Claire Mummery: How to handle food waste after a natural disaster

Reset's gardening expert Claire Mummery explores options for handling food waste. Photo / Getty

Gardening expert Claire Mummery breaks down simple ways to dispose of food waste.

One of the greatest outcomes of Cyclone Gabrielle has been the heart-warming presence of community spirit, unity and boundless generosity across Aotearoa.

Following unexpected catastrophes, there are always silver linings to bring us hope, including the opportunity to learn and grow as we move forward together. Once the immediate damage has been controlled, it is vital that we each reflect upon how we can better prepare in future.

Among the numerous challenges presented by last month’s cyclone was that a host of essential services became unavailable for affected communities for long periods, including waste collection.

In preparing for a natural disaster this scenario is often overlooked, but following long power outages, large volumes of food waste rapidly become a high priority. If you have no way to process your own waste at home, your only options are to fill your already-overflowing landfill bin until collections resume or to bury it.

My philosophy is that we can all stand to become more self-reliant - and processing waste is no different. Composting at home can most certainly be considered a necessity in this journey to self-reliance - and it offers incredible benefits for growing a food garden too.

Let’s explore your options.

Bokashi composting

Bokashi is a clean and fuss-free way to process food waste, as it is a closed (anaerobic) fermentation method, using beneficial microbes to quickly break down food without odour. These microbes (effective microorganisms or EM) are either in the form of a bran or a liquid and will not only process food without harming the planet, but they will also actively help to rebuild your soil and enhance future plant growth.

The beauty of using bokashi is that all solid food waste and paper can be processed within one system, with the exception of fish bones. The solid matter can then be added to your raised bed or containers as a layer of nitrogen, in between carbon layers, to feed your growing plants.

There are only three basic guidelines to follow:

1. Always close the lid firmly (no air).

2. Never add liquid waste.

3. Strain the resulting “bokashi” juice every three to five days from the bottom of the compost bin.

Two fantastic uses for this bokashi juice - the by-product of fermentation - are:

1. As a plant elixir to treat pests, disease and stress (dilution 10ml to 10L of water).

2. To help clean your home, as the juice is packed with good bacteria that will neutralise odours in your shower, drain, kitchen sink or toilet.

Worm farms

Worm farming is another great way of processing your food waste and it’s perfect for small families. You can add most foods in moderation (with the exception of sharp bones/shells) as well as ripped/shredded paper. The key is to chop all waste into small pieces before adding, as this speeds up the process rate.

A properly-functioning worm farm can process up to two kilogrammes of food waste a day. You can test this out by weighing your food waste before feeding it to the worms - if it disappears in 24 hours, add an extra 250g each day until there is food left when you check it after 24 hours.

Once you know the amount of food your worms can process in a day, versus the capacity of food waste that your household produces, then you will know if you have enough composting capacity in a natural disaster.

The by-products of worm farming also offer a range of benefits to your food garden, including vermicast and worm tea that both help to feed and support stressed plants.

The Black Bin composting system

I prefer to use the Black Bin composting systems for my green and brown waste, or for processing my bokashi with added carbon. Therefore, this system is always my last resort for processing my food waste, as it is aerobic (giving a chance for bad odours to develop) and there are plenty of spots for rats and mice to make a nice home.

But, in the event of a disaster, these systems would be fine to use, as long as you follow the correct “process” for composting - this means applying at least 60 per cent carbon material. On either side of your food waste on every layer, you must add a good layer of ripped-up paper, cardboard, cereal boxes, dried leaves, dried grass or newspaper.

By layering your food waste in between these carbon sources, it will enable the compost to heat up enough to effectively break down. Otherwise, layering food waste on top of more food waste all the time will produce a sludgy, smelly mess that cannot break down.

I invite you to consider which system would work best for your home and take action now so that you are ready when you need to be. Personally, I like to have all of these compost systems running in my home, as their natural by-products offer home-made fertiliser for the garden in the perfect renewable food cycle: Prepare your food - eat your food - compost food waste - fertilise and build soil - grow more food.

Honestly, what more could you ask for? Using the absolute total value of the food you paid for, and being prepared to support yourself in the event of any disaster.

Arohanui Aotearoa.

For more gardening advice, visit growinspired.co.nz and discover Claire Mummery’s online gardening course at www.growinspiredacademy.com