Your Guide On How to Make a Compost Bin
A compost bin is a smart way to put food scraps to good use—and no, it won't smell up your apartment.
When it comes to food, everyone's trying to make the most of what they have right now, avoiding frequent trips to the grocery store (or subscribing to grocery delivery services), getting creative with pantry staples, and trying to cut back on food waste. Even after you've taken your food scraps as far as they can reasonably go from an edible perspective (i.e., making "trash cocktails" out of citrus peels or leftover vegetable skins), you can go one step further, using them in compost rather than throwing them in the garbage.
So what is compost, exactly? It's basically a mixture of decayed organic matter that's used for fertilizing and conditioning land—or on a smaller level, your garden or potted plants, according to the Environmental Protection Agency (EPA). It's easier than it sounds to make a compost bin, even if you're limited on space. And no, it won't end up smelling up your home. Here's how composting can be beneficial, how to make a compost bin, and how to ultimately use your compost.
The Benefits of Using Compost On Plants
Whether you're already a seasoned gardener with a green thumb or simply trying to keep your first house fern alive, compost is beneficial to all plants because it builds up the nutrients in the soil. "Just like we eat yogurt or kimchi, which help inoculate our guts with beneficial bacteria, adding compost to your soil inoculates it with billions of microorganisms that help your plants remain healthy," explains Tucker Taylor, the master culinary gardener at Kendall-Jackson Wine Estates & Gardens in Sonoma, California. Taylor says he regularly makes and uses compost across the gardens he manages.
What Exactly Is Compost, Really?
There are three main components of compost: water, nitrogen, and carbon, the latter of which are referred to as "greens" and "browns," respectively, says Jeremy Walters, sustainability ambassador for Republic Services, one of the largest recycling collectors in the United States. You get nitrogen from greens like fruit and vegetable scraps, grass clippings, and coffee grounds, and carbon from browns like paper, cardboard, and dead leaves or twigs. Your compost should have equal amounts of greens—which provide nutrients and some moisture for all of the material to break down—to browns—which absorb excess moisture, help maintain the compost's structure, and provide energy to the microorganisms that break it all down, according to the Cornell Waste Management Institute.
Here are the best materials to add to your compost bin, according to Walters:
- Vegetable peelings (green)
- Fruit peelings (green)
- Grains (green)
- Eggshells (rinsed) (green)
- Paper towels (brown)
- Cardboard (brown)
- Newspaper (brown)
- Fabric (cotton, wool, or silk in small pieces) (brown)
- Coffee grounds or filters (greens)
- Used tea bags (greens)
However, there are a few things you should avoid putting in your compost if you don't want an odiferous bin, think: onions, garlic, and citrus peels. The general consensus, according to the experts, is that you should also keep out dairy or meat scraps to avoid a stinky situation when using an indoor compost bin. If you're following these guidelines and still finding that your compost has an odor, it's an indicator that you need more brown materials to balance out the nitrogen-rich green materials, so try adding more newspaper or some dry leaves, suggests Walters.
How to Make a Compost Bin
Before you get started with a compost bin, consider your location. You'll want to use a different composting method if you're making it indoors or outdoors.
If you're in fact able to compost outdoors, a tumbler—which looks like a giant cylinder on a stand, that you can spin vs. that cute tumbler that keeps your hydrated—is a good option when you have more space to work with, says Walters. Because they're sealed, they won't smell or attract pests. Plus, they don't require the use of worms (see more below about indoor composting) because the heat from being sealed and direct sunlight helps the compost break down on its own. You can find a variety of outdoor composting tumblers for sale online, such as this Tumbling Composter with Two Chambers at Home Depot (Buy It, $91, homedepot.com).
If you're composting indoors, you can purchase a compost bin such as this Bamboo Compost Bin (Buy It, $40, food52.com). Or if you're feeling ambitious and want to build your own outdoor compost bin from scratch, the EPA offers step-by-step guidelines on its website. You'll want to set your compost bin up wherever you have space: in the kitchen, under a table, in a closet, the list goes on. (No, it does not need to go in the kitchen and it shouldn't smell.)
1. Set the foundation.
Once you've found a home for your compost bin inside, you can start layering the components by first lining the bottom of the bin with newspaper and a few inches of potting soil. What comes next, however, depends on the type of composting.
2. Begin layering your compost (with or without worms).
Not a fan of crawly things? (You'll understand soon.) Then, after lining the bottom of the compost bin with newspaper and some soil, add a layer of browns. Next, create a "well or depression" in the browns layer for the greens, according to the Cornell Waste Management Institute. Cover with another layer of browns so no food is showing. Continue adding layers of greens and browns depending on your bin's size and slightly moisten with water. Skip step 3.
