Why Your Peace Lily Is Drooping

The plant that tells you loudly

A peace lily wilts more dramatically than almost any common houseplant. Leaves collapse over the side of the pot within hours and recover within hours of watering, which trains people to use the droop as a watering schedule.

That works until the day it does not — and the day it does not is the one that matters.

Two causes, opposite treatments

Iowa State Extension lists both under-watering and over-watering as causes of wilting. Under-watering comes from insufficient frequency, inadequate saturation, poor absorption or small porous containers. Over-watering comes from excessive frequency, lack of drainage, waterlogged saucers, compacted soil or oversized containers.

The plant looks the same either way. Watering an already-waterlogged peace lily is the most common way people kill one.

So check the mix before you water. Push a finger in to the second knuckle.

• Dry, pot feels light — thirsty. Water thoroughly until it runs from the drainage hole, and it will recover within a few hours.
• Wet, days after watering — the opposite problem. Do not water. Slide the plant out and look at the roots.

When it does not spring back

A peace lily that stays collapsed after a thorough watering has a root problem. Healthy roots are firm and pale; rotted roots are brown, soft, and strip when pulled.

At that point you are dealing with root rot rather than thirst, and the fix is to trim the dead roots, repot into fresh mix, and water sparingly until new growth appears.

Stop using the droop as a schedule

Letting a peace lily wilt repeatedly before watering is common advice and it is not good for the plant. Each wilt is a genuine water stress event, and the visible cost over time is browning leaf tips and edges.

Water when the top inch of mix is dry rather than waiting for the collapse.

The other causes worth ruling out

Soluble salts. Iowa State lists salt accumulation from excess fertiliser among the causes of leaf damage; symptoms include reduced growth, brown tips and wilting. If you feed regularly and never flush the pot, water thoroughly until it drains freely a few times to leach it.

Temperature and draughts. Iowa State names temperature fluctuations and draughts among the causes of leaf problems. A peace lily beside a cold window or an air-conditioning vent will sulk.

Being pot-bound. A plant that has filled its container dries out unusually fast and wilts within a day or two of watering. If it needs water every second day, check the root ball.

Too much light. Peace lilies are genuinely low-light tolerant. Direct sun scorches them, and a plant in a bright window may wilt in the afternoon simply from transpiring faster than its roots can supply.