Drainage.

The downward flow of excess water out of a growing medium and through the holes of its container after watering.

What it means for your plants

Water until 10–20% runs out of the holes, then empty the saucer or cachepot within 15–30 minutes. A gravel layer at the bottom raises the perched water table rather than improving drainage; a coarser mix and a pot with holes do the work.

Put it into practice

Learn when to water houseplants, check moisture below the surface, wet the root ball evenly, and adjust your routine as growing conditions change.