Should plant pots have drainage holes at the bottom is a matter of intense debate among agriculturists and botanists across the world. While most acknowledge the importance of drainage holes, others question its efficacy, especially when compared to other alternative methods like terracotta pots and pebble layer at the bottom.
The primary argument of the "drainage holes are a must" camp is that the roots suffocate due to lack of oxygen in soil which is overly drained in water. But if that were the case, how can so many plants underwater (on the seas and ocean floors) be able to survive? Also, how come hydroponic systems work as the root is entirely submerged into the water in that case?