Comcrop – Urban Farming in Singapore

I’m interested in the future of food. By 2050, 80% of people are expected to live in an urban environment. I want to understand how we can produce food for this growing urban population.

On a recent trip to Southeast Asia, I spent some time with friends in Singapore and took the opportunity to arrange a visit to Comcrop. The Mission and Vision of Comcrop fit well with the kind of urban farming organisation I want to learn more about.

“We aim to build a sustainable business by connecting communities to healthy, locally produced food; taking care of our planet; and by making farming fun again.”

“We believe urban agriculture is the key to a sustainable city. Our vision is to create resilient, local ecosystems that produce fresh, flavorful food in cities to build stronger communities.”

I wanted to understand the challenges of doing urban farming on a rooftop location in Singapore. I went on a tour of Comcrop with Darren Tan, the Sales and Outreach Manager. The first thing to say is that the visit was at 2pm and the heat on the roof was intense! How and what can you grow on a roof under such conditions?

Hydroponics vs an aquaponic system?

The answer to the question of how you can grow in these conditions is to use vertical hydroponics. Hydroponics is a system where water is mixed with nutrients. No soil is involved. This nutrient-rich solution is then pumped around the towers and feeds the roots of the plants. The roots absorb the nutrient-rich solution and grow. At Comcrop, solar energy is used to power the pumps and the system recycles between 70-90% of the water used for cultivation. There are information boards explaining the process and why this is a sustainable approach.

Comcrop had tried aquaponics. Aquaponics is a combination of aquaculture (farming fish) and hydroponics (growing plants in water with added nutrients instead of soil). In aquaponics, the nutrients in the fish poo feed the plants. However, it was decided to switch to hydroponics. There were two main reasons for this. The first reason was that the nutrients from the fish waste contained too many nitrates for the plants that were growing so they still needed to supplement the water. Plants need the right balance and mix of nitrogen, phosphorus and potassium to grow well. If these three elements are present in the wrong proportions, it causes growth problems for the plants. The second reason for switching to hydroponics was that the fish weren’t growing as fast as the plants’ nutrient requirements.

What does Comcrop Grow?

The main crops that were currently being cultivated in the vertical towers included sweet basil, peppermint, a small amount of spearmint and wasabi greens.

We tried the basil, peppermint and spearmint which all had an intense flavour. I’d wondered if hydroponics would affect the taste of the plants: It doesn’t. The basil can cycle through a couple of times before it needs to be replanted.

They also grow lettuce. Up to 500 plants spend two weeks in the sowing stage and then take another 4 weeks to form a full head of lettuce. The lettuce is grown in the top two rows of the hydroponic system.


Darren explained that the plants need a lot of time to acclimatise on the roof. They test new plants firstly because of the heat and secondly to see if they like being grown hydroponically! It’s 2 to 3 degrees warmer on the roof than on the ground. Also, a roof isn’t a controlled environment so pests are a problem and need to be monitored. Tomatoes, for example, are no longer grown because they’ve been attacked by tomato blight.

Plants currently grown in various pots on the roof include pandan and lemongrass, ochre, rosemary, wood sorrel, butterfly pea and chillies. The key to success is to consider the needs of each plant. For rosemary and ochre, for example, clay pellets are added to the pots. These pellets help the roots of the plants gain stability and develop vigorous plants. Rosemary is a herb that would not grow hydroponically because it doesn’t like its root system to be damp. For potted plants, a drip irrigation system is used to ensure efficient use of water resources.

Fascinating Fact: The blue flowers from the butterfly pea can be used to make tea, colour desserts and create blue rice. This blue is used for blue litmus paper, so if you drop lemon juice into butterfly pea tea, the tea will turn from blue to red due to the acid in the lemon juice.

Community Engagement

Comcrop has paid staff to grow and sell its products. They sell to an online retailer and to local bars and restaurants. This creates a sustainable business. Because the business side of the company is secure, Comcrop can also offer volunteering opportunities through community engagement programmes.

As a volunteer involved in some community projects back home, I was interested to learn how Comcrop engages with the wider community in Singapore. Darren explained to me how everyone from the community can come and make a meaningful contribution to the cultivation and harvest. Comcrop also works with MIND (Movement for the Intellectually Disabled of Singapore), training people on how to germinate plants.

Comcrop also works with schools and it was encouraging to hear that the focus is on teaching students about the cultivation process as a first step. I think this is the way to really connect people with food and plants. Once someone knows what cultivation is, the focus can be on the different ways of growing food.

I would like to thank Darren for his time and willingness to answer questions. Comcrop offers private tours, like ours, for a small fee or offers a free tour on the first Saturday of the month. And look out for news of how Comcrop plans to expand its operations.

Free Farm Tours every first Saturday of the Month


The way we grow food for people in urban areas will evolve and expand in the coming years. Although it’s not clear which combination of farming techniques will be most efficient, urban farms like Comcrop are pioneering the application and testing of these different models in a tropical climate.

Singapore currently imports most of its food. Therefore, urban farms that use space-saving techniques such as vertical farming can make an important contribution to food production in the future.

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