One of the best ways to help your terrace garden grow organically without too much dependence of chemical fertilizers is through composting. Compost is decayed organic material used a fertilizer for growing plants.
Terrace/Urban farming breaks all the myths of space requirement for growing Fruits, Vegetables at any available space! Yes, you heard it right! With required amount of Sunlight and materials with a little keen interest, Fruits, Vegetables or even leafy vegetables can be grown on any building today.