If you've wanted to try at-home composting but felt intimidated, you're not alone! There are a lot of gardeners out there with complex composting setups and methodologies, but — as is the case with many things — just because it can be complicated doesn't mean it has to be. Whatever space, time, and energy you have to devote to your composting efforts, the fundamentals don't change. (And even apartment gardeners can get in on the action!) Keep reading, and we'll show you how composting can be a surprisingly easy, environmentally friendly way to improve the health of your garden while reducing waste.
The health of any garden starts and ends with the soil, and compost is one of the simplest and best ways to "feed" our soil and invest in its long-term health. The added organic matter from compost enhances not only the nutrient content of the soil, but its structure, too, allowing it to simultaneously hold more water and drain more easily. (This is especially important for Portland gardeners given the clay soils most of us have inherited.)
Composting harnesses the science of decomposition to efficiently transform organic materials that would otherwise go to waste — food scraps, yard debris, leaves, etc. — into dark, crumbly, nutrient-rich soil we can use in our gardens. While all of these things would eventually break down if simply left to rot, by creating favorable living conditions for the bacteria and fungi responsible for decomposition, we can speed up the process dramatically. All these microorganisms require is oxygen, moisture, warmth, and food — specifically, carbon and nitrogen.
Leaves, straw, wood, and shredded paper are all high in carbon, and in the composting world are referred to as "brown" materials. So-called "green" materials, by comparison, are high in nitrogen and include things like grass clippings and fruit and vegetable scraps. We need both for a compost pile, but generally you want to have more browns than greens — roughly three times more, although the ratio doesn't have to be exact. Some people layer these materials, while others don't. Feel free to experiment and see what works for you! The important thing is to make sure that your compost pile stays just barely damp, and that you occasionally "turn" the pile to aerate it. Too much moisture and too little oxygen will encourage anaerobic microorganisms to flourish, which will slow or stop the decomposition process, as well as generate unpleasant odors. (If this happens to you, see our troubleshooting section below.)
If you're getting caught up on the details of ratios and timing, it's good to remember: Decomposition happens all on its own, so even if we don't get everything exactly right, our pile will still eventually yield compost — it just may take longer!
1. The Traditional (Easy) Way
Traditional composting doesn't have to be complicated. At its simplest, it involves creating a pile in a designated corner of your yard, or finding room for a bin that can hold your compost-in-progress. You want to ensure your receptacle is large enough to hold the amount of organic waste you generate — or, alternately, the amount of waste you plan to compost. It can be large or small, and you can also have more than one! Some people prefer a multi-bin setup to move compost between different bins as they turn it over. We have a few ready-made options at the Farm, but you can also look up plans to build your own.
Whatever your setup, putting it in a sunny location will help keep it warm so that our community of decomposers stays happy. You will want to add your browns and greens in a 3:1 ratio and turn the pile every few weeks. If the compost appears dry, add water to maintain the moisture level. Composting this way can take several months to a year, but when the compost has fully decomposed, it will have a dark, crumbly texture and an earthy smell, at which point it can be used in your garden as a mulch or soil amendment.
One way to speed up the traditional composting process is by using a rotating drum or bin that eliminates the need for manual turning. However, it's important to note that "tumbler composting" does require more regular monitoring, and production is limited to the size of your drum.
2. Hot Composting
Temperature plays a role in the composting process at any scale, and a compost pile will naturally rise in temperature as the decomposition process takes place. But he degree to which this occurs will dictate what types of materials you should be putting in your compost pile, and how fast they will break down. Home composting typically reaches a temperature range of 90 to 160ºF, with smaller setups generating relatively less heat. While temperatures above 100ºF are sufficient to break down easily-decomposable materials such as kitchen scraps and grass clippings, in order to break down tougher materials like woody debris, weed seeds, and temperature-sensitive plant pathogens, your compost will have to reach temperatures between 140 and 160ºF.
This is where hot composting comes into play! The methodology is the same as traditional composting, but by paying closer attention to the size and position of our composting pile, we can speed up the composting process and make it more effective. Generally speaking, you will want a larger pile of at least four feet wide and high to allow the center to heat up sufficiently. (A sunny location also helps!) A compost thermometer can help you to measure the internal temperature at different depths of the pile, or you can judge it by feel. If the temperature is too low, you can add more nitrogen-rich materials like grass clippings to increase microbial activity. If the temperature is too high, you can turn the pile to improve aeration and reduce heat buildup.
