I live in Banaswadi area, Bangalore. I have 20x20 ground floor area available for gardening. A few months back, I got the earlier soil excavated up to 16 inches and refilled it with a mix of red soil and cocopit (coconut husk). I planted a few flowering plants, but I do not see proper growth. I think that nutrients are missing. What kind of nutrients I should use? Any compost/manure/fertilizer that I should use? I would prefer natural remedies for the same. Please guide me for this. Thanks!
It does sound as if you are lacking organic material in your soil mix.
Here are some articles that will help you.