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DIY Compost for Your Best-Ever Garden

You don’t have to be an expert gardener or have a big yard to get started turning your kitchen waste into garden gold. Composting is one of the single best things you can do to create a healthy garden, and it’s easy once you get the hang of it. Here’s all you need to know to get started.

Composting by Della Chen

What is Compost?

This lush brown medium acts as fertilizer, insulates plants, suppresses weeds, and retains moisture. Compost is made up of organic matter (from plants and animals) that breaks down over time. There are many players in this process—animals, fungi, bugs, microbes, bacteria—all of whom play a role in the decomposition of organic matter resulting in compost.

How to Make Compost

There are two basic methods for making compost: hot and cold.

A hot compost pile produces finished compost (ready for garden use) more quickly, because the heat accelerates the process of breaking down the organic matter. Using the right mixture of carbon and nitrogen (that is, browns like dried leaves and greens like lawn clippings), the compost heats up by feeding on carbon. When the carbon eventually burns out, nitrogen-rich compounds are left behind.

Cold compost is created in the same way – just more slowly. It’s easier, too; with cold compost you don’t need to monitor the amount of greens and browns you add to a pile. Instead, you simply dig a hole in the ground and add vegetable food waste, as well as any green and brown yard waste, and then cover it up. Eventually, this pile of waste will become compost. (People often build back yard compost bins, but be forewarned that these bins may attract rodents and sometimes smell.)

Compost bins by Brie Williams

No yard? No problem!

In a small garden, or apartment, however, neither of these processes are really feasible. Vermiculture is a great resource for making compost at home in a very small space.

Vermiculture uses worms in a worm bin to break down food waste and bedding (slightly damp newspaper strips) into compost. Worms produce castings: worm manure, also called vermicompost. These castings are then collected and used on plants and in gardens as lush, nitrogen-dense fertilizer. Worms can eat half their weight in food waste every day. If you start with one pound of worms, count on their handling about a half a pound of kitchen scraps each day.

How to Create a Worm Bin

There are a number of options for worm bin containers, from pricey commercial bins with multiple trays to plastic storage bins or homemade bins. Read more about how to create your own worm bin from a plastic storage container.

The worms used in worm bins are not your garden earthworms, but a particular species—commonly called red worms or red wigglers—that would not survive for long in outdoor conditions. You can buy them locally or by mail order, or get some from a friend who already has a worm bin. You will need to keep worms at temperatures between 55 ̊F and 75 ̊F; this means you may need to bring the bin inside during cold winter months.

Worm Bin by Jason Donnelly

You can buy fancy plastic worm bins like this one. Photo by Jason Donnelly

Maintaining Your Worm Bin

A new worm bin starts slowly, so you should add food waste in small amounts at first and monitor how quickly the worms are able to process them. They may ignore foods they don’t like; if so, remove these scraps so they don’t rot. When you add food to the bin, lift some bedding up and put the scraps underneath to help minimize odors. Add scraps to a different part of the bin each time, so the worms have a chance to process the older scraps before more waste is piled over them.

Worms can get finicky. A few finely crushed eggshells provide grit to help them digest. Do not give the worms proteins, dairy, oil, or oily products like vegetables cooked in oil or fried potato chips. Instead, include only plant-based organic matter like vegetable and fruit scraps. I have seen many a worm ignore citrus peels, but you can try them. Worms also love coffee grounds, and you can include the paper filters. Grains (stale bread, tortillas, and so on) are OK too.

How to Harvest Your Compost

After a few months, the worm compost will likely appear dark brown, like finely crushed cookie crumbs. To harvest your compost and re-bed the bin, move the entire contents of the bin over to one side. On the other side, refill the area with a mound of fresh bedding. Add some new kitchen waste to the new bedding side and wait for the worms to migrate over. Once they do, remove or harvest the worm compost. Store any excess in a breathable container, or share with neighbors and friends. Top-dress your pots with a sprinkling of worm compost every six weeks or so. As worm castings are quite nutrient rich, don’t add too much too often or you run the risk of plant “burn” from over-fertilization.

Worms expel liquid as they break down your kitchen scraps. You can collect that liquid and add it directly to plants along with the vermicompost. Or add equal parts water to the worm “tea” and spray or water your plants with this solution. This also makes a great gift for any gardeners in your life.

What Can You Add to Your Compost Pile?

Browns (aka Carbon): dead leaves, woody prunings, straw/hay, pine needles, ash, newspaper, cardboard, corn cobs, dryer lint, sawdust or woodchips, shredded paper (avoid glossy paper and color inks), eggshells

Greens (aka Nitrogen): green leaves, grass clippings, plant cuttings (do not add diseased or invasive plants), fruit and vegetable scraps, chicken manure, coffee grinds, spent tea bags

What Shouldn’t You Compost?

Meat and bones or fish scraps, as both will attract pests, perennial weeds or invasive plants, non-organic banana peels and citrus peels (which may contain heavy pesticide residue).

Related: Why it matters where your food comes from


About Amy Pennington