this one is ready for planting, mate, when the taproot is about 0.5cm, it's ready to go.

but, i see in the pic you're holding the bare taproot with your hands. you should use a pair of tweezers to do that, the taproot is the most delicate part of the plant wouldn't wanna get it ruined, ey
good luck, harv

ps put it in soil/other medium with the taproot down