Submitted to: HortScience
Publication Type: Abstract Only
Publication Acceptance Date: March 31, 2005
Publication Date: July 7, 2005
Citation: Jones, K., Reed, S. 2005. Hybridization of Hydrangea arborescens and H. involucrata. HortScience. 40:1002. Technical Abstract: Hydrangea arborescens L., or smooth hydrangea, is a shrub native to the eastern United States that produces large corymbs of pure white flowers in early summer. Rated as hardy to USDA cold hardiness zone 4, it is one of the most cold-hardy members of the genus. Hydrangea involucrata Sieb. is an Asian species that produces lavender-blue flowers in mid-summer. This species, which is not widely cultivated in the U.S., is only rated as hardy to zone 6 to 7. The objective of this study was to hybridize H. arborescens and H. involucrata for the purpose of combining cold hardiness and flower color. Reciprocal crosses were made between H. involucrata and H. arborescens during summer 2003. No seed were obtained when H. involucrata was used as the maternal parent. Approximately 500 seed were collected from H. arborescens × H. involucrata hybridizations, 36 of which germinated. Several of these seedlings were extremely weak and died at a young age. The remaining 8 plants have not flowered and all possess reduced growth rates. Hybridity was verified using RAPD markers and morphological comparisons of hybrids and parents.