Many people who have never grown tropical vegetables have asked me about the amount of direct sunlight needed. Well, at least 6 hours a day. In fact, the more the merrier.If you're thinking of growing chye sim or bai cai indoors, you can forget about harvesting them. The seeds will germinate but without enough sunlight, the seedlings will grow up weak and spindly.
In my patio garden which is bright and warm but seriously lacking in direct sunlight, I have difficulty growing tropical vegetables. Only the rocket (which is not a tropical plant) is doing well.
On the other hand, at our office balcony where the sun is so harsh that our lantanas were quickly fried and killed in the heat, the vegetable seedlings are thriving.
Both pots of chye sim and bai cai seedlings, sowed in early May, are exposed to full sun all day.
They seem to enjoy the heat as they're growing up rapidly. They look so lush and healthy too.