Why Coffee Filters Beat Rocks for Pot Drainage

Q: What about using coffee filters over drain holes instead of rocks or pottery shards?

Coffee filters work well—soil won't wash out. Never add a rock layer at the bottom. It reduces soil volume for roots and creates a perched water table that keeps roots waterlogged.

Physics explanation: Water drains until soil absorption balances gravity. With rocks, the saturated zone sits higher—closer to roots—increasing rot risk. Rocks in pots = rocks in head!