Diseases and pests

Root bound

What it looks like

Roots poke out of the drainage hole or circle the surface. Water runs straight through. The plant dries out much faster than before and has stopped growing.

Why it happened

The plant has outgrown its pot. So little substrate is left that it can hold neither water nor nutrients.

What to do

1. Repot into a pot 2–4 cm larger in diameter. No larger — an oversized pot invites rot. 2. Gently tease apart or score the circling roots at the base. 3. Use fresh substrate and shake off the old. 4. Water thoroughly after repotting and skip fertiliser for a week. 5. Repot in spring, not in winter.

How to prevent it

Check the bottom of the pot once a year. Most houseplants want repotting every 1–2 years.