The supertrees are lit up when the sun has set and the night comes in. If you happen to have a lot of time in your hands, do not go home yet. There is a light performance (by the supertrees) called Garden Rhapsody - "The Trees of Life" at two timings, 7.45pm and 8.45pm. 

The night gets darker but you can still walk on the skyway until the 9ish. Since I have climbed up the skyway earlier, I decided to wait for the performance under the lit up tree. 

Garden Rhapsody is basically a lighting play with the nice music as a background. It is a very beautiful performance and it is quite fun to watch. And it's free. =)

There is a restaurant at the biggest supertree so you can also watch the performance while having your dinner. Of course, you need to pay a fair bit of money for the dinner. =P