Hydrangea (Hydrangea macrophylla) is popular for landscaping and as a flowering potted plant. According to the U.S. Department of Agriculture, sales in the United States increased from 2009 to 2019, and the wholesale value reached $154 million in 2019. Hydrangea chinensis is an evergreen shrub native to subtropical regions of south and southeast Asia. This plant species is commonly seen in forests at low altitudes in Taiwan, flowers naturally in early spring, and could be used as a parent to breed and select early-flowering hydrangea progenies.
Researchers from the National Chung Hsing University in Taiwan obtained several interspecific early-flowering hydrangea progenies from crossing Hydrangea chinensis and H. macrophylla cultivars.
New early-flowering hydrangea cultivars/lines are desirable because tropical and subtropical growers are anxious to reduce the hydrangea susceptibility to wilting in summer. In subtropical areas, growers can force some hydrangeas to flower for the Chinese New Year market; however, this off-seasonal production has practical difficulties because of global warming and increased energy costs.
Hydrangea hybrid HB01C-01, derived from H. macrophylla ‘Freudenstein’ × H. chinensis, and CHR06-09, derived from H. chinensis × H. macrophylla ‘Leuchtfeuer,’ were selected for their vigorous growth and inflorescence appearance.
Hydrangea chinensis and the hybrid seedlings flowered starting from February and March, respectively, which is earlier than that of H. macrophylla ‘Leuchtfeuer’ and ‘Freudenstein’ in May in greenhouse conditions. Hydrangea chinensis have white sepals, and the two H. macrophylla cultivars have deep pink ones, whereas most of the hybrid plants have white or light pink sepals, and few hybrids have pink sepals.
Hydrangea hybrid HB01C-01 is suitable for landscape use because of its height, vigorous growth, and white decorative sepals that brighten a shade garden. Hydrangea hybrid CHR06-09 is suitable for potted flowering plants because it has multiple compact branches, large decorative sepals, and smaller leaves.
The full study results can be found on the ASHS HortScience electronic journal website at: https://doi.org/10.21273/HORTSCI16840-22.
Established in 1903, the American Society for Horticultural Science is recognized around the world as one of the most respected and influential professional societies for horticultural scientists. ASHS is committed to promoting and encouraging national and international interest in scientific research and education in all branches of horticulture.
Comprised of thousands of members worldwide, ASHS represents a broad cross-section of the horticultural community — scientists, educators, students, landscape and turf managers, government, extension agents, and industry professionals. ASHS members focus on practices and problems in horticulture: breeding, propagation, production and management, harvesting, handling and storage, processing, marketing, and use of horticultural plants and products.
To learn more, visit www.ashs.org.