Microgardens are cost-effective and represent an option for, but not only for, a healthy food self-sufficiency and for a long-term occupation in slum areas of the cities.
The idea is simple: an empty bag is proportionately stuffed with soil and humus and perforated at some points. Then plant seeds or cuttings are put in and watered. Thus, vegetables can be reaped even in very confined spaces.
The concept of microgardens is more and more accepted also in Africa.
In this way, schools in Africa provide their children with self-grown food while urban development concepts, too, integrate the idea of vertical gardens.
Read and see more:
Garden in an bag. https://www.youtube.com/watch?v=x4e48SdJT4M and