Method and apparatus for enhancing reliability and integrity of data stored in a non-volatile memory, such as in a solid-state drive (SSD) having an array of flash memory cells. In accordance with various embodiments, a controller is adapted to harden data stored in a first location of said memory in relation to a detected loss of retention characteristics of the first location. In some embodiments, the data are hardened by storing redundancy information associated with said data in a second location of said memory. The redundancy information can be a redundant set of the data or higher level error correct codes (ECC). The hardened data can be recovered to the host during a read operation by accessing the data stored in both the first and second locations.