Save time and avoid potential back pain by learning how to build a DIY compost tumbler.
Truth be told, our compost pile very rarely, if ever, gets turned. When it comes to the compost heap, my preferred method is to pile it up and let nature take its course, which it effectively does. Compost cures whether you turn the pile or not; it just happens at a slower pace when you leave it to nature alone. While this method of composting is easy on the back and takes little effort to maintain, it does take time for the process to complete — sometimes up to a year or more.
We still keep a compost pile, but for producing compost on the fast track, I prefer a compost tumbler. It’s an easy-to-use option for the busy gardener. The closed environment of this barrel-style tumbler makes it rodent-resistant, and when used correctly, you can create compost in eight to 10 weeks from start to finish. Besides, I’d rather turn a tumbler than toss and turn the compost with a manure fork any day.
Tips for Building a DIY Compost Tumbler
Choose a Container
Look for galvanized steel trash cans or plastic drums or barrels at your local home improvement store, or online sources for new or used containers. Large restaurant or food distributors are another source for food barrels.
You may already have a new or used plastic drum or rain barrel on hand. Just make sure that the container was used only for food or other nontoxic substances. You don’t want any hazardous materials or toxic residue to end up in your compost, and ultimately, your garden.
Keep materials in your DIY compost tumbler in balance.
The closed environment of your DIY compost tumbler is different than an open pile; think potted plant versus a plant in a terrarium. As such, it’s important to add at least 40 percent of high-carbon organic waste — brown materials — to ensure friable compost instead of a slimy and smelly mess. I prefer a 50/50 ratio — an equal mix of high-nitrogen organic waste (green materials) and high-carbon organic wastes (brown materials) every time you add materials to your compost tumbler.
Make it easy to maintain the proper green-to-brown ratio by keeping a bag of leaves, shredded newspaper or bale of straw near your composter. And a large bucket filled with topsoil gives easy access for when you add more materials to the compost tumbler.
Size matters when adding to your DIY compost tumbler.
It helps to break up, cut up, chop up, or shred anything that’s large or easily mats, such as tree branches, corn stalks, watermelon rinds, leaves, etc. You can leave them whole if you’d like — everything eventually decomposes — but you’ll speed up the process if the pieces are smaller.
Maintain Adequate Moisture
Your compost tumbler will maintain moisture more efficiently than compost in an open pile or compost bin. As such, the goal is to keep your materials slightly damp, like a well-wrung sponge.
You may not need to add any additional water depending on the weather, temperature, and location of your compost tumbler.
If the materials feel somewhat dry, add just enough water (a light misting is best) to keep materials moistened, but not wet. If the contents are wetter than a damp sponge, leave the lid open for a day or so to allow them to dry out. This will help accelerate the composting process without adding excess weight to the container.
Turn Up the Action
Turning the pile is easy with this DIY compost tumbler — just keep grabbing the handles and pulling downward. By turning the tumbler you will introduce air and redistribute the composting material with each spin.
The spinning action, on occasion, can force some of the organic material into some of the air holes.
Since this composter is designed with either 3/8- or 1/2-inch air holes rather than 1-inch air holes, this shouldn’t be an issue. Even so, it’s a good idea to check the air holes every now and then to make sure that none have become clogged by organic material inside the container.
Give the tumbler a spin every time you add organic matter. For faster compost, give it a few good turns from once a day to once a week. The frequency will depend on the outdoor temperature and size of materials being composted. Keep spinning the drum and your compost should be ready to use in 10 weeks or less.
How to Build a DIY Compost Tumbler
- Drill with 3/8-inch or 1/2-inch bit for drainage/aeration holes; and one bit large enough in diameter to accommodate the galvanized pipe
- Screwdriver, or drill with screwdriver bits
- Adjustable wrench
- Sturdy plastic drum or barrel with tight-fitting lid, or galvanized steel trash can with tight-fitting lid, between 30 and 55 gallons (for particulars, see “Tips for Building a DIY Compost Tumbler” above)
- Galvanized pipe (threaded both ends), 1 to 1-1/2 inches in diameter and 36 to 48 inches long (diameter and length will depend on the size of your container)
- 1- to 2-inch-diameter galvanized pipe caps (to match the diameter of your galvanized pipe)
- 2-by-4 lumber, 4 pieces with each piece cut to a length that is one-half the container’s height plus 2 feet. For example, a 55-gallon drum at 36 inches in height requires 4 pieces of 2-by-4, with each piece cut 42 inches long (36 divided by 2, plus 24 equals 42 inches).
- 2 sawhorse brackets and galvanized screws
- 2 bungee cords (needed only to secure a nonlocking lid)
- 2 handles with bolts and washers, for turning your composter
- Start by assembling the four pieces of 2-by-4 and sawhorse brackets to make two sawhorse halves. If needed, you can strengthen each side by attaching a cross member board or a triangle-shaped piece of plywood placed 6 inches below the top of the A-frame and 6 inches above the A-frame’s bottom.
- Measure and mark your container along its length halfway between the top and bottom. Make a similar mark on the opposite side. Through each mark, drill a hole that is large enough in diameter to accommodate the galvanized pipe you are going to use for the axle.
- Use a 3/8-inch or 1/2-inch bit to drill holes, spaced 4 to 6 inches apart, all around the container for aeration and drainage. Drill 12 to 15 holes in the container’s bottom, and a total of 6 to 10 rings of holes around the barrel. The goal is to create enough holes to allow excess moisture to seep out and keep air flowing freely through any materials that you add to the compost tumbler.
- Attach one handle about 6 inches below the top of your container. Attach the second handle on the opposite side about 6 inches above the bottom of your container.
- To assemble your compost tumbler, choose a level area where you want your composter to live and put the sawhorse halves in place. Insert the galvanized metal pipe through the two opposing center holes that you previously drilled in your container. Screw on the pipe caps. Place the container between the two sawhorse halves, top end up, and set in place so one end of each pipe sits on a sawhorse half.
- Fill the container with kitchen scraps, grass clippings, leaves, straw, garden trimmings and other organic materials. Moisten the compost materials, if needed, and toss in a few scoops of fresh topsoil every time you add more materials.
- Always make sure the lid is secure before turning your composter. If needed, you can use elastic bungee cords to secure a loose-fitting lid by stretching the cords across the top of the lid in a crisscross fashion and securing the hooks to the garbage handles. If your container lacks handles, secure each hook to one of the small aeration holes.
Kris Wetherbee lives and gardens in Oakland, Oregon, with her husband, Rick, and she wouldn’t trade her homemade compost tumbler for anything.