In biology, the BBCH-scale for bulb vegetables describes the phenological development of bulb vegetable plants, such as onion, leek, garlic and shallot, using the BBCH-scale.
The phenological growth stages and BBCH-identification keys of bulb vegetables are: Roots appearing2 Green shoot visible2 70% of the expected shaft length and diameter reached4 Growth complete; length and stem diameter typical for variety reached4 1 Seed sown 2 Onion sets, shallot and garlic 3 For onions, garlic 4 For leek