My Sansevieria plant was great for almost a year. A couple days ago I noticed this (looks as if leaves are drying out from the inside). How should I treat it now and what I did wrong with it? Appreciate any ideas about it.
Sansevieria can suffer from insects or fungi on the leaves but only rarely - this is mainly because the leaf surfaces are quite hard, shiny and smooth which makes it difficult for piercing or biting insects or spores to get started. If pests do attack it is most likely on roots or very young leaves, that is the soft tissues.
This injury is most likely a watering issue, that is at some time it has become too wet at the roots for too long. This species prefers to live in a very well drained soil with sand mixed in and clear drainage holes in the bottom of the pot for excess water to drain away. Water the plant sparingly, more frequently in summer than in winter. If you have the confidence, carefully pop the plant from the pot and check the roots particularly at the base of the leaves affected and see if there are obvious signs or smells that indicate something wrong.