"If we take good care of the soil, the soil will take care of our plants, helping them grow strong and healthy," he said.
What began as a hobby during the movement control order (MCO) period five years ago opened Yap's eyes to the potential of food waste in gardening.
His own mini home garden, where he cultivated vegetables, fruits and herbs, thrived on compost he made entirely from the food scraps generated by his household.
Through his own do-it-yourself and trial-and-error efforts, Yap managed to produce compost within three months. His family enjoyed their homegrown produce and even shared it with neighbours, easing the household's burden during the MCO.
"After seeing how well the plants grew using food-waste compost, I began to think bigger. I wanted to start a bigger garden that could benefit the community while turning food waste into compost.
"This is because I began to realise the prices of vegetables and fruits rise when farmers are forced to buy expensive chemical fertilisers. And not many people are willing to separate their food waste and turn it into compost because the process is complicated and smelly. That's why I made it my mission to reduce food waste from ending up in landfills and instead 'save' it by turning it back into food," he said.
According to data from the Solid Waste Management and Public Cleansing Corporation (SWCorp), Malaysia generates approximately 40,000 tonnes of solid waste daily.
As of September 2025, 44.5 percent, or about 18,000 tonnes, consisted of food waste. Much of it ends up in landfills, releasing methane gas and further harming the environment.
Yap, who was a university student then, began pursuing his mission by looking for a suitable site to create a garden powered mainly by food-waste compost. He started his first urban garden in mid-2022 on a plot in Setapak here before moving to the present site in early 2023.
He also began collecting food waste from homes and restaurants in Setapak and Wangsa Maju almost daily as early as 3.30 am, riding a modified tricycle.
"Some restaurant owners generously gave me their food waste for free, but there were also those who took the opportunity to charge me," he said.
After collecting waste from restaurants and even hospitals, Yap would arrive at the garden by 7 am to produce compost before heading to his 9 am classes.
There were times he fell asleep during lectures due to exhaustion. Still, he managed to complete his four-year mechatronic engineering course successfully.
"While my friends went on holiday during semester breaks or relaxed after class, I chose to spend my time with food scraps, compost and my plants. I also took on part-time jobs to fund my garden project.
"I knew I wanted to build a career in agriculture, starting with composting food waste. To succeed, I had to make sacrifices," he said.
At first, his family did not support his career choice and his mother even thought he had lost his mind.
"My family was worried that people would avoid me because I smell bad after collecting garbage and food scraps. But over time, when they saw the results of my hard work, they began to accept and support what I was striving for," he said.
Yap's determination eventually paid off when he founded the social project Trash to TrashURE and 4Leaf Nursery in 2023.
According to Yap, making compost is not simply about dumping waste into a bin, adding it is a carefully balanced ecosystem involving microorganisms and insects.
"Composting is a natural decomposition process using organic materials such as food scraps and garden waste to produce nutrient-rich soil. This process is driven by microorganisms and natural 'workers' in the soil such as earthworms, snails and fungi," he said.
Kitchen waste like fruit peels, coffee grounds and eggshells breaks down with the help of worms and insects, while cooked food scraps such as rice, fish and meat require the help of bacteria like lactobacillus and fungi such as aspergillus and penicillium.
Yap said many people dislike the smell and wet texture of food waste, but he found an effective way to eliminate unpleasant odours.
"The secret is using dried leaves and wood chips. For every layer of food waste, separate it with a layer of dried leaves, wood or paper. This helps balance the decomposition process, eliminates odour and ensures good aeration in the compost," he explained.
He added that if someone wants to make compost at home, they should start with fruit and vegetable scraps and avoid oily leftovers, meat and bones.
With the support of the Setapak Permai Residents' Association and volunteers from a nearby People's Housing Project (PPR), Kebun Lestari Setapak Permai now receives 200 kg of food waste every day from households, restaurants and Kuala Lumpur Hospital.
Hence, Yap's present mission for the garden is simple: "Let nature play its part."
"We work with the environment by understanding every living organism around us and using them to our advantage. For example, many people see worms as pests, but they are actually microbes that play a big role in breaking down soil.
"When I first started this project, the soil (on the site) was hard and waterlogged. After adding compost, the soil became fertile and the plants grew healthily," said Yap, who sells produce from Kebun Lestari Setapak Permai to the local community, while volunteers who assist him receive vegetables for free.
Yap also encourages people not to clear patches of shrubs, grass or fallen leaves from their gardens as these act as natural ground cover. They help retain soil moisture, protect microbes from the heat and prevent erosion during heavy rain. Fallen leaves will eventually break down into organic matter that enriches the soil.
"Here, our garden (Kebun Lestari Setapak Permai) doesn't just supply vegetables, fruits and organic compost to the local community but also serves as a space to share knowledge on sustainable gardening and connecting with nature," he said.
Yap also uses organic pesticides like wood vinegar, which support pollinators such as bees and encourage natural pollination. He also sells his organic compost to the surrounding community and to corporate companies at reasonable prices, ranging from RM18 to RM300 for bulk purchases.
Yap's current mission is to raise awareness among more local communities about turning waste and food scraps into compost and starting their own urban gardens to strengthen food security.
Having already embarked on his Urban Recycling Ecosystems (UREs) initiative - community centres that turn waste into something useful - he works closely with residents to share knowledge on how to create their own organic gardens at home.
"To make URE successful, we need five elements: convenience, an educational operations team, discussions with management bodies (such as government agencies and organisations) and a market.
"If waste has no solution, it remains waste. But when combined with URE, it becomes trashURE (a valuable treasure)," said Yap, who was invited to speak at TEDx Petaling Street last year, where he shared with young audiences his journey of building a career through food waste.
"Don't be afraid to make a change. At first, people may think what we're doing is disgusting, but once we prove that something unpleasant can turn into something valuable, their perception will change.
"In my life, there is no such thing as 'disgusting'. The waste I see before me is 'gold' and a source of livelihood," he said.