Compost: Mysteries Solved

Ah, compost! So few words in the gardener’s vocabulary can evoke both joy and fear simultaneously. I think we have all been told that compost is the gardener’s best friend, but little information exists on how to make it, or what information is available seems overly complex (e.g., specific ratios of carbon to nitrogen, strict rules of what can or cannot be included, etc.). In this blog, I hope to demystify the composting process, offer suggestions for everyone with small or large gardens, and inspire you to get your hands dirty!

What is compost?

Simply put, compost the leftover material from the decomposition of organic matter (e.g., our plants). It is nutrient dense (typically containing an excellent balance of key elements necessary to help plants thrive) and teaming with an enormous network of bacteria, fungi, and microscopic creatures, all ready and willing to do their magic in the garden. While it is perfectly acceptable to buy compost in bags at your local big box store, I prefer to make my own. I find that potting up plants in home-made compost accelerates the rooting and establishment process, likely due to my plants forming symbiotic relationships with my local microorganisms early on (e.g., many plants and fungi exchange nutrients in a mutually beneficial way; I typically add store bought mycorrhizal fungi to the planting hole of woody shrubs and trees).

How do I make it?

Since we are merely harnessing the power of a process that already takes place in nature (think of leaves breaking down in the forest), there are many ways to create excellent compost. First, I cannot stress enough how important it is to practice organic gardening. The microscopic life within the compost is the life blood of the entire process. Synthetic chemicals, such as fertilizer and pesticides, will leave you with a rotten pile of stinking goo. Compost should not smell malodorous. It actually has a somewhat sweet smell to it, similar to cooked grains or corn.

• Pile it up! Perhaps the simplest method of all simply involves finding a place tucked away in the garden to make a large pile of kitchen scraps, leaves, yard clippings, small twigs/sticks, etc. Although this is the simplest method, it is also the longest. It may take a year or two for you to see usable results, but if you do this consistently every year, you should have a continuous supply. This method is preferrable to individuals that burn their leaves/yard waste, which releases large amounts of carbon into the atmosphere. As good stewards of our gardens and the earth, we want to lock as much carbon in the ground as possible.
• Worms! That’s right, you can harness the power of the gardener’s greatest ally, the humble worm. I have used this method with great success, particularly when we were living in apartments or house rentals where I did not have the acreage I have today. This method does involve some equipment. You will need a bin system, like the one here. Simply fresh kitchen scraps (use only raw ingredients, which haven’t been seasoned or salted) to the top bin and wait for them to break the material down. Then, your place a new bin on top and repeat the process. In a few weeks, the bottom bin is ready to go into the garden. The other benefit of this system, is you get worm tea (a valve on the bottom allows you to collect the liquid and use it in your plant watering). Special note: do not try to use earthworms from the garden in these bins. There are countless variety of worms and each species is equipped for special conditions. The type of worm we want in this system are called “red wigglers.” You should see them under related products when you click the link above.
• Outdoor bins! I am personally impatient and did not want to wait on the pile it up method and the worm bins worked fine on a small scale. However, when I finally got my hands on a piece of land, I knew I was going to have to scale up. The solution involved creating outdoor bins from scrap lumber. While the specific dimensions of the bins doesn’t matter, it will note that 5 X 5 X 5 is about as small as I would make mine. We want the material to heat up to a degree capable of killing any weed seed or pathogens present in the soil mix. This heat is largely microbial and the larger you make the pile, the hotter it will get (keep this in mind that when farmers bail hay that is too green and place it in large barns, they have been known to catch fire, but this is highly unlikely in our scenario. It will get hot enough to burn your hand, so be careful!). I started by sinking four 4 X 4 posts in the ground and connecting them with available wood slats (photos below). I created 4 bins next to each other. I first pile all my fresh material in the first bin until it is full. Once filled, I take a fork and throw it into the second bin and fresh material then goes in the first bin again. Once again filled, the second bin goes in the third, the first goes in the second, and the first gets fresh material again. In this way, I am cycling the material down the line and aerating. In high summer, this process can take as little as a few months. Winter months slow the composting process down. I keep an eye on the process with a compost thermometer, seen here. This provides the ideal growing temperature for our microscopic friends. If it gets too cold, I simply churn the pile or add more raw green material. If it gets too hot, opening the pile with a fork can help, you can add some water, or add more brown material (e.g., dried leaves and twigs).

What can I put in?

You will read a great deal about people getting bent out of shape over what to include and what not to include in the compost pile. I say, if it is causing you anxiety and is overly complicated, you aren’t gardening right. The basics include, anything can go in as long as it is natural, organic, and not salted (we are not trying to salt the earth the way the Romans did to thwart their enemies). Anything cut from the garden, any fruits of vegetables from your kitchen table, coffee grounds, grass clippings, fallen leaves, etc. You will also read tons of rules about the proportion of “green” to “brown” material. This is referencing raw green material (e.g., grass) and dead brown material (e.g., Fall leaves, twigs, etc.). There are no hard and fast rules here. I aim for a nice mixture of both, but don’t stress if you get more of one than the other. The thermometer will tell you if you need to change your mix. Furthermore, the worst case scenario involves you putting in far too much green material and ending up with sludge (yes, I’ve done this), but even this can be salvaged by adding in brown material and mixing it well. Mother nature knows what she’s doing! We are just helping her along. The really hard rule of thumb you need to follow: Do not include any material that came from an animal. Animal products (e.g., meat, cheese, milk, bones, pet waste, etc.) has a tendency to attract vermin and have the potential to spread pathogens. While these bins do get hot, we cannot be certain they kill deadly virus/bacteria, so best not to include these materials.

That’s it! You are now ready to get composting! Get your hands in the dirt and Give it a Grow!

Notice on the back (the business side), I have created removable slats (a piece of wood forms a channel in which the board can slide up and down). In this way, I can slowly add or remove them as each bin is filled or emptied. This also allowed me to walk inside each bin and clean them. Keep in mind that I used wood because I had it readily and cheaply available, but this could also be made from metal (e.g., using tin).