New insights into compost by Colette McKinnon

Harris Ivens, Plant Biologist of Grounded Business Solutions offers workshop participants new insights into compost

On a beautiful fall Saturday morning at Lakeside Community Gardens, Harris Ivens, from Grounded Business Solutions, a plant biologist and expert in the field, shared his approach to composting.

People with varying levels of gardening experience were on hand to listen, learn and begin a compost pile. As a novice gardener, I have done my best to summarize the key points below in a format familiar to many of us, and hopefully practical and covering the key points.

What is compost

Think of compost as free fertilizer! You take organic material such as kitchen scraps, garden debris, coffee grounds and leaves grass trimmings, build a pile and add a couple of magic ingredients that help beneficial bacteria, fungi, worms and other organisms to turn it into a nutrient-rich fertilizer.

Compost ingredients

  • 1 part green matter (chop up large pieces using shovel as you add). Greens include vegetable and food scraps, fresh grass clippings and yard waste, coffee grounds, tea bags and egg shells (dry & grind eggshells).
  • 5 to 10 parts brown matter (chop up using shovel as you add). Browns include dried leaves, grass, mulch or hay, cardboard rolls, sawdust, shredded newspaper, hair, fur, clean paper and wool or cotton rags.
  • Magic ingredient: a generous sprinkling of soil (< 1 part). Soil has the microbes (soil fauna) that will do the work as well as the minerals your plants need to be healthy!!! Soil also helps ensure your compost pile stores carbon rather than releases it to the atmosphere.
  • Water: Generous supply of water. You can leave the hose running as you build the pile.

How to build a compost pile

  1. Collect and store brown material to use as needed.
  2. Plan the location of your compost pile. Ideally it should be in a sheltered area, say under a tree or near a hedge, to retain moisture and so microbes can migrate over into the compost pile.
  3. There should be space to be able to turn the pile it at least once.
  4. Start the pile with a layer of sticks or woody plant stems like sunflower or corn stalks heavy-duty stems to allow continuous air-flow (oxygen is another magic composting ingredient)
  5. Begin to build your compost pile in the ratio described above
  6. Depending on the height of your pile, you can occasionally layer in additional woody material to keep oxygen flowing
  7. Ensure a good soaking of water. You should be able to pick up a handful of material from anywhere in the pile and when you squeeze it, get about one drop of water. (Water is a distribution highway for microbes in the compost).
  8. Monitor the pile: Continue to add water periodically as needed.- Conduct the “smell test”. Place a stick into the middle of your pile. If it stinks it should be turned. (Turning helps redistribute the microorganisms that are doing all the decomposing)
  9. Your compost is done when there are no more earthworms and your “smell test” come out sweet

Composting tips

  • To avoid attracting rodents make your compost pile unattractive to them by chopping up and spreading out any food that may entice them and keeping your compost pile in “good working order.” Encourage decomposition as described above.
  • To manage excessive flies, add more soil
  • To help retain moisture (the soil microbiology need moisture to do their work) cover with an old “ratty” tarp, that allows water and air flow
  • If your compost is high in carbon because of where, when and how it was built and you think it needs additional nitrogen, mix a nitrogen source like bone meal into the finished compost and then let it sit for a few days, making sure it’s well watered and covered with the “ratty tarp” mentioned above to let the soil biology go to town on them
  • To manage weeds which may remain viable in your compost, mulch after applying your compost with woodchips or straw.
Microbes hard at work

Note: If you are working with manure, weeds or other pathogens, heat will be important to creating a healthy compost. This process requires a more complex approach

And the most important tip of all

And one final tip from Harris:

“there are really no rules to composting except that it smells good and you are having fun!”

~Harris Ivens