Confederate rose, also known as cottonmallow or dixie rosemallow, is an old-fashioned plant that was once commonly grown throughout the southern United States, although the species is native to southeastern China (Flora of China Editorial Committee, 2006; Scheper, 2003; Welch, 2009). Often considered a “pass-along” plant because of its distribution through friends and neighbors, confederate rose is popular for its large, soft, gray-green foliage during the summer, and large, showy flowers produced late in the season when few other plants are in bloom (Russ, 2007).
Confederate rose is hardy in USDA zones 7 to 9 (Scheper, 2003). Plants grow as large shrubs or small trees in warmer areas, dropping their leaves in winter and leafing out on old stems in the spring (Russ, 2007). Plants behave more like herbaceous perennials in the colder parts of their hardiness range, producing new flowering branches from a woody base or short trunk each year (Editors of Sunset Books and Sunset Magazine, 1997). Plants will grow to 15 ft high and 10 ft wide in frost-free areas and 6 to 8 ft in areas with hard freezes (Knox and Schoellhorn, 2011).
Plants of confederate rose flower from late summer to early fall, with flowers clustered near the ends of the branches (Liberty Hyde Bailey Hortorium, 1976; Scheper, 2003). The 6- to 10-inch-wide flowers open white or pink and darken as they age over about 3 d, resulting in multiple flower colors on the same plant. Commonly grown cultivars are Flora Plena, with double white flowers, and Rubra, of shorter stature and with deep pink to carmine flowers (Knox and Schoellhorn, 2011).
Confederate rose has been used in breeding programs to produce interspecific hybrids (Wise, 1973). Current hybridization efforts at the USDA-Agricultural Research Service (ARS) Thad Cochran Southern Horticultural Laboratory in Poplarville, MS, aim to develop clonal selections with improved garden performance, reduced plant height, improved disease resistance, and prolific flower production (C.T. Pounders, personal communication). Based on this author’s experience in commercial nursery propagation, clonal selections of confederate rose may be readily propagated using leafy, semihardwood stem cuttings during the growing season. Confederate rose may also be propagated by tissue culture (Shahzad et al., 2001).
Stem cuttings of confederate rose are reported to root readily (Scheper, 2003), including cuttings taken in the fall (Russ, 2007); however, the requirement of an auxin treatment to promote rooting of the cuttings has not been noted. Comparing rooting of softwood and hardwood cuttings of confederate rose during the winter, spring, and monsoon seasons in India, Pandey and Vaish (1990) determined that optimal rooting could be obtained using hardwood cuttings in the winter. These authors did not report using any auxin treatment.
Propagation of confederate rose from hardwood cuttings collected from stock plants during the winter in areas where stems from the previous season’s growth are not killed by cold winter temperatures would permit maximum use of propagation material for the rapid multiplication of new cultivars by supplementing, or being used in place of, leafy stem cuttings taken during the growing season. Therefore, the objective of the present study was to examine the need for an auxin treatment and basal wounding treatment to optimize rooting of hardwood cuttings of confederate rose. Auxin treatments are commonly used in commercial plant propagation to increase overall rooting percentages, hasten root initiation, increase the number and quality of roots, and encourage uniformity of rooting (Hartmann et al., 2002; Macdonald, 1987). Hardwood cuttings of some ornamental species root readily without any auxin treatment, eliminating one step in commercial propagation (Blythe and Sibley, 2009). Application of auxin is sometimes carried out in conjunction with a wounding treatment to expose more of the cambium tissue to the auxin (Blythe et al., 2007).
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BlytheE.K.SibleyJ.L.TiltK.M.RuterJ.M.2007Methods of auxin application in cutting propagation: A review of 70 years of scientific discovery and commercial practiceJ. Environ. Hort.25166185
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