We recently covered an approach to mixing up the best batch of soil for your raised bed garden. As with most discussions on gardening, the topic of compost came up. Compost can come from any kind of organic matter, and adding it to your soil will enrich it considerably. And, while you can go to the store to buy your compost, it’s pretty simple and a whole lot cheaper to make yourself. So, here’s how to make your own compost.
What You'll Need
- Suitable space in your yard, and possibly some structure to keep your compost in
- A shovel or rake
- Water
- Oxygen
- Brown waste (carbon)
- Green waste (nitrogen)
- Time
What Is Compost, and What Does It Do?
Basically, compost is the end result of the decomposition of organic matter. It can include lawn clippings, garden waste, kitchen scraps, leaves, straw, sawdust, and even manure (there are some caveats with some of these, which we’ll discuss later). When it reaches its prime as compost, it will look dark and crumbly and smell earthy.
Compost is likely the best amendment you can add to your soil. It makes any soil better. Compost makes nutrients more easily accessible to your plants, improves soil structure, and helps out with necessary microbial activity in the soil. It attracts earthworms, which also do their part to enrich the soil. Compost can suppress or even kill off some soil-born diseases. Finally, compost keeps organic waste out of our landfills and reduces greenhouse gasses.
Check out our guide to organic fertilizer!
How To Make Your Own Compost
Get Your Space Set Up
You’ll need some space to let your compost “percolate”. How much space you’ll need really depends on how much compost you plan on using. For instance, serious gardeners who believe there’s no such thing as too much compost will likely want to set aside a lot more space than someone who’s really just looking to keep their flower pots nourished.
A lot of people set aside a corner of the yard to set their scraps in, and others opt for tumbling bins for a (perhaps) more convenient and aesthetically pleasing approach. Some people use multiple plastic totes to work with.
We like the 3-bin approach pictured here. It lets you have a pile for use now, a pile that’s in-process, and a pile that you’re still adding to. Since a good compost takes some time to develop (anywhere from a month or two to a year), it’s good to have a few piles going at once.
It’s also worth mentioning that, if you leave one side open, you’ll have easier access to your compost when it’s time to turn it or take it away for spreading.
In any case, a good 4′ x 4′ x 4′ space seems like a good place to start for folks who have, say, a raised garden bed or two’s worth of soil to enrich.
A Very Precise and Scientific Guide On How to Make the Best Compost Pile Ever
Just kidding. Although there are some ways to tailor compost to specific needs, we like to stick to the basic, multi-purpose approach. It’s really simple.
Basically, you need oxygen, water, green organic material for its nitrogen content, brown organic material for its carbon content, time, and some agitation here and there.
You don’t need to be super precise with your ratios here, but some of everything in this list is important.
- Oxygen: Our compost pile houses the microorganisms that break down the raw materials into the rich material we want to add to our soil. And microorganisms, like many other life forms, need oxygen to survive. That’s one reason we aerate our compost: turning it over at least once a week supplies all parts of the pile with oxygen.
- Water: The last principle applies here too. But, how much should you add? Not enough and your compost will take forever to break down. Too much and your compost pile will become overburdened with bacteria that will turn it slimy and smelly. The prevailing wisdom here is that you want your compost to have the moisture level of a damp sponge.
- Brown waste: This provides your compost with carbon. “Brown” materials include dead leaves, hay or straw, small twigs, yard debris, coffee grounds and tea leaves, sawdust, shredded newspaper or cardboard, etc.
- Green waste: This provides your compost with nitrogen. It includes things like grass clippings, plant trimmings, and fruit and vegetable scraps from the kitchen.
You’ll start by layering brown and green materials, wetting periodically, until they’re piled up approximately 4′ high. Once a week, you’ll want to aerate the pile by mixing it with a shovel or rake.
You’ll also notice that the center of the compost likely will feel hot. This is normal, and actually a good sign. Some people refer to this process as the compost “cooking.” This process will even kill some unsavory weed seeds, fungus spores, and other undesirable elements that might have made it into the compost bin.
You know that the compost is done cooking when its individual ingredients resemble dark and crumbly soil that smells rich and earthy (as opposed to rotting or rancid). At this point, it is ready to add to your soil or use as topdressing.
Just Because You Can Doesn’t Mean You Should
Although the compost pile can take care of breaking down most organic materials, there are a few things you should avoid throwing into the mix.
- Be careful with manures, particularly horse manure. Horses are likely to have eaten from fields sprayed with persistent herbicide. It takes several years to break down, maintaining its potency despite running through a horse’s digestive tract. The last thing you want is to accidentally work an herbicide into all your soil. While farm animal (read: herbivore) manure can be a great addition to compost, modern farming practices dictate that you should be very sure where your manure has come from.
- You should never use pet manure for anything that will ever come into contact with something you’ll eat. There could be an argument made for using your pet’s waste in a compost pile you’ll spread across the lawn only, but maybe it’s not worth chancing.
- Don’t throw meat, bones, grease, or dairy into your compost pile. These materials can introduce potential disease pathogens to something you could use to grow edibles plants and herbs. They also smell bad and attract scavengers.
- Chemically-treated plants and grass could cause problems similar to horse manure. Some of the chemicals used in lawn care herbicides and weed killers will break down over time, some won’t. If you’ve used any products on your lawn, avoid using those clippings.
- Weeds going to seed can cause problems. You don’t want the seeds to survive the composting process only to sprout when you introduce that compost to your garden.
- Similarly, you should avoid throwing diseased plant remains into the compost. The disease might not survive the elements or the composting process, but why risk it?
Just Buy It
Even with how easy it actually is to make your own compost, some will still opt to just buy it instead. That’s ok, but there are a few things worth keeping an eye on, what to look for when buying compost.
For now, it’s enough to know that it’s easy to make your own compost with just a few simple ingredients, some space, and some time.