When integrating compost into your garden, you’ll want to consider which composting process best fits your needs. There are countless reasons people take an interest in composting. A few of the most common motivations include a desire to lessen their environmental impact, improve their garden soil’s nutrient availability, and, of course, for fun! Fall is a great time to start preparing compost for spring garden beds.
From Trash-Can To Treasure
Plenty of people will already have the makings of this unique composter lying around at home. The original concept was presented in the September/October 1976 issue of Heirloom Gardener’s sister publication, Mother Earth News, and differs from other compost bins that simply rest on top of the ground. This composter goes subterranean by sitting in a 15-inch-deep hole surrounded by soil. Holes drilled around the lower sides and in the bottom of the bin allow water to seep out, while allowing worms and other organisms to creep in. The secure lid keeps out unwanted critters. You can make this bin with plastic as well, if a metal can is unavailable.
Trash-Can Composter Materials:
- Galvanized metal trash
can with lid
- Drill bit, at least 1/4 inch
- Safety glasses
Suggested Trash-Can Compost Recipe:
- 1 shovelful mulch, wood chips, or straw
- 3 parts shredded leaves
- 1 part food scraps
- Turn the can upside down and drill 20 to 30 holes in the bottom of the can. This process creates metal shards, which you can easily brush away with a gloved hand.
- Drill 20 to 30 holes around the bottom sides of the can. Go about 15 inches up the can. The higher you go, the deeper the hole you have to dig.
- Choose a well-drained spot in your yard to dig the hole. Use the empty can to imprint the ground, giving you a guide to the needed width of the hole.
- Dig the hole. You can periodically dip the can into the hole to see how much deeper you need to go.
- After you’ve reached your desired depth, place the can into the hole and fill around the outside with soil.
- Place a shallow layer of wood chips or straw in the bottom of the can to improve drainage.
- Add your food scraps and cover them with leaves. Secure the lid. If you have especially persistent critter neighbors, you could further secure the lid with a bungee cord across the top hooked onto the handles.
- Trash-can composters need aeration just like other types of bins. The easiest tool to use in the tight space is the hand aerator. If you stop adding food scraps about a month before you harvest, you’ll have less work pulling out a nice batch of compost. Simply lift the can out of the ground (this may require two people) and empty it where you want to use the finished compost. Screen the finished material into a wheelbarrow if you desire a finer finished compost.
Leaf Bins: As Easy As One, Two, Tree
Building a leaf bin is pretty easy. It’ll probably take you more time to gather the supplies than to actually construct the bin. Depending on the annual bounty of leaves you expect in your yard, you may want to build multiple structures or a larger bin. A 3-foot-tall leaf bin with a 3-foot diameter will hold the same amount of leaves as five paper leaf bags. While a 3-foot-tall leaf bin with a 4-foot diameter will hold the same amount of leaves as nine paper leaf bags. Leaves will settle quickly in a leaf bin, usually shrinking to half their original volume in just a month or two. With any luck, a full leaf bin will make room for more leaves before the next time you have to rake. The following instructions are for building a 3-foot-diameter bin. For a 4-foot-diameter bin, you’ll need 12-1⁄2 feet of wire fencing, but the basic steps remain the same.
Leaf Bin Compost Materials:
- 10 feet of 3-foot-tall wire fencing (the fencing should have holes small enough to keep the leaves encased)
- Wire cutters
- Zip ties
- Safety glasses
- Tape measure
Suggested Leaf Bin Compost Recipe:
- 10 parts shredded leaves
- 1 part coffee grounds
- Measure out 10 feet of wire fencing. Galvanized steel is easy to work with and stays sturdy and straight in the backyard.
- Use wire cutters to cut the fencing as near the intersections as possible, so little metal spikes don’t snag your clothes or skin. Wear gloves, and cut carefully, because the metal can be sharp.
- Form the wire fencing into a circle 3 feet in diameter. The fencing will overlap and add strength to the final bin.
- Use zip ties to secure the overlapping fencing to itself.
- Place the bin where you want it, and fill it up with leaves.
- To harvest compost from a leaf bin, simply lift the bin, and scoop up your gorgeous compost. Soil scientists and gardeners refer to finished compost made mostly of leaves as “leaf mold.” Although leaf mold doesn’t have the high values of nitrogen and other nutrients that traditional compost contains, it has a fantastic texture that helps amend soils and improve water retention for your plants.
Unlock African Keyhole Gardens
Finished compost provides your garden with numerous benefits, but what if you could also reap benefits from your compost while the pile is decomposing? African keyhole gardens place composting in the center of a small-scale raised bed. As their name implies, African keyhole gardens originated in Africa as a way to intensively grow vegetables in a manner that retains moisture and reduces the need for watering. Anyone in a hot or dry climate will benefit from building one of these gardens, but raised garden beds offer benefits we can all appreciate. The plants in the bed benefit from the nutrient-rich runoff coming from the pile and the increase in macro- and microorganisms drawn by the compost. The compost benefits from the insulation of the bin and the shared organisms. Everyone is happy and everyone wins, including you.
