats are attracted to the color yellow & get trapped. Replace the strip when it is covered w/gnats

The Three Bin System

In a previous posting, three main types of bins, the three bin system (also referred to as a turning bin) was detailed. In this type of bin, the piles are built to the height of the fencing in two of the three piles. Turning the piles is easy in this type of system. Notice in the picture below that the two bins on the left are filled with compost and covered with black plastic to retain moisture. Move the compost from the middle pile to the open space at the right which will aerate the pile. Now move the pile from the left hand bin to the now vacated middle, empty bin. When turning the pile from one bin to the next, use a hay fork or some other device with significant space between the tines. This will allow for easy release of the material from the fork.


Here are some notes from the sign next to the three bin system at Gove, Denver Urban Gardens' demonstration site on the west side of Colorado Blvd. just north or 13th Avenue:.

• The unit is made of recycled wooden pallets wired together with t-post for support, if needed
• Additional pallets across the front of the unite and chicken wire on the inside will keep materials from spilling out
• Wood pallets are widely available for free (more information to follow)
• The system is modular, meaning you can add extra pallets as needed
  

Starting an Outdoor Pile

When building an outdoor compost pile, there are several options for the container (or structure) which will hold the pile in place. Here are a few options which are on display at Denver Urban Gardens' Gove Demonstration site on west side of Colorado Blvd. between 12th and 13th Avenues. The first picture (to the right) is a cinder block, three sided bin where the blocks alternate in their position. The openings in the blocks allow for air to reach the pile and ensure that aerobic (oxygen requiring organisms) continue to thrive, keeping anaerobic bacteria, which cause a smelly compost pile. The open front allows for easy access to turn the pile, again maximizing aeration.


Another option shown at the Denver Urban Garden (DUG) demonstration site is the single, three sided wood rail bin. Similar to the concrete bin, this is a single bin, with three sides. Both of these bins are slightly taller than 1 meter high (about 3 and a half feet). The slats on this bin allow for some air flow and encourage aerobic organisms as well. Just as with the concrete bin though, turning the pile is essential.

Lastly, for those with the space and resources, a three bin system (three wood slat as seen in the picture or three cinder block bins next to each other), offers greater flexibility. In the case of the cinder block bins, ensure that the pile has maximum aeration. If you make a three bin system, leave one of the three bins unused for future "mature" compost. The two simultaneous bins will reduce in volume by nearly 50%, which will fit nicely into the third, open bin when they have finished decomposing. For a three bin system, it is important to have enough matter to build two separate piles. For most urban backyard composters who choose to make an outdoor pile, there probably will not be enough material to adequately fill two cubic meters of volume.

Questions, Problems, Concerns?

Post questions, problems or concerns on this website (blog) and members of the community can reply for everyone to see. If your compost pile is just sitting there like a pile of refuse, write a post explaining what it is you are doing and what happened leading up to the problem. If you have a fix for other people's issues, write a comment on their post and help them activate their compost pile.

Beautiful Compost

Roberto's compost video