Green Waste Composting in a School Setting

In a nutshell:

Schools are typically spaces with a lot of green waste: grass clippings, tree prunings, weeds, and mulch. Imagine using all this constructively to create that necessary resource - compost for the edible gardens? That's exactly what Blue Borage does, along with education on companion plants, the benefits of seaweed, cow manure and Biodynamic compost preparations. 

Read on to see an example of this process in a mainstream primary/intermediate school in West Auckland. This system works so well, that you may find you never have to purchase compost ever again! 

Step One: Labels

As with many other projects, communication is often the key to success. Making signage with the children is my preference, they almost undoubtedly enjoy the chance to paint, and their classmates are more likely to respect the signage than if it is overly formal or commercialised. 

Signs I recommend are: 

  • compost ready to use
  • compost cooking
  • compost resting
  • leave empty for next hot compost
  • grass clippings 
  • kikuyu grass drying
  • fresh weeds 
  • brown materials
  • mulch
  • chicken manure
  • cow manure
  • seaweed

I enjoy using simple shipping pallets as the walls for storage: they are untreated wood, will break down over time, can be sourced for free (or very cheaply), and are sturdy enough to contain the materials effectively. The one disadvantage is they are not rodent proof - this method of green waste composting is not well suited to food scraps for the reason that it isn't rodent proof. 

Step Two: Make a hot compost pile

When I am making hot compost at home, I make sure I have a whole day for it, or half a day and ALL the materials to hand. 

In a school setting I have done it over four lessons, and once children know what they are doing, then a class could probably do it in an hour (if all the materials were ready to go)

I don't add layers, but rather mix all the materials in a bit of a pile, then add them on top of the growing compost pile: too often I have opened up compost piles to find a few leaves that have formed a layer that stops air and moisture moving up or down. 

Adding water, weed tea, seaweed tea or cow manure slurry periodically while building the pile is important - you need the right moisture levels to heat, cook, and transform in an optimal way. 

Step Three: Monitor, measure, record, and observe

It's tempting to walk away and forget the compost once it's built, but for the sake of refining the process later, it's really useful to monitor the heating and cooking phase. In a large compost pile of one cubic metre, it's a good idea to take 10 temperature readings on a daily basis - learn which corners or which side of the pile is hot, which is cold, and see if you can work out why that might be. 

This is a fabulous task for kids to take charge of, and there are numerous applications for science and technology lessons.

Step Four: Continuous Improvement

Some ideas on how to improve your compost follow: 

  • Grow companion plants and learn what qualities they add to the soil: comfrey, clover, dandelion, borage, stinging nettle, yarrow, chamomile. 
  • Study the differing qualities of various animal manures, use horse, cow, chicken, sheep and observe the difference in the resulting compost. 
  • Take the particular qualities of the land you are on, and find ways to make use of waste materials as a resource: example here is we dried the kikuyu grass till it looked like hay, then dunked it in a clay slurry to form the final 'skin' layer of the hot compost. 
  • Get a set of Biodynamic compost preparations and add these to the finished pile. 

Making soil is such an important part of gardening, it is a process that could easily be brought into the garden to table curriculum, whether you are an Enviroschool or not. 

To book a consultation with Blue Borage, make an appointment for a conversation about your particular environment. I'd love to help you make beautiful soil. 

Book a call here.

Case Studies of school composting systems

There are two case studies of school composting inside the Blue Borage online course 'Workplace Edible Gardening', one is a really special interview with the twins Kaitlyn & Jessica Lamb, who led the implementation of composting in their high school.

Go take a look.

Ideas for innovative edible gardening solutions using biodynamic methods to make exquisite compost is what the world needs right now. To see the full range of online courses go to blueborage.teachable.com or get in touch by email at katrina@blueborage.co.nz


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