在林世昌的努力下，都市人無需長途跋涉到郊外去開田，在天台上就能享受到親手種菜的無窮樂趣。
在香港土生土長的林世昌並非農業專科出身，本職是廣告導演。2005年開設「環保媽媽」，專賣回收二手嬰兒用品。由於生意欠佳，他被逼向工業大廈租天台樓面作為辦公室。林世昌和妻子很早之前就成為假日農夫，在新界一片100平方呎土地種蘿蔔、菠菜、青瓜及其他時令蔬菜。天台上的辦公室給了他們一個主意——大廈天台有很多戶外空間，陽光充足，很適宜種菜。幾年後，環保媽媽因租金及成本過高而結束營業，但林世昌卻發現在都市天台種菜的潛在商機。
經過兩年半的測試後，林世昌發現德國及荷蘭的混合土壤最適合天台種植箱的蔬菜生長。「香港天氣潮濕多雨，泥土的排水能力非常重要。」他解釋說。
林世昌意識到都市農莊模式並不適用於香港的所有大廈天台。他經過慎重考慮才選擇了目前兩個地點。兩座建築都是工業大廈，陽光充足，又無工業污染。「由於多數工廠已遷往內地，這兩座工業大廈已改為辦公室用途，」林世昌說。「大廈必須夠高，鄰近不能有摩天大樓遮擋，才能確保空氣流通及空氣質素好。地點亦要方便。」今年夏天都市農莊的兩個天台菜園，客人都絡繹不絕。林世昌的農夫們都非常投入於栽種青瓜、南瓜及其他中國蔬菜。
「當農夫必須不斷學習，」林世昌分享道。「有時很簡單，只須將種子埋入土裡，不必任何照顧，有時卻非常講究，需要悉心呵護。愛上種菜的人，就會像海綿一樣，不斷從親戚、朋友、互聯網或書籍中汲取相關知識。」林世昌本身也是從大量書本及上網搜集資訊，並從無數次失敗中吸取經驗。分享經驗尤其重要，林世昌因此決定為都市農莊設立臉書網頁，與客人分享照片、解答疑問及提供小貼士。「許多客人都貼上他們手捧著蔬菜的開心照片。」林世昌笑著說。無數開心笑臉正是他努力的動力。雖然都市農莊可以為林世昌夫婦帶來極為可觀的收入，但金錢並不是他們的主要推動力。導演工作已足夠滿足他們的物質需求，種菜才是林世昌的心所嚮往。
每逢周末，許多家庭都會一起來照顧他們的農作物。林世昌承認客人所種的菜其實不足夠供一家人食用。「要種一人份的蔬菜，需要至少400平方呎土地。」他說。但林世昌留意到種菜改變了客人對食物的態度。「他們第一次品嚐自己種的菜之後，不再認為有機蔬菜昂貴。現在他們會選擇更有益健康的食品。」除此之外，林世昌發現客人對彼此的態度也改變了。「他們會互相分享收穫。如果一位客人有兩條青瓜，他會用一條青瓜與人交換菠菜。」原本冷漠的都市人成為都市農夫後，變得更熱情、善良和慷慨。
當被問到都市農莊的未來五年計劃，林世昌表示不急於擴充發展。他會繼續謹慎物色好地點，培養更多新手農夫，將種菜樂趣傳揚出去，並計劃繼續發展有機耕種。更重要的是，他希望見到愈來愈多的都市農夫，努力實現都市綠色生活。

Lam has no degree in agriculture. Born and raised in Hong Kong, he is known as a commercial TV director. Lam and his wife have long been holiday farmers, with a small 100 sq ft field in the New Territories to grow carrots, spinach, cucumbers and other seasonal vegetables. But in 2005 he started a company called Eco Mama, selling second-hand baby gear like strollers and cribs. Because his business was not doing well, he was forced to rent a rooftop office. After a few years, Eco Mama’s high overhead costs for rental and manpower forced them to close the business.
But Lam saw the potential for urban farming at rooftops, and a business opportunity: there was plenty of outdoor space, and sunlight to grow vegetables. After two and a half years of testing, he has found the perfect blend of soil from Germany and the Netherlands, ideal for growing vegetables in the rooftop planters. “Hong Kong has humid conditions with a lot of rain, so it is important to consider water drainage in the soil,” he explains.
Lam also realised that not all rooftops in Hong Kong are suitable for farming. It was with careful consideration that he selected his two current locations. Both are industrial buildings with excellent sunlight and no pollution. “As most factories have moved to China, these buildings are now office spaces with no industrial pollution,” the urban farmer explains. “It has to be high enough, with no skyscrapers next to it so that there is good air flow, good air quality, and must have easy access to our clients.” This summer, there is much activity in his two rooftop farms: his eager fellow gardeners are growing cucumbers, pumpkins and Chinese vegetables.
“Being a farmer means an endless education,” says Lam. “Farming can be as simple as putting the seed into the ground, then leaving it unattended, or it can be a PhD degree. Once you click into that interest, you absorb [knowledge] like a sponge — from friends and relatives, from the internet and books.” Lam quickly learnt that farming involves a lot of trial and error, so sharing information is essential. He set up a City Farm Facebook page with numerous photos of his students smiling and posing with their harvest.
At weekends families come to visit and work together on their planters. Lam is quick to admit that the vegetables grown by his clients are not even enough for their own household consumption: “You would need at least 400 sq ft to provide for one person’s consumption,” he says. Yet, something magical is happening to these urban dwellers.
“Once people grow their own vegetables, their attitude towards food changes,” says Lam. “When they eat what they grow, the first time they try it, they no longer find organic vegetables expensive. They also make healthier choices.” As if that’s not rewarding enough, he’s also witnessed a shift in how they relate with each other. “They share their harvest. When one has two cucumbers, he gives one away in exchange for some spinach.” Once detached individuals motivated by self-interest, these city dwellers are becoming a warm, kind and generous community of urban farmers.
When asked how he sees City Farm growing in the next five years, Lam doesn’t venture a response. He simply says he will continue to select good locations and teach more neophyte farmers. Though the business has huge potential to generate income for him and his wife in the future, money is not the main motivation. His work as a TV director provides for their material needs, but his heart lies with farming.
More importantly, his true desire is to nurture city farmers sharing his passion for a greener urban lifestyle.