Propagation of Eastern Redbud (Cercis canadensis) by Stem Cuttings is Influenced by Clone and Date of Cutting Collection

Abstract

Abstract Stem cuttings of four popular clones of eastern redbud (Cercis canadensis L. ‘Ace of Hearts’, ‘Appalachian Red’, ‘Hearts of Gold’, and ‘Forest Pansy’) were taken on seven dates following budbreak during Spring and Summer 2007 and evaluated for rooting potential. Rooting was affected by a clone and cutting date interaction, indicating the optimum time to take cuttings was different for each clone. Cuttings of ‘Ace of Hearts’ taken 6 weeks after budbreak (WAB) rooted at 75 and 71% when treated with the potassium (K) salt (K-salt) of indolebutyric acid (K-IBA) at 5000 mg·liter−1 (ppm) or 15,000 mg·liter−1, respectively. In contrast, cuttings of ‘Appalachian Red’ rooted at 96 and 93% when taken 15 WAB, the last date tested for that clone, and treated with K-IBA at 5000 mg·liter−1 or 15,000 mg·liter−1, respectively. When taken 8 WAB and treated with K-IBA at 5000 mg·liter−1 or 15,000 mg·liter−1, cuttings of ‘Hearts of Gold’ rooted at 42 and 58%, respectively. Cuttings of ‘Forest Pansy’ rooted poorly regardless of collection date or K-IBA treatment. Treatment of ‘Ace of Hearts’, ‘Appalachian Red’, and ‘Hearts of Gold’ with higher K-IBA rates generally did not increase rooting percentages, but often resulted in more robust root systems. Propagation by stem cuttings may be feasible for some clones of eastern redbud, but separate protocols are necessary for each clone.