Rooting Hormone
/ROO-ting HOR-mohn/✂️ Propagation●● Intermediate
Also known as: auxin, IBA, rooting powder
A synthetic or natural plant growth regulator, typically an auxin (indole-3-butyric acid or naphthaleneacetic acid), applied to the cut end of a stem cutting to promote adventitious root development. Rooting hormones come in powder, liquid, and gel formulations at various concentrations for softwood, semi-hardwood, and hardwood cuttings. While many easy-to-root species don't require hormone treatment, it significantly improves success with difficult-to-root plants.
Etymology
English root + Greek hormon (setting in motion)
Example
“Dip the base of each cutting in rooting hormone powder, tapping off excess before inserting into the propagation medium.”