Most dreads will lock in about three to six months, but it really depends on the softness of the hair. If the hair is very soft or was previously relaxed, it can take approximately a year or so to lock.
Waiting for dreads to lock is a long process that takes a lot of patience. Dreads that are under a year old are considered young. Only when dreads mature can their owner truly reap the benefits of the locking process. New dreads go through many stages within the first year, and many people with new dreadlocks give up. Continued palm rolling through the first six months helps dreads to lock more quickly.