Here is a way you can make a hanging garden in case if you don't have any patio or roof space, but you have somewhere to hang things.

This is an example of a compost garden, where you change out the composted dirt every year and place compost materials down first and then just a inch or two of good soil on top and you plant in the top layer of soil while the underlayer of compost decomposes throughout  the year. creating a fertile soil.

Here we have a wick bed and in the next picture you will seed a close up of the carpet used as a wick. Basicly you take an old carpet or blanket to act as a wick and lay it down on your roof the cover it with an inch or two of soil or composed material and plant in that. You always want to becareful to mulch these roof top gardens to help hold in the moisture. 

Here you see  the carpet underneath then the dirt and a mulch on top.

Finally so that you don't have to continually water these shallow beds you can see the 5-gallon buckets in a couple of pictures, which are used to water. You drill a small hole in the lid and fill it with water and fertilizer and then invert the bucket on to you carpet and the carpet will wick the water throughout the entire bed. You only need to fill the buckets 1 or 2 a day and have one or 2 buckets per bed, depending on the size and the weather, then your bucket waters for you while you are accomplishing other tasks of the day.