HOW TO MAKE GOOD COMPOST

Good compost should have a crumbly (but not dry) texture and should smell like the forest floor.

In my years of experimenting with ways to make compost, I’ve used different kinds of bins, tried trench composting and made old-fashioned compost piles at the family farm. These days, I use a rotating compost bin to turn organic waste into nutritious compost for my gardens.

What I’ve learned is that composting doesn’t need to be complicated or expensive, no matter how you do it. It can be done in four easy steps that I call my G.L.O.W. (greens, leaves, oxygen, water) method.

Greens

Kitchen scraps ready to be added to the compost.

Green waste includes kitchen scraps, yard waste and manure. It’s high in nitrogen, which helps speed decomposition. While there is no exact recipe for making compost, one part of the mixture should be greens.

I keep a storage pail under my kitchen sink to collect scraps such as banana peels, apple cores, vegetable skins, tea and coffee grounds and other kitchen waste. I also add eggshells, although they’re slower to break down.

Other green waste includes grass clippings, green plant trimmings and herbivore manure such as highly coveted chicken droppings. Take care to not add too many greens to the compost bin or it will start to smell like ammonia.

Leaves

Brown materials added to the compost include leaves and twigs.

Leaves and other brown materials can be mixed into green waste or layered on top. However you do it, beneficial micro-organisms such as fungi, bacteria, protozoa and other tiny soil creatures must then do their job of decomposing it into soil. Macro-organisms such as millipedes, earthworms, centipedes, snails and slugs help, too.

Tumblers and other compost bins that are off the ground and away from soil need a shovelful or two of finished compost to get the decomposition process started.

The joy of composting is that you don’t need to measure too carefully. Your brown and green mix will eventually decompose outdoors, even if you botch the recipe.

Oxygen

Using an aerator tool to turn the compost pile helps to incorporate air, which aids in its decomposition.

Just like us, the micro- and macro-organisms that break down the waste material need oxygen. There are several ways to add air to your compost heap.

When the weather cooperates, turn the pile regularly using a pitchfork. I use an aerator tool – an auger with a handle on one end and a retractable blade that opens when plunged into the compost pile. Some handy gardeners make their own auger using a sturdy stick, an old broom handle or a piece of rebar.

Finally, you can add air to the compost pile by elevating it. Simply layer the bottom with sticks and twigs followed by a layer of leaves or other brown waste and build from there.

Water

Adding a bit of rainwater to compost that has dried out.

Compost should be kept moist but not soaking wet. Aim for the consistency of a well-wrung sponge. If you let your pile get too dry, decomposition will slow. Add a bit of water to remedy this.

Conversely, if your compost pile is too moist, anaerobic bacterial will replace beneficial aerobic bacteria and you will notice a rotten-egg smell. Remedy this by adding more brown material such as dry leaves and shredded newspaper.

Let It Cook

An open compost pile in the back yard.

Backyard composters need heat. A sunny spot is useful, but not essential. My three composters are all designed differently but they all work efficiently in partial shade where less frequent watering is needed. No matter where you locate your compost bin, the contents will usually break down quickly during warm spells.

For easy access, especially during the winter months, locate your backyard composter close to the house and near the kitchen door, if possible.

What Not to Add

A spring-blooming hellebore benefits from having a bit of compost added to the soil that surrounds it.

It’s hard to ruin compost. Like the forest with its cycle of death, decay and new life, brown and green kitchen and garden waste gradually decomposes. It may take months or even a year or more, but eventually you’ll make good compost.

Nevertheless, there are some items that should never be added to the compost bin. Avoid adding fish, meat and dairy products that may attract animals such as raccoons and rats. Diseased plants can spread disease, even after they rot. Weed seeds can spread in compost unless temperatures are very high. Charcoal ash may contain harmful chemicals. Grease, oil and fat can cause a foul smell. Pet waste is also a no-no.

Making good compost is simple but it does require patience. Keep in mind that unfinished compost can rob nitrogen from the soil, so let the materials rot well.

When it’s ready to harvest, you can sift it (but it’s not necessary) and spread it on top of the soil around your plants. There’s no need to dig it in. Then sit back and watch your plants flourish.

Text and photos by Julianne Labreche

Julianne Labreche is a freelance writer and garden enthusiast who volunteers as a Master Gardener and Master Naturalist in Ottawa.