Rooting and initial establishment of stem cuttings of oregano, peppermint and balm

Stem cuttings of 3 Labiatae spices, oregano (Origanum vulgare L.), peppermint (Mentha piperita L.) and balm (Melissa offinicalis L.) were analyzed for their rooting- patterns and initial establishment under controlled conditions. Approximately 100% of cuttings from all 3 species rooted, but the number of roots per cutting varied in the order: oregano 〉 balm 〉 peppermint. Treatment of cuttings with IBA, IAA and Hormex increased both the number of roots per cutting and the rate of root formation in all 3 species. This effect was, however, dependent on their natural capacity for root formation, with the greatest effect on the slowest root producer, balm, where root number increased 3-fold. Enhanced root formation was reflected in increased fresh-weight accumulation by both root and shoot systems. Hormone treatment also increased shoot length of peppermint. All the above mentioned effects were concentration-dependent. Thus, hormonal treatment of cuttings of these 3 Labiatae spices clearly aided early establishment, and especially so in cuttings which were initially less vigorous.