Conventional compost, hot compost, Bokashi bins, worm farms . . . with so many different ways to compost organic matter it can be difficult to make sure you’re getting it all right. Worm farming, also called ‘vermiculture’ or ‘vermicomposting,’ is a method of composting using worms, traditionally tiger worms in New Zealand. This compost is particularly nutrient rich as a result of the worms eating and excreting the organic matter. Here at the Sustainability Centre our worms are thriving, and if you follow these guidelines, yours will be too.
There are several key components to ensure that your worm farm will be successful. It’s important that the site for a worm farm be reasonably shady. If the worms aren’t kept in moderate temperatures, between 10 and 30 degrees, they can be in danger of dying. The worms also need a moist environment, but shouldn’t be soaked. Worms can eat their own weight in food per day, but if they are overfed the remaining food will rot, which can cause smelly odours. Smaller bits, less than 2cm, are eaten more quickly, which also helps minimize odours. You may have a bunch worms and food waste on your property, but that doesn’t mean they need to smell.
To ensure all food in the worm farm is eaten and the best compost is produced, make sure the worms are fed an appropriate diet. Worms like most fruit and vege scraps, but they won’t eat garlic, onions, or acidic foods such as lemons. They’ll eat coffee grounds and tea bags, but make sure the tea bag isn’t plastic. Crushed eggshells, dirty paper, and even hair are all safe for worm farms as well. Worms are great for turning kai into compost, but not all food waste can be disposed of in this way. They will not eat spicy foods, meat and milk products, flour products, or cooked food. Fear not though, this food can be composted in Bokashi bins and does not need to be sent to landfill. Garden scraps like grass cuttings should be left for conventional compost heaps instead of being put into a worm farm.
Food collection in the WRT kitchen ready for the worm farm!
If you keep to these guidelines, the tiger worms hanging out around your home can turn food scraps into compost full of nitrogen, phosphorous, and potassium. At the Sustainability Centre, food scraps from the Kai Conscious Cafe, as well as paper towels from the kitchen and the bathrooms, are fed to the worms. This keeps these items out of landfill, disposing of them in an environmentally friendly way, all while producing compost for future use!