Construction of African keyhole gardens is limited only by your imagination. Most gardeners building them use found or leftover materials, including bricks, rocks, and pavers. The key is to create a raised bed with a compost bin in the center. Ideally, the compost bin is made from wire or mesh, allowing easy transfer of moisture and organisms with the surrounding soil. Instead of creating a perfectly circular garden bed, notch the circle with a keyhole to give access to the compost bin in the center. That way you can easily walk up to the compost and deposit materials without needing to reach over a garden bed.
African Keyhole Materials:
- Sharp shovel
- String or measuring tool
- Compost bin for center (metal mesh works well)
- Material for outside wall (brick, stone, etc.)
Suggested African Keyhole Garden Compost Recipe:
- 6 parts straw or shredded leaves
- 1 part manure and bedding
- 1 part food scraps
- 1 part green plant trimmings
- First, clear an area for the bed and measure two circles. The inner circle, or bin, will be the composting area and should measure between 1 and 3 feet in diameter. The outer circle should measure 6 feet in diameter.
- Notch the outer circle with a path large enough for you to access the compost in the center.
- Create the compost basket or bin. A simple wire mesh bin such as the leaf bin, on Page 60, works perfectly. I’ve seen people in Uganda expertly weave the inner compost basket from strong bamboo-like poles and bendable branches. Use materials to which you have easy access. Remember that soil will surround this bin, so it needs to be strong enough to withstand that weight. If you use wire mesh, reinforce the mesh with vertical pieces of wood, or loop the mesh into multiple layers to increase the strength.
- After you build a sturdy bin at the center of your African keyhole garden, build the outside perimeter of your garden. As seen in the illustration above, you can use bricks, stones, pavers, or pretty much any material you can stack in a circle to create a bed. I’ve even seen bed perimeters made out of wine and beer bottles set in mortar (a resourceful way to use a potentially plentiful material).
- Fill the center compost bin with material to increase its resistance to the forces of the soil that will surround it. You can add all the same materials you’d add to a regular backyard composting structure.
- Fill in the surrounding bed with soil and compost. Often, builders of African keyhole gardens line the bottom and sides of the bed with a thick layer of cardboard or other water-resistant material before adding soil. This layer helps hold in water in hot, dry climates but may be unnecessary in temperate regions.
- Plant what your heart desires. Many African keyhole gardens contain vegetables, but you could plant flowers, herbs, or any smaller landscaping plant you choose. When the bed needs watering, water the center compost bin and allow the water to trickle down and throughout to the rest of the bed.
- Some African keyhole gardens have modest walls, while others are 3 or more feet tall. The height depends on your landscape and resources. A taller perimeter wall will allow you to fill the bed with more soil and reap more benefit from the interior compost bin.
- Depending on the depth of your African keyhole garden bed, you’ll occasionally need to dig out the finished compost from the inner bin. For most setups, digging out the material once per year will prove sufficient. You’ll only need to ensure you have enough space to continue adding compostables.
Food Scraps Benefit From Burial
Food scraps — such as banana peels, old broccoli, and stale bread — are a fantastic source of nitrogen to complement the dry, carbon-rich leaves in your compost. Readily available in every kitchen and with little other use (unless you keep chickens), food scraps also add water and additional microorganisms to your compost. The most important step in adding food scraps to your compost is to bury your food scraps.
As they decompose, food scraps can start to smell, attracting critters to the bin. They can also attract flies that will lay eggs and create pesky swarms every time you lift the lid. To avoid odors, animals, and flies, all you have to do is bury your food scraps in your pile or cover them with additional leaves.
You can effectively bury your food scraps by having a pile of leaves set aside for the sole purpose of throwing them on top of newly deposited food scraps. Alternatively, use a hand trowel to lift up a layer in the pile and tuck your food scraps under a blanket of leaves and other compost. Either way, you shouldn’t be able to see the food scraps once buried. Fruit flies won’t burrow down into the leaves to lay eggs, and the leaves will act as a scent barrier to foraging animals.
Michelle Balz is a long-time backyard composter with a passion for reducing our impact on the planet. She spends her days writing laid-back advice for home composters in the Confessions of a Composter blog, teaching classes on backyard composting, and learning everything she can about composting, recycling, reusing, and waste reduction.
Excerpted with permission from Composting for a New Generation: Latest Techniques for the Bin and Beyond by Michelle Balz, published by Cool Springs Press, 2017.