Pot drainage: why water must run out of the holes
Roots need air as well as water. If water stays in the pot, the roots cannot breathe and they rot. Good drainage is the best defense against over-watering.
This is general care advice. Check the label of your plant. Keep toxic plants away from pets and children.
What you need
- A pot with holes
- A saucer
- A sink or tray
- Fresh potting mix (if you must repot)
Steps
- Look at the bottom of the pot. Find the holes. A pot with no hole is a risk for most plants.
- Water the plant in a sink. Water slowly until water runs out of the holes. Good drainage: water starts to run out within a few seconds to one minute.
- Wait 15 to 30 minutes. Then empty the saucer. Water in the saucer soaks back into the soil.
- If you use a cache pot (a pot with no holes), lift out the inner pot after you water. Pour away all water in the cache pot before you put the inner pot back.
- If water drains slowly or stays on top, loosen the top soil gently with a chopstick. Slow drainage often means compacted, old soil.
- If water still does not drain, repot the plant in fresh, airy mix. See the guides on aeration and repotting.
Check your plant
Answer the questions. The guide shows what to do.
Warnings
- Standing water in the saucer or cache pot can cause root rot.
- Do not put gravel at the bottom of the pot. It does not fix drainage.
- Water that runs straight through and leaves dry soil can mean the root ball is hard and dry. Water slowly in two rounds.
Questions and answers
Can I keep a plant in a pot without drainage holes?
It is risky. Keep the plant in a plastic nursery pot with holes, and set that pot inside the pretty pot. Pour out extra water each time.
Why does water drain so slowly?
The soil is often old and packed, or fine roots fill the pot. Loosen the top soil, or repot in fresh, airy mix.
Should I leave water in the saucer?
No. Empty the saucer 15 to 30 minutes after you water. Roots that stand in water can rot.