Wood Chip Composting Time Calculator

Three months later: You keep staring at all those wood chips and think: Nothing’s happening in there. What’s going wrong?

This is what makes people quit on making compost from wood chips before they’ve given it a chance to get going: Nothing changes visibly. The pile just sits there looking like the day the arborist deliver it. But a wood chip isn’t a leaf mulch. It’s a densely structured piece of carbon designed to last, something that needs special conditions (conditions most backyarders don’t unwittingly provide) in order to break down.

Why Your Wood Chip Compost Is Not Working

Use the calculator above: once you enter your pile size, moisture content, and any other ingredient that contain nitrogen, the calculator will do the math for you. But knowing why the variables matter is what really converts waste into soil.

Everyone assumes that piling up some wood chips will do the trick. Nope. As always, the biggest problem is the C:N (carbon to nitrogen) ratio. Wood chips from raw wood are very high in carbon… Often sitting at a ratio of one hundred to one or higher. That means the wood needs nitrogen for microorganisms to break down the carbon, but if there’s no nitrogen, nothing happens; the breakdown slows to a crawl. Nitrogen is like the fuel that powers the carbon engine. No nitrogen? No heat. No life in the microbes. Stuck chips. That’s why all those recommendations to add manures or grass clippings or even coffee grounds aren’t optional, they’re essential to get things moving fast. With this tool, you can figure out how much of those so-called green ingredient you’ll need to reach that sweet spot where biology goes haywire.

Moisture is the other frequent cause of compost project failure. A pile may appear moist on the surface but be as dry as a bone inside (which happens if wood chips are used; they don’t absorb water well). You want something between fifty and sixty percent moisture (like a wrung out sponge). Less than that, and microbial action slows way down. More than that, and things get anaerobic, smelling foul and producing methane different than compost. Here’s where season comes into play again. Starting a pile in the humid spring, for instance, versus in the dry heat of high summer, affects the internal balance and causes varying rates of evaporation each day.

How big should your compost be? Surprisingly enough, this is an important factor when deciding if your heap will heat up. Piles less than one cubic yard are typically not hot enough (meaning they don’t rapidly break down lignin). This is because these small heaps aren’t able to retain heat well; they lose heat into the air around them before the decomposing organisms can produce more of their own. In contrast, larger heaps retains heat better, making them ideal environments for decomposition (especially anything more than three cubic yards). The catch: Large heaps take longer to aerate and turn, which means more work on your part. You’ll need to weigh size versus effort and go with what makes sense based off your tools and body.

Frequent turning gets confused with a job; it’s actually your friend. By bringing air into the mix, turning is the last component of this aerobic equation. If there’s no oxygen, all those lovely thermophilic bacteria will die out and be overgrown by their cooler, slower decomposing cousins. Yes, you can go many months without turning at all, but that will certainly slow things down. The prediction above assumes what level of “turning frequency” you choose (daily, weekly, whatever), and therefore gives you a reasonable timetable instead of a best-case scenario.

So here’s how it works: The end result won’t resemble the beginning ingredients. Depending on what you started with, there may be a big reduction in volume (sometimes as much as half of the original). But don’t worry; that is a good sign. The pile has shrunk because the air spaces dissapears. It is all settling down into an earthy, compact mass of black gold. After six months, if your heap remains light and fluffy, then it’s not working right. Most likely it’s too cold, too dry, or lacks nitrogen. Inserting a long prong into the heap will reveal whether it’s got any life left in it.

IT’S A gardening task that tests the limits of your patience: composting wood chips. It’s about planning ahead, and it takes time (you can’t hurry Mother Nature). If you get the balance correct, it rewards you with a stable, rich amendment. This improves soil structure and helps it hold nutrients and water better than even leaf mold can alone. In fact, over time, the chips degrade into that beautiful humus that holds onto nutrients and water so well. It is worth the wait.

All it takes is feeding the heap the proper ingredients, and providing it oxygen (a.k.a. It needs enough “air” to breathe. The basics: Start with that; then balance the carbon with nitrogen; don’t let it dry out; and let time take the rest of the load off. Your soil will reward you for the effort with that dark, fertile gold made from those stubborn chips.

You should of seen how much better it works once it gets going. This moddern process is naturaly the best way to make soil.