Yellow Crusty Soil in Indoor Pots: Salt Buildup Diagnosis and Leaching Fix

That Yellow Crust Is Fertilizer Salt—Your Plants Are Being Burned

Yellow, crusty soil surface = dissolved salts (from fertilizer and tap water) accumulating as water evaporates. This dehydrates roots and blocks water uptake.

Immediate Fix: Leach the Pots

1. Take plants to sink/shower
2. Run lukewarm water through soil until 3x pot volume drains out
3. Let drain completely (5-10 minutes)
4. Return to saucers—EMPTY saucers after

Correct Watering Going Forward

• Water THOROUGHLY until 20-30% of applied water drains out
• Do this IN SINK, not in saucer
• Wait until top 1 inch (finger to first knuckle) is DRY before watering again
• Never let pots sit in drainage water

Prevention

• Use rainwater or filtered water if tap is high-mineral
• Fertilize at ½ strength, less frequently
• Repot annually in fresh mix
• Monthly leaching for heavy feeders

The "finger test" prevents both over- and under-watering. Your plants will recover once roots can breathe and drink again.