What is Compost? How Can I Use it In My Garden?

Whether you are new to gardening or an expert green thumb, you’ve probably heard how compost can enhance your garden, but what is compost exactly?

The term “compost" is a term for decomposed organic matter that undergoes physical and chemical changes. In its original form, compost usually begins as garden refuse, food scraps, and/or animal manure layered in a pile. As the organic matter decays, various microbes and invertebrates – bacteria and fungi – break down the matter, changing its physical and chemical properties.

You might think it would smell – but it doesn’t. Properly maintained compost will neither smell nor look like “rotten” food. It will have an earthy smell and begin to turn black/dark brown.

In this article, we will cover various aspects of composting, from how to do it to why to do it.

With numerous reasons to use it – as well as ways to prepare compost -- you’ll be bragging to friends about your new skills in no time!

How Do I Make Compost?

There are three basic steps to creating good compost: 1.) create a blend of dry and wet organic materials, 2.) add air and water, and 3.) keep piling it up to the size of your liking!

Step 1: Layer Dry and Wet Organic Materials

For your compost to work properly - and NOT stink - you need a carbon to nitrogen ratio of 30:1 (for every 30 parts carbon, 1 part nitrogen). This just broadly means you want a mix of dry and wet materials (dried leaves and wet food scraps, for example)

Why so much carbon?

Well, most decomposing is done by microbes - bacteria and fungi. While these microbes do need some nitrogen to produce energy, they get most of their energy by breaking down carbon compounds. That’s why the ratio is so important. But don’t be discouraged by hitting the ratio exactly. It’s actually quite easy to approximate.

Carbon Materials: dried leaves, dried grass clippings, wood chips, sawdust, paper, and even straw. While straw is a great material high in carbon, do not confuse it with hay, which will seed in your compost and may produce too much nitrogen.

Nitrogen Materials: food scraps, fresh grass cuttings, fresh garden trimmings, green leaves, and animal manure.

Carbon Layer

Nitrogen Layer

Here is an easy pattern to follow:

Carbon Layer:     2” Dried Leaves / Wood Shavings / Straw

Nitrogen Layer:  3” Food Scraps

Carbon Layer:     2” Dried Leaves / Wood Shavings / Straw

Nitrogen Layer:  4” Animal Manure

Carbon Layer:     2” Dried Leaves / Wood Shavings / Straw

Nitrogen Layer: 4” Green Garden Refuse

Carbon Layer:     2” Dried Leaves / Wood Shavings / Straw

A good rule of thumb is dry, old or browning materials are carbon rich, and, if it’s green or has a lot of moisture, it is nitrogen rich. If you’ve never composted before, we recommend avoiding anything meat- or dairy-related.

It’s good practice to sprinkle a thin layer of dirt into the compost every few layers. If any nutrients are missing in the layers you’ve compiled, the microbes should be able to find them in the thin layers of dirt.

Step 2: Add Air and Water

Just like carbon and nitrogen, oxygen and moisture are key to a successful compost pile. If your compost becomes too dry, you can give it a quick hose to replenish its water content.

Water acts as a thermal regulator and will help your compost pile maintain its temperature. Your pile should be damp, but not sopping wet. It’s good practice to wet your pile every few layers as you build.

Most large compost piles are able to hold on to moisture, but if your pile is smaller, it may dry out quickly. Keep an eye on it and give it a quick hose if it appears dry.

Oxygen levels go hand in hand with moisture levels. As the air inside the compost pile heats, it rises up and out of the pile, pulling new air into your compost from below. This process is called convection. Adequate moisture levels will maintain the internal temperature of your compost pile and aid its air/oxygen flow.

If moisture levels are too high, the pathways around particles in your compost will be clogged with water and prevent airflow from happening naturally. When your pile cannot get enough oxygen into it, microbial activity will drop and your compost pile can get a bit smelly.

Step 3: Keep Piling Your Compost!.. Until It’s About 3’X3’

You can make your compost pile any size or shape you like, but there are some factors to be aware of before you start your pile so that the process is easier on you.

We recommend you don’t make it so high that you find it difficult to layer, mix or turn. Most gardeners keep their pile around 3-4' tall.

In order to allow oxygen to reach the center of the pile, we recommend that the width not be more than 3’. Whatever size you pick, just be sure you’re able to reach the center with a cultivator or shovel. You’ll occasionally want to stir it up. A good pile size to start with is around 3’x3’.

If your pile is smaller, keeping a stable temperature will be more challenging, but not impossible. Just keep an eye on it.

As with the size of your pile, the size of your compost materials can make a difference in how they decompose. The smaller the materials, the quicker they will decompose.

Keep in mind that the smaller your materials are, the easier they will be to compact, limiting air flow, so it might be a good idea to mix some larger materials with smaller ones to avoid this.

Step 4: Use Your Compost!

Once the decomposition process completes - within 2-3 months - you’ll be left with a fluffy, dark, rich soil. It will be fine in texture and blackish in color.

Mix it in your garden bed, or just sprinkle it on top to let the nutrients trickle down into your garden soil. Better yet, if you haven’t transplanted your seeds, put some compost at the bottom of each planter hole. We like to surround the plants with lots of compost — it’s the best fertilizer you’ll ever have AND it’s organic!

As your compost pile produces more and more compost, just keep mixing it until you’re ready to use it. It doesn’t go bad, so there’s no rush to use it immediately.

One cautionary tip: don’t use compost as a replacement for soil when growing seedlings. Seedlings are very vulnerable to nitrogen, so you could risk killing them. Use regular garden soil in your Sili-Seedlings, then once you transplant them, add your compost!

Composting is so Important!

In a lot of ways, compost can seem gross, but when you get down to it, the activity going on in a compost pile is the same activity you want to see in healthy soil - bacteria and fungi breaking down refuse into ready-to-use nutrients for plants.

Often times our garden soil can become tired, abused and depleted, which creates a poor environment for growing plants -- this is why we add compost to our gardens. It's like inoculating your soil with life.

Adding and amending your garden with compost not only introduces vital nutrients plants need, but it introduces it to microbe and insect populations that might not be flourishing in your soil as they should.