Peace lilies will be healthier and have greener leaves if you do five-minute job
Peace lilies rank among the most beloved houseplants thanks to their stunning blooms, though they can be surprisingly demanding and moody even when you’re giving them exactly what they need. While owners want their peace lily plants to look stunning all the time, yellowing is sometimes normal, as it can signal ageing. This is mostly the case when only one leaf yellows at a time, the pot is not waterlogged, and the yellowing occurs slowly over weeks, not days.

TL;DR
- Yellowing leaves on peace lilies can be normal aging if only one leaf yellows slowly over weeks.
- Multiple yellowing leaves usually signal overwatering, leading to root suffocation and rot.
- Remove yellow leaves by cutting their stems near the crown.
- Stop watering until the top 50% of the potting mix dries out.
- Water thoroughly only when the soil is dry, and ensure proper drainage.