What are the disadvantages of sandy soil for gardening?

Less stability in the root system, as far as the plant actually being able to keep itself from toppling over. Naturally , really small plants would have no problem with this. Sandy soil also drains water and food away from the plant faster than it can be absorbed.

Answer

The main problem in sandy soil is the lack of humus content, thisdoes not allow the retention of moisture and fertiliser is liable to leach out before the plants can utilise it.