Plants vary widely in their water requirements and the amount of water needed depends on a number of factors: the type of plant, the stage of growth, if it is established or a recent transplant, soil type, weather and time of year. The first thing most of us do when we see our plants drooping, is to rush out and give them a drink. However, a thirsty plant and one that is suffering from overwatering both droop, wilt, and look generally unhappy. How to tell the difference? It all comes down to roots and soil.