Drainage is a hugely important element for growing any plants in a planter or container. If there is nowhere for excess water to go, then it can pool in the bottom of the planter and ultimately kill the plants.
Every planter must have holes in the bottom for that surplus of water to drain out from and those holes need to be kept unblocked and able to flow. The likes of broken pots, stones, or more unusual household items can be utilized in the bottom of planters, though care needs to be taken to ensure they do not affect the water getting to and out of the drainage holes.
