Influence of interaction (P = 0.0027) between lavandin (Lavandula x intermedia) cultivar and media across all plant growth regulator (PGR) treatments on mean cutting adventitious root length (A, B, C). Different letters indicate significant cultivar x media effect. In addition, influence of PGR concentration on adventitious root length of lavandin cuttings (D) across lavandin cultivar and media treatments. Different letters indicate significant PGR effect (P = 0.0006). Error bars represent SE of the mean. Data pooled from fall 2019 and spring 2020 experiments.