SCRAPS TO SOIL: LET’S BREAK IT DOWN

Composting is simply speeding up the natural decomposition process. Fret not, the process will happen with or without human help - it’s just a matter of time. Even if you throw everything in a pile and walk away (we’ve all been there), it will eventually break down and turn into soil - it just might take a year or two. This is called cold composting. Now if you want to create soil that is free of weed seeds and pathogens, then you need to get that pile cooking. This is a process called hot composting, which essentially involves creating the perfect environment for decomposers to thrive. Just like us, they need carbon, nitrogen, water and air. It’s equal parts art and science - and with a little trial and error, you’ll have it down in no time!

Here are the 5 most important things to get started:

Location

Choose an outdoor space for your compost. You will need at least 3 cubic feet of space and access to water. Ideally, you want to start your pile on bare earth, so worms and other beneficial decomposers can work the pile. Do not make it too close to your house, because you’re trying to lure decomposers. Choose a well-drained area of your yard, preferably one that gets some sunlight.

Materials

Every healthy compost pile needs a good balance of carbon and nitrogen sources. Experiment to find the right balance for your pile – you’ll find the right mix over time.. Remember, composting is both an art and a science!

Let’s keep it simple:

Carbon comes from the ”brown” and dry materials like straw, dried leaves, cardboard, shredded paper, untreated sawdust or corn stalks. This gives the decomposers food energy – just like eating carbs does for us. You always want to have a carbon source on hand, so you may have to stockpile leaves and cardboard.

Nitrogen comes from the “green” and wet materials like fruit and veggie scraps, grass clipping coffee grounds or manure. This helps microorganisms grow and multiply.

DO NOT add any meats, dairy, oil or pet waste to your pile! Just don’t.

Now you have your materials, so let’s layer it up – like making a lasagna!*

  1. Start with a layer of small twigs or straw, at least 6-8 inches deep. This helps with drainage and provides air spaces at the bottom of the pile.
  2. Next scatter a couple handfuls of loose garden soil over the top (this inoculates the pile with soil microbes).
  3. Alternate layers of green material (2-4 inches) with brown material (5-7 inches). Be sure to water each layer as you go, adding more water to the brown layers. You can add handfuls of soil or old compost in between layers as well, to introduce more microbes. It’s a good idea to add a layer of twigs in the middle of the pile to create air pockets for better aeration and prevent compaction. Use twigs in the compost pile the same way that you would use them to build a campfire – with alternating rows and columns that allow air to flow through easily.

*A general rule of thumb when layering: For every layer of nitrogen, add 3 times that amount in carbon material (in volume, not weight). If your pile is slimy or stinky, you need more carbon. If your pile is not heating up, you need more nitrogen.

Moisture

Those microbes need water to live, so keep your compost moist but not soaked. Water occasionally, or let rain do the job. You want it to be like a well wrung-out sponge. It’s best to keep your compost pile covered, so you have full control of the moisture content. Covering it will also help retain heat.

Aeration

Oxygen is so important for a healthy compost pile, so you may need to give your pile a quick turn with a pitchfork every once in a while. However, it is possible to skip the turning part if you use fluffy leaves or straw which will hold space for air. Without oxygen, your pile will go anaerobic and it will quickly smell like a garbage dump. Not cool for your neighbors! Always remember to bury your food scraps and add carbon to the top of the pile.

Size

Size does matter! If your pile isn’t big enough, it will not heat up. It needs at least 3 cubic feet of material. You don’t want it too big though, or you will break your back trying to turn it.

A closed bin is a good choice if you’re worried about the way your compost pile will look (or smell). You can easily make a container, or order one online. Use chicken wire or fencing to protect your bin from animals such as raccoons (or your own dog).

Compost tumblers are a good choice if you have limited space or close neighbors. They are designed to make hot composting easier to manage. We recommend an insulated tumbler, especially if you live in a colder climate.