Verkkoalthough one hole is enough for a planter 6 inches or smaller, three or more holes for water to escape through are necessary for larger pots. Verkkothe grail ceramic pot is designed with a drainage hole that prevents overwatering and keeps your plants healthy. The ceramic base plate is included to catch any. Verkkogravel or stones can also be at the bottom of a planter, but only to thinly cover and protect the drainage holes and not as a thick solid layer.