Japanese Stewartia, Stewartia pseudocamellia (Maxim.), cuttings were rooted and seeds germinated to compare growth and survival of the two plant types. Softwood cuttings collected from 18-month-old, 1 to 1.3 m (3 to 4 ft) tall stock plants were rooted successfully (greater than 64%) at two propagation times by giving severed cuttings a basal quick dip in 0.1 M ascorbic or caffeic acid, before a basal quick dip in 100 ppm indolebutyric acid (IBA). Cuttings were overwintered in either a minimum heat (3C, 35F) polyhouse (89% survival), or in a 7C (45F) cooler (97% survival). There was no difference in height following overwintering, but by the end of the first growing season following propagation, seedlings were significantly taller than rooted cuttings, 84 vs 72 cm (33 vs 28 in), respectively. Although growth was vigorous, survival after upcanning was poor; rooted cutting survival was 17%, seedling survival was 48%. This study demonstrates that Japanese Stewartia can be propagated readily by softwood and semi-hardwood stem cuttings dipped in low IBA concentrations if cuttings are pre-treated with either ascorbic or caffeic acid. These cuttings can also be overwintered successfully.
Manuscript Number 98-23.