If you’re like me, you probably create a good deal of sawdust and wood shavings in your workshop. Making compost is a great way to recycle the sawdust and wood shavings you create. It’s great for your garden or lawn, and it’ll help you feel more Earth friendly, too!
What It Is and What It Isn’t
Compost, the other “black gold,” is a mixture of organic materials left to decompose over time. It makes great mulch, and can be mixed with soil as a natural fertilizer. It’s great for either sandy or clay soils, because it helps to more evenly balance the soil’s texture and nutritional value (for plants, that is).
Done right, composting your sawdust or other woodworking shop waste is not smelly or unsightly, and it neither attracts pests nor distracts neighbors. Chances are your neighbors won’t even know you’re doing it until they start seeing your gardens or lawn flourish in the spring.
Composting Basics
The composting process requires a good mixture of nitrogen-rich (typically called “green”) and carbon-rich (typically called “brown”) organic materials. Think of nitrogen-rich materials as most things that are still green or still retain some moisture, such as banana peels, grass clippings, and the broccoli your kids wouldn’t eat. Think of carbon-rich materials as most things that are brown and dry, like sawdust, shredded paper, and oak leaves.
Never compost ashes or any animal products, such as meat, fish, grease, or even droppings. Ashes will slow the process considerably, and animal products will attract vermin.
When you start composting your wood shop waste, you’ll want to try to achieve a mixture of about thirty parts carbon to one part nitrogen in your compost bin. This sounds like great news if you make a lot of sawdust, but be aware that sawdust is very high in carbon (a carbon to nitrogen ratio somewhere around 250-500 to 1) and it’s usually very dry. Carbon is the easy part, so look for a lot of greens to combine it with, and try to keep it moist to the touch (but not wet). Food scraps and other green, moist plant material such as grass clippings are best at introducing nitrogen. In a pinch you can go to the home center for manure.
Add some water to keep the compost moist and to get things cooking, and stir it up (“turn” it) every so often to mix it up and let in some fresh air, and before too long you’ll notice that your pile of debris is actually heating up. This is because hundreds of little (often microscopic) organisms are munching away, turning your sawdust and banana peels into a dark, earthy, nutrient-rich compost that your plants will love.
What You’ll Need
Start with a compost bin, and put it somewhere in your back yard. Some communities and towns even sell these every once in a while at deep discounts to help promote composting (thereby reducing garbage collection and landfill burdens). You should also pick up a stainless steel container to temporarily hold kitchen scraps until you get them outside, a large garden fork to help stir (or “turn”) the pile, and of course a healthy supply of power tools to produce all the browns you’ll need to get the pile cooking. (“If you want better compost, dear, you’ll have to let me pick up that new thickness planer!”)
From the Home & Yard
Here’s where you’ll get a lot of your greens. When you’re preparing meals, open up your stainless steel container, and just dump all the unwanted, leftover plant materials you create. Do the same when you clean out the fridge – just because the lettuce is too old for you to eat, doesn’t mean it’s too old for the compost heap! You can chop up larger pieces to get things moving a bit quicker.
If you’re hooked on coffee, like me, pile on all the used coffee grounds and filters, too. Coffee grounds are a fantastic nitrogen-packed green, so when you visit your local coffee shop, ask for their used coffee grounds. Many Starbucks coffee locations even bag them up for you and place them by the door, marked “free.” If you’re not hooked on coffee, this is the perfect excuse to get hooked: Tell your significant other that buying that new espresso machine will help you save the world, then read my article on Making Perfect Mocha Syrup to get on the right track.
Now that you have some caffeine in you, run around the house gathering up dying flowers and plants, and cart that all out to the compost pile, too. And then go mow the lawn and throw the clippings in the mix as well. And if you’re lucky enough to live on the beach, grab some seaweed, too.
From the Wood Shop
Collect all your natural wood sawdust, chips and shavings and haul them out to the compost pile. (Wear a mask because the dust will go “poof” when you throw it down and stir it.) Don’t compost dust, scraps, or shavings treated lumber because they contain chemicals you don’t want your tomatoes to grow in. Interestingly, the urea formaldehyde used in MDF resins is also used as a synthetic fertilizer, but I’d still avoid using it and other sheet goods for compost as well – just in case.
When you set up shop for treated lumber and sheet goods, take all your good, natural wood waste out to the compost bin, throw it on, and give it a quick mix. Then, when you set up shop again for natural wood, take all your “bad wood” dust and debris out to the trash so you can start collecting the good stuff again.
That said, it’s important to note that some trees produce chemicals that other plants don’t like. Butternut and Black Walnut, for example, produce a chemical called juglone, which is a fungicide and antibiotic, but also tends to kill tomatoes, peppers, eggplant and some other plants. While it’s certainly not a good idea to spread fresh Black Walnut sawdust to mulch your tomato crop, it’ll be okay if it’s left to cook in a compost heap for several months. This is because juglone breaks down under the same conditions in which compost thrives and cooks. A good way to test your compost for this toxin is to plant a tomato seedling in it and see what happens.
Cooking the Compost
You know you have a good mixture of greens and browns when your compost pile is cooking. This means that it’s slightly moist and literally warm or hot – at a higher temperature than the air around it. Sometimes you’ll open up the lid and even see steam escaping when you stir it. You can test the temperature with composting thermometer, or just stick your hand in and dig around.
If your compost is not warmer than the outside air, you probably need to add some more greens or some water and give it a stir. Alternatively, if your compost pile is starting smell foul (like rotting eggs), it’s probably time to start a new project in the wood shop because you need to add more browns, dry it out a bit, and give it a good stir to aerate it.
If you actively attend to your compost, stirring it up once or twice a week, then you can get some good compost in just a couple of months. If you’re more laid back like me, just stir it up when you think of it, and then “harvest” it maybe once or twice a year. I use a large plastic composting bin, so when I harvest my compost, I open the bin up (leaving the pile of compost on the ground), move the bin over a few feet, and start shoveling the parts that aren’t cooked enough back into the bin. What’s left over is a rich, earthy compost that goes into the garden or onto the lawn.