Leaching.
Flushing accumulated soluble salts out of a growing medium by running a large volume of clean water through it and discarding the runoff.
What it means for your plants
Run 2–3 times the pot’s volume of water through the mix every 2–3 months, or whenever a white crust appears. Only leach pots that drain freely and have healthy roots, and avoid water from salt-based softeners.
IN PRACTICE
Pouring 6 litres of rainwater slowly through a 2-litre pot clears the salts that caused a peace lily’s brown tips.
Put it into practice
Brown leaf margins, dead root tips and a white crust on the mix point to soluble-salt injury. Learn how fertilizer burn happens, how to leach a pot and when to repot.
Fertilizer burn in houseplants: diagnose it, flush it, recover