Okay, this one is not a home project; you are going to need some professional help. But either way, this is how it's done.

The terrace is lined with a galvanised steel sheet custom-made to fit your terrace. This is to waterproof the floor and prevent leakages. The sheet slopes towards the drainage system that has to be pre-accommodated.

After that the foundations for the garden are laid i.e. the soil, fertilisers etc. Finally, the plants, bushes and even trees can be planted.

Landscaping your terrace can cost about Rs.200 to Rs.300 per sq. ft. This is excluding the plumbing charges.