I have a mature peace lily plant that is developing a sticky sap on the leaves.. What could be the cause and cure?
The sap is dripping onto the surrounding floor.
Certified GKH Gardening Expert
The dripping is likely to be "honeydew" excretions from a sucking insect pest, probably aphids.
Inspect the leaves and especially the under sides. You can wipe the pests off with a rag or wet sponge to minimize the infestation and nuisance.
You can use neem oil to treat the plant.