Cytokinins are adenine-derived hormones, such as zeatin, made largely in root tips and carried up the xylem. They promote cell division, release axillary buds from apical dominance, delay leaf senescence, and with auxin set whether tissue makes shoots or roots. Synthetic forms such as kinetin and 6-benzylaminopurine (BAP) are widely used in tissue culture.
In practice
Growers rarely apply cytokinins directly, but the hormone links root health and shoot growth. A big, active root system supplies more cytokinin, which supports leafy, branchy growth and keeps leaves green longer. Root damage, cold or waterlogged roots cut cytokinin supply, and part of the slowdown you see is hormonal.
In micropropagation, a high cytokinin-to-auxin ratio in the medium drives shoot multiplication; reversing the ratio drives rooting.
Seaweed extracts are often marketed as "cytokinin-rich". Concentrations and effects in cannabis are not well documented. Treat claims cautiously.
Don't confuse with
- Auxin: promotes roots and apical dominance; often the counterweight.
- Gibberellin: drives elongation rather than division.
- Abscisic acid: a stress and dormancy hormone, broadly opposite in effect.