However, if you can get over the ick-factor, Walters recommends vermicomposting for small-space indoor composting, which involves adding worms to your greens and browns to more efficiently convert food scraps into usable nutrients and minerals for plants in the soil. While you don't have to include worms in your composting process, the decomposition process might take longer and produce more of a smell (because the wiggly creatures eat the odorous bacteria), according to Igor Lochert, president of The Worm Farm Portland in Newberg, Oregon, which produces composting products.
"If you're thinking 'Worms… inside?' rest assured worms are slow and have very little interest in taking up residence on your couch," he adds. They'll want to stay in the mealy food scraps you're providing in the compost bin and are very unlikely to escape from the container. Although, best to keep the lid on the container to ensure they stay put and peace of mind (because, ew, worms).
Vermicomposting is effective at converting food scraps into usable nutrients for plants for a couple of reasons, says Lochert. First, worms turn the soil by moving through it, leaving behind castings (manure) and cocoons (eggs). It sounds gross, but those castings left behind are high in nutrients, which can help the compost break down. Second, worms help aerate the soil just by moving through it—crucial to having healthy soil in the compost bin and ultimately when added to your plants. (See also: Small Tweaks to Effortlessly Help the Environment)
The easiest way to do vermicomposting is to buy a bin kit online or from your local hardware store or nursery, such as the 5-Tray Worm Composting Kit (Buy It, $90, wayfair.com). You'll also need to purchase its tenants—worms—to get started. The best type of worm to add to compost is a variety called red wrigglers because they consume waste quickly, but typical earthworms do the job, too, according to the EPA. As for how many little guys? While there's no hard-and-fast rule, beginners with smaller indoor compost bins should start with about 1 cup of worms per gallon of compost, says Lochert.
3. Add your food scraps.
Although it might be tempting to toss your veggie shavings into the compost bin right after making a salad for dinner, don't. Instead, save those scraps and any other food remains in a lidded container in the fridge, only adding them to the compost bin once a week.
When you have a full container of food scraps and are ready to add them to the bin, first throw in a small handful of moist shredded paper (really any kind of paper works, but the EPA recommends avoiding heavy, shiny, or colored varieties, as they won't break down as easily), then add the scraps on top of the paper. Cover all the food scraps with more paper and more dirt or potting soil, as exposed food can attract fruit flies. Of course, securing the bin's lid is also essential to fighting any potential flies. If you check your compost the following week and find that worms have not eaten a certain type of scrap (i.e., a potato rind), remove it or try cutting it up into smaller pieces before adding back to the indoor compost bin. The greens part of the compost should be providing enough moisture content, so you shouldn't need to add any extra water to the mixture. (Related: Should You Join Your Local CSA Farm Share?)
How to Use Compost
If you're feeding the compost correctly week to week (meaning: regularly adding food scraps to the bin), it should be ready to nurture your plants in about 90 days, says Amy Padolk, director of education for Fairchild Tropical Botanic Garden in Coral Gables, Florida. "Compost is ready to be used when it looks, feels, and smells like rich dark earth, has a crumbly soil at the top, and the original organic material [is] no longer recognizable," she adds. After you achieve all of these things, you should add about 30 to 50 percent compost to your soil blend for plants in containers or raised beds. For outdoor plants, you can shovel or sprinkle about 1/2-inch-thick layer of compost around the stems and planting beds, explains Padolk.
How to Use Compost If You Don't Garden
About 94 percent of the food that's thrown away ends up in landfills or combustion facilities, contributing to increasing amounts of methane gas (an ozone-damaging greenhouse gas), according to the EPA. So, by taking these easy, eco-friendly steps, you can help reduce methane emissions from landfills and lower your carbon footprint. So if you want to help, but don't have the need for all this compost you're creating, many areas have composting subscriptions where, for a small fee, companies like The Urban Canopy or Healthy Soil Compost can deliver a bucket that you can fill with food scraps, and then they'll collect the bucket once it's full, says Ashlee Piper, a sustainability expert and author of Give a Sh*t: Do Good. Live Better. Save the Planet. Check for composting companies in your local area to see what services are available near you.
You can also freeze your food scraps and donate them to your local farmer's market when you've reached critical mass. "Many markets and vendors will take food scraps so they can make their own compost for their crops," says Piper. "But always call ahead [to be sure] to prevent walking the town with a bag of soggy scraps." (Pro tip: If you live in New York City, Grow NYC has a list of food scrap drop-off sites here.)
Of course, you can always make your own indoor compost and share it with friends or family who have more outdoor space, if you don't have an area on which to spread it yourself. They—and their plants—will surely be appreciative.