3. Vermicomposting (Worm Bins!)
Although traditional composting can take place on a smaller scale, there is another method that is truly small-space friendly, and can even work indoors! Instead of employing microorganisms to break down organic waste into nutrient-rich soil, vermicomposting uses worms. They don't require much space, living happily in a container small enough to fit under your kitchen sink! Red wriggler worms (Eisenia fetida) are perfect for the task, and you'll find them at the Nursery in the spring and fall alongside our other beneficial insects. They consume kitchen scraps and, in return, produce nutrient-rich vermicompost (a.k.a. worm castings) which can be harvested from the bottom of the bin every few months and used just like you would regular compost.
The ideal worm bin is a shallow container between 8 and 16 inches deep, with ventilation and drainage holes on the bottom and sides. (A tray placed underneath will help to collect any excess moisture!) This container should be filled about three-fourths of the way with a suitable bedding material like shredded newspaper or cardboard, brown leaves, straw, or coconut coir — plus a bit of grit like crushed eggshells, sand, or dirt. It's important to keep this bedding moist so that your worms can thrive! And while your worm bin can be located either inside or out, red wriggler worms aren't particularly tolerant of temperature extremes, so it's best to place outdoor bins in a protected, shady location and relocate them either indoors or to the garage when temperatures drop below freezing.
A worm bin can handle about a quart of fruit and vegetable scraps per square foot in a given week, which can be buried in different locations each time you add them to the bin. (Coffee grounds and loose tea leaves are also acceptable.) Although you have fewer inputs, a worm bin is an easy way to compost without the same level of investment as a typical composting setup.
- Eco Master Compost Bin: We've found this style of compost bin to be effective for many home gardeners who don't want to dedicate a whole corner of their garden to a compost heap! It holds 79 gallons of organic material and features an opening a flap the bottom to remove finished compost from, plus a lid to keep critters out.
- Compost Thermometer: It's good to know how much heat your compost pile is generating to help you decide whether you're going to turn your pile or adjust its contents — especially if you're hot composting! A compost thermometer is just the tool for the job, because it allows you to gauge the temperature at different depths.
- Farm Straw: During the summer, our gardens tend to produce a lot more wet, green materials than dry, brown ones. Straw is an easy way to make sure your compost has enough carbon-rich browns to balance out those nitrogen-rich greens.
- Bloom Collapsible Garden Bag: You'll need something to move yard debris to your compost pile, and we've found these collapsible garden bags to be a great tool for doing just that — and when they're not in use, they fold away for easy storage.
- Kenkashi Compost Microbes: If you're composting in a small space and/or on a quick turnaround, you can jump-start the microbial action in your compost with an inoculated medium like this one from Kenkashi.
- Red Wriggler Worms: Perfect for your worm bin, these little guys are composting powerhouses, helping to cycle nutrients by breaking down kitchen scraps.
- E.B. Stone Compost Maker: If you have a lot of dry, brown materials — for instance, during leaf season — you can use this nitrogen-rich blend from E.B. Stone as a supplement to the greens you have on hand to ensure that your compost has the right mix of nutrients to feed the microbial life that will help to break down your compost pile. Plus, it provides an added boost of nutrition for your plants when you go to use your compost.
- E.B. Stone Finished Planting Compost: If all else fails, we have finished compost at the ready!
White growth: You may see a white fluffy mold growing – it’s harmless and probably means your compost is too wet or hot. Add in more dry material and give it a good turn. Make sure it’s getting enough air ventilation
Lack of breakdown: If your scraps are too large, they will take longer to break down. Try to cut down the scraps as small as you can.
Foul odors: Compost should smell earthy, but not rotten! Your compost is probably too wet and has too many greens. Try adding in some more browns and give your compost a good turn.
Too dry: You may have too much brown material or heat may be dehydrating your compost. Spray your pile with a bit of water and consider adding in more greens.
Additional Composting Resources
- Check out composting tips and how-tos from Metro.
- Find a list of what not to compost.
- Locate neighbors who compost and might be willing to add your compost to their own — a good resource for apartment/condo dwellers.
At Cornell Farm, we care about the health of our soil, which is why we carry a variety of products to empower you to create your own compost, including compost starter, compost bins, compost-turning tools, and red wriggler worms to help you start your own worm bin. If you can't produce enough compost to meet your own needs, we also offer high-quality compost from E.B. Stone that offers all the same garden benefits as homeade compost, in addition to an all-organic array of planet-friendly fertilizers.