Compost - from leftovers to black gold

I recently sat down with Roslindale resident Dan Bensonoff to learn about his easy compost set up and its many benefits.

Robert: Dan, let’s start at the beginning. What is compost? How is it different from soil or fertilizer?

Compost is a type of natural fertilizer made of organic material like leaves or food scraps broken down by bacteria and fungi. People have been composting for a very long time.

Compost looks like soil, but is much richer than soil. One important reason for that is all the microorganisms that go to work on it. One teaspoon of compost has more organisms than all the people on earth. This is also the reason compost gives off heat while being decomposed; like if many people suddenly gathered in one room, all the bacteria in the brown mix generate a noticeable combined warmth.

Once the gradual process of decomposition is done, the finished compost is a fantastic addition to your soil. It’s really light and acts as a sponge to retain water in the soil. It provides a slow, steady stream of moisture for plants and adds a lot of important nutrients that they need. That’s why gardeners have nicknamed it “Black Gold”.

It provides a slow, steady stream of moisture for plants and adds a lot of important nutrients that they need. That's why gardeners have nicknamed it "Black Gold".

Robert: I see you don’t have a big garden though, and I don’t either at home. Why do you choose to compost if you don’t have a lot of plants to care for?

To start, in this house of four adults, it’s a very easy process that takes up a tiny amount of space. If you have a few spare square feet in your yard, you have all you need. I use our finished compost for potted plants and seed starting.

If you have extra compost there’s plenty of options: give it away to neighbors, grow some plants (potted or garden), or share it with a local community garden.

I haven’t filled up my backyard bin in the past year and a half, and in that time, we’ve reduced our trash so much that I only need to put it out every other week. I’d much rather help sequester carbon in the soil than contribute to methane emissions that come from waste disposal.

Compost cheers me up too. It’s fascinating to watch the process from death to rebirth, and I interact with so many bugs and little bits of life as a result.

Robert: Walk me through your process from kitchen to bin. What does it involve?

It’s pretty simple. I throw all my food scraps except meat, fish, and oily ones into a kitchen pale and drop it into my backyard bin when it gets full. Now those scraps will compost just fine, but the downside is that they may attract rodents, so I leave them out. By using a reinforced bin, you can minimize the possibility of animals getting in.

Once the leftovers are in the bin, the two factors I pay attention to are the level of moisture and the chemical balance of nitrogen and carbon. Nitrogen comes from adding food scraps and fresh grass clippings, and you can add carbon using hay, straw, or sawdust (like I do). I’m not measuring anything when I do this, just using sight and experience.

Then, I periodically turn the mix and check the moisture level. If you get a funky smell, it probably means either the moisture or chemical mix is out of balance. Just like we need oxygen, the bacteria that are decomposing the compost pieces need oxygen to do their jobs. Without it, things get funky.

The decomposition process in the bin can take as little as a month or so and as long as year, depending on when you need it. I like to leave extra time for each batch to break down. The process is faster in the summer and goes mostly dormant in the winter. Many bins have a bottom flap with easy access to the most cultured compost ready for use.

Robert: Any advice for people who may not have done it before?

It’s one of the easiest things you can do for such a great result. You have to make it work for your life. If you have a few extra feet in your yard, that’s all you need to get started.

If you are interested in backyard composting in Boston, you can find out more on our website, including how to buy a subsidized compost bin or make your own at home.