Yes, it is possible to start dreadlocks with short hair, though it requires more patience and dedication compared to starting with longer hair. You'll need at least 2 to 3 inches of hair length to begin the locking process. Some recommend waiting until you have 4 to 6 inches for easier installation.
It will take several months (6 months to 1 year) for the short starter dreadlocks to mature and gain significant length. The initial dreadlocks will be short and stubby.
Maintaining short starter dreadlocks requires more frequent re-twisting, palm rolling, and careful washing to keep them from unraveling. Using dreadlock wax or gel can help the short hair lock together.