How-to: urban composting with bokashi, worm farming, and more!

Recycling plant matter into plant food is half of the cycle of life. Kaitlyn Lamb describes how this can be done on any scale, in any place – even the most urban situation.

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Soil life, sequestering greenhouse gases, community connection…, composting offers an infinite number of benefits, enhancing not only the health of our soil, therefore our food, but also our mental wellbeing.

Composting can bring people together, but also the soil bacteria, mycobacterium vaccae, helps to release serotonin (the happy chemical) in our brain. As an urban dweller myself, I find it very grounding to have a compost pile at the back of my flat. When stressful days of uni arrive, I know I can turn the compost and have my hands in the soil to magically feel better.

One great thing about composting, is that no matter your living situation, there is almost a 100 percent chance that there will be a composting option for you. Bokashi. Worm farming. Composting. Sharewaste. These are the four main options of turning urban food scraps into soil.

Let’s start with bokashi.

Bokashi is fabulous for those that live in an apartment or in a house with not much outdoor space. You don’t need any grass space, as the bokashi container can sit inside your house. This process is simple, but can take a bit of trial and error to get the process to work correctly. The bokashi sprinkle (or bran), is sprinkled over the food scraps (pictured above). Within the bran are microbes which ferment the food. If you tend to have cooked dairy or meat products leftover from meals, this could be the solution for you as bokashi can process these.

It is important to note however, that once the food ‘waste’ has finished fermenting, it will need to be dug into the soil or added to a compost pile. Bokashi is a great compost activator, so community gardens may gladly accept it from you!

Next is worm farming, also known as vermicomposting.

Worm farming is super groovy, as the worms you find in worm farms are not your ordinary worm. They are tiger worms. Thus, you cannot just obtain worms from the soil, you will need to: a) get some tiger worms from others who worm farm, potentially community gardens, or b) buy worms online. Once this is sorted, you will also need a worm-farming container, which you can make yourself or buy.

Worm farming is fabulous as, like bokashi, you don’t need a lot of space, or outdoor space for that matter, as you can have worm farms inside. What you feed the worms is different from bokashi. It is better to give them fruit and vegetable scraps, with limited citrus, rather than giving them cooked or processed kai such as bread or meat. Keep this in mind when choosing which system(s) you are going to have.

My favourite method of all is the composting method.

It is my favoured because the soil we are creating has contact with the earth, so she is flourishing with vitality! There are many types of composting methods, but for the backyard, urban composter, you’ll probably stick to cold composting; slowly adding organic materials to the pile as you obtain them.

When composting, you will need outdoor space that has contact with the earth so you can build your compost pile on top of grass or dirt. Using the cold composting method, try to avoid adding processed foods, especially those with meat and dairy. This is because the pile won’t heat up enough to kill off the undesired bacteria and pathogens. If you do wish to add these, try out hot composting.

To help you decide which method to use, let’s quickly compare worm farming to composting. Within these two methods, you are going to have materials known as ‘browns’ and ‘greens’.

Brown materials aka carbon, are the drier materials that were once living, but not anymore. These include paper, wood chips, straw, and dead leaves. Green materials aka nitrogen, are fresh and smelly, which include animal manure, coffee grounds, fresh grass clippings, and food scraps.

In a worm farm you want to have about 70% of your materials greens and 30% browns. In contrast, in a cold compost, you want about 40% green materials and 60% browns.

I tend to find people on average have more food scraps, and green materials, compared to brown materials, which means worm farming is probably better suited to them.

But there is one more option.

If you don’t have time to do any of these methods but still want to help create soil aliveness, slow down climate change and foster community connection, then the app ShareWaste is for you! This app can be downloaded for free and connects those who wish to compost their food scraps with those who compost, worm farm, or bokashi already. Of course, if you don’t have a phone, you can talk within your neighbourhood and find someone who would be willing to recycle your food scraps into soil.

Kaitlyn Lamb is a university student, compost encourager, urban farmer, and Soil & Health NZ councillor.