Composting is a fantastic way to use leaves that fall from trees and add rich nutrition to your gardens. Leaves are a key ingredient in compost as they provide carbon and other nutrients o your compost. Some tree leaves contain twice as much mineral content as manure. Leaves can also be high in calcium, magnesium, nitrogen and phosphorus and other trace elements.
Leaf compost is great at activating soil and increasing soil fertility. By using leaves rather than placing them in your bin, you are reducing the production of harmful methane and carbon dioxide in landfill.
What is leaf compost?
Leaf compost is the product of brown and green organics that break down to create a nutrient-rich soil-like material which can improve soil quality in gardens. Brown organic material includes leaves, sticks, bark, paper and cardboard. Green organic material includes grass clippings, green plant prunings and food scraps. Mixing both brown and green organics in the ideal ratio is crucial to the success of leaf compost. Typically, a mix of 75% brown with 25% green will yield the best results.
How do you make leaf compost?
Firstly, you need a place to make leaf compost. There are many store-bought composting solutions out there, but if you are handy, you can make an inexpensive leaf composter using only a couple of items from a hardware store. You will ideally want to place your leaf composter on bare ground. This will entice worms and other organisms up and into your waste pile which will accelerate the breakdown into garden compost.
Here is a simple way to make leaf compost:
- Start with some sticks and twigs as your base layer. This will help aerate the pile and help the worms and other organisms break down the organic matter.
- Add a 30cm layer of leaves. Using a small garden spade, make a “bowl” in the middle of the leaf pile.
- Fill the bowl with green matter, such as kitchen scraps and lawn clippings.
- Cover the green matter with a 10cm layer of leaves.
- Add water to make the pile moist, but not soaking wet.
- Leave the pile to start the process of breaking down into leaf compost.
- Every 1-2 weeks aerate the pile using a garden folk or a compost crank.
- Every time you want to add greens to your bin, repeat the same process – add leaves, make a bowl, add greens, cover with a layer of leaves and then water it in.
Your nose can guide you to what your leaf compost needs. If the pile smells sour, you need to add more brown matter such as leaves or cardboard. If there is no smell you need to add water.
The benefits of composting leaves
There are many key benefits to composting leaves in your garden. Don’t let this precious resource go to landfill or into our waterways!
Benefit #1. A low-cost way to add nutrients to your garden
Both green matter and brown matter are low or no cost by-products which can be added to your leaf compost. Once broken down this provides nutrient dense soil which can be used in numerous ways throughout your garden.
Benefit #2. It can improve pH in your soil
Leaf compost is a terrific way to improve the quality of your soil particularly if your soil is unbalanced. Leaf compost that is well decomposed helps lower the pH of your garden soil over time.
Benefit #3. Redirects organic waste from landfill
By diverting organic waste away from your regular bin you are reducing the amount of greenhouse gases that those organics create while decomposing in landfill. Approximately 50% of waste that Australians put in their mixed waste garbage bin could be put to better use in the garden as compost to improve soil quality.
Benefit #4. Helps gardens retain water
Leaf compost reduces your gardens’ need for water by increasing the amount of water that can be held in the soil. By increasing the organic matter in your garden beds by just 5% you can quadruple the water holding capacity of your soil.
Benefit #5 Reduces the need for chemical fertilisers and pesticides
Leaf compost helps suppress plant diseases and pests by staving off harmful bacteria and fungi that chemical fungicides combat. Leaf compost is high in organic matter which reduces the need for harmful chemical fertilisers helping you save money.
Benefit #6 Prevents blue green algal blooms in waterways
By reducing the number of leaves that run off into drains we are helping to prevent toxic blue green algal blooms from occurring in our waterways. Leaf run off contains high levels of phosphorus which is a key ingredient that feeds blue green algae.
What is The Leaf Collective?
The Leaf Collective is a community-government-university partnership of people working together to keep leaves out of drains. Led by Griffith University and funded by the ACT Government, interested Canberrans have helped come up with lots of ways to make it easier to gather and use or remove the leaf litter falling near our stormwater drains.
In late 2020 the ACT Government invited proposals for a community-based social marketing approach to the problem of leaf litter polluting Canberra’s waterways. Community-based social marketing puts community wishes and needs at the centre, and then measures effectiveness through small pilot campaigns before scaling up. Social Marketing @ Griffith were the ideal fit for the job, with their “Co-create, Build, Engage” (CBE™) process. The project team applied CBE™, working with people in Canberra to understand what they’d like to see. Read more about that work here.
The Leaf Collective was the result. In autumn 2021 a range of discount offerings, leaf pick up services, an adopt-a-drain project, a citizen science app and other initiatives were tested by the project team. In just 6 weeks this pilot program got people living in Canberra involved. The evaluation study identified that the pilot helped to reduce the amount of leaves entering ACT waterways. People living in the ACT joined the collective diverting 200,000 litres of leaves out of stormwater drains.
Our work continues and this summer we are running a further pilot based on research completed late in 2021. You can explore program elements realised after co-creation by exploring our project website. You can also follow us on Facebook to watch how our work continues to unfold.
The Leaf Collective was co-created with ACT residents and experts working on water quality, waste removal, composting and much more.