Closed composting can reduce risks of roaming pests on small lots
Updated: Sep 25, 2019
As the attendee at a soil health class last summer, I listened in disgust as a local urban farmer chastised a woman‘s question about closed composting. He tormented, ”Eww, bugs,” while she sat both stunned and hurt. Having recently switched to a tumbling composter myself, I knew there was one very good reason to utilize this method on small lots... pests and how dangerously close to the home they can be drawn by kitchen scraps.
Despite their place in fairy tails, I've never romanticized about mice and I’m sure that farmer has no love lost on them either. Growing up in an old, wood-framed farmhouse, I was no Cinderella and they didn't help with chores. Rather, their gnawing through the walls would keep me up at night and inevitably, they found the fibers of my favorite clothes the perfect material to chew for their nests. Nowadays they live in my yard, nibbling the tops of young plants, having been lured in during the winter by food scraps in my open compost.
Admittedly, open composting is far easier. With a year's experience using my tumbling composter, I can attest that like everything in life the more control you seek, the more you have to micromanage. I'm not a fan of micromanaging and at present, anyone opening my composter would be met with an awful whiff of foul, anaerobic waste. I have a split tumbler, allowing one side to cure while materials are added to the other but with rainfall totals for the last 30 days exceeding 13 inches, both sides are saturated and need some TLC. There are also bugs, including a couple roaches, in the tumbler. I had not seen roaches before the heavy rains so I suspect flooding forced them to locate a new food source and given the out-of-balance condition of the materials in my composter, it was as good as any.
Bugs are something you'll have to deal with regardless of your composting method. A tumbling composter probably does the best job of preventing rodent attacks on the device because these are often raised at least a little bit off the ground. I use one lifted off the ground by two metal legs and recommend something similar to prevent mice. I fear that composters placed on the ground would be susceptible to starving rodents chewing their way through the outer walls. They can. I've seen them chew through things much thicker. If mice aren't a concern, a composter that sits on the ground would be fine. However, bugs will still visit no matter which type of composter is used.
There are some tricks to closed composting but in my opinion it's easy to learn how to do it right. It's pretty obvious when the materials are off balance. Too much green and its smelly, too much brown and nothing is happening. My tumbling composter does seem to work more quickly than open composting likely because it is black meaning it gets much hotter under sunlight, and that heat is trapped.
That said, there are some important things I think anyone interested in a tumbling or fully closed composter should know:
Having a double chamber is important. This allows one side to cook while materials can still be added to the other side. This allows for having a steady supply of compost because the cooking side needs to be left alone for two weeks to a month. Continuing to add to it will only delay the time until it's ready.
Routine turning incorporates the air needed for bacteria to work their magic. Just like turning open compost with a pitchfork or shovel is necessary, turning a tumbling composter is as well. This is one of the ways a tumbling system requires more micromanaging than open compost because it needs to be turned/tumbled about two or three times per week.
A small composter can be ideal because it is easier to turn and has a smaller footprint. I have a 5 cu. ft composter and it churns out quite a bit of compost but in small batches. It's footprint is about four square feet. A friend has a very large tumbler, one that looks like an industrial sized barrel complete with a handle and large gear for turning. She's had it close to 10 years and has made one batch of compost. The reasons where multiple: it took a long time to fill and required large loads material, it was difficult to turn even though it is gear driven, and because it's so big and ugly it was relegated to hidden corner where it's mostly forgotten about.
The composter should have adjustable vents. I discovered one side of my composter was cooking much faster than the other. The reason, one side was vented while the vents on the slower cooking side were closed. It defied my logic because I would have assumed the opposite, that closed meant more heat which would mean cooking faster. I learned from experience that circulation plays an important role. All that bacteria needs fresh air!
Keep the tumbler away from any structure to prevent mice, roaches or flies from possibly finding their way inside. Sometimes the compost will be like mine is right now, anaerobic, and that's okay. It's a small problem when it isn't made worse by drawing pests into the home.
Balance doesn't equal 50/50 in one of these systems. The "half greens/half browns" rule is based on weight not volume. I'm not clear on the science behind why, but I've found in a tumbling composter about 1/3 greens to 2/3 browns is the best balance.
Compost activator really is required in every batch. Some open compost users will scoff at this product and question whether the microbes actually work or are even alive. It's similar to how people question the benefits of probiotics. In my experience, they work, and a scoop of old compost left behind when the composter is emptied isn't enough. I've had far better results using a compost activator and recommend it for any tumbler or closed system.
If you're using or plan to use a tumbling composter, be sure to follow my blog. I have lots of content planned and you'll get to come along with me as I continue learning. Along the way I'll be sharing tips and techniques for this composting niche.
This is a link to the tumbling composter I use and love. I'll talk more about what makes it great in future posts.
I use Jobe's Organic Compost Starter as the activator/inoculant.
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