Leaf droop alone cannot name the cause, so I lift the plant out and read the roots the same day. Firm white tissue stays, anything soft goes, and a base that gives under a thumb ends the rescue there. What follows is subtraction: less water, no feed, steady light.
Leaves keep coming and no spike ever rises, which looks like a mystery and is really a number. I check the light at leaf height first, then the size of the clump, then leave the peace lily alone for one full growth cycle before I judge whether anything changed.
A limp plant straight after a move is not automatically a failure, so I water it through once and come back an hour later. Lifting means it was dry. Staying flat means the roots have stopped drawing, and the two weeks that follow are about subtracting rather than adding.
There is no stem to cut back on this plant, so a stretched peace lily is fixed by moving it rather than by trimming it. I hold the newest leaf against an oldest one, read the stalk length and the color, then find the pot a brighter spot and turn it every watering.
I name the insect by where it sits before I reach for anything, because position separates the three peace lily pests in one look. Then the order matters more than the product: isolate the plant, take the insects off by hand, and use a single agent in one room.
Leaf cuttings do not work on this plant, so propagating a peace lily means splitting the clump rather than rooting a blade. I water 1 day ahead so the root ball comes out damp, brush the surface back to find where the fans already separate, and give every piece roots of its own.
Three visible traits name a selection, and I read them in order: the white marking pattern, then the blade surface, then two measurements taken with a plain rule. No flower is needed and no root ball comes out of the pot, which is why an unlabeled shelf plant is rarely a mystery.
Cut tissue never grows back, so I finish all three looks before a blade touches the leaf. Where the mark sits, whether it has stopped spreading, and how it feels under a thumb name the cause between dry air, salt in the water and a sun-struck patch on my peace lily.
The surface lies, so I stopped watering to a calendar and started reading the pot instead. A lift the day I water and another three days later builds a scale nothing else can give me, and the pour ends when the saucer fills rather than at a measured volume.
A peace lily stores no water of its own, so everything the roots draw on has to come from the medium around them. No bag prints the number that actually decides it, which is how much air that blend still holds, and I have learned to settle it by hand.