Horticultural Composting – Putting Our Waste to Good Use

Mar 2022


Every year, the CAG Horticulture team works to beautify Changi Airport by maintaining our garden spaces and filling the airport with greenery specially grown in our airport nursery. In an effort to close the waste loop, the team has been actively diverting waste from our nursery and gardens to be used as compost.

An example of garden waste that we recycle are the withered stems of sunflowers. Instead of sending them to the incinerator, they are given a second life as compost. Sunflowers are especially suitable due to their high nutrient content and relatively short rate of composting.

Over the next few years, we plan to expand our recycling efforts to include more horticultural waste from our gardens as well as the trees and plants along Airport Boulevard.




Sunflower stalks are shredded manually with a woodchipper to enable optimal mixing and aeration. This creates a greater surface area to break down the organic matter, speeding up the decomposition process.



Shredded waste is piled up and left in the sun for one to two weeks before soil and an eco-friendly sodium bicarbonate treatment mixture are added to eliminate pests and sanitise the waste. The heap is then ploughed and left untouched for the decomposition process to occur. 



New compost is ready for use after two to three months. The compost provides enriching nutrients to support plant growth. This organic compost is not only more sustainable, but also safer than man-made chemical fertilisers that may leach and cause harm to both the environment and nursery workers. Our reduced dependence on chemical fertilisers has also resulted in cost savings.