FIELD NOTES / EVERYDAY ECOLOGY

Water in a planted container



Sofia Marino / 2026-04-11



Water balance

Water enters a container through rain and watering. It leaves through drainage, evaporation from
the surface and transpiration through leaves.

A saucer that remains full can keep the lower roots wet for too long. Check both the surface and the
drainage holes before adding more water.


Observing rather than guessing

A dry surface does not prove that the whole root zone is dry. Compare the weight of the container
after watering with its weight several days later.

Record the date, weather and approximate amount of water. Keep the container and soil mix
unchanged while comparing observations.


Interpreting a small trial

Two containers may differ in leaf area, wind exposure or drainage. A difference in water use cannot
be assigned to one cause unless the other conditions are controlled.

Repeat measurements over several days. A single hot afternoon should not determine the watering
schedule for an entire month.


Key terms

Evaporation: Water changing from liquid to vapour at a surface.

Transpiration: Water loss from a plant, mainly through leaves.

Drainage: Water moving out through the base of a container.


Questions for review

• Why can two equally sized pots dry at different rates?

• Which observations would help distinguish poor drainage from insufficient watering?