|WITCHER, ANTHONY - Tennessee State University|
|ARNOLD, MIKE - Texas A&M University|
Submitted to: HortScience
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/17/2018
Publication Date: 4/24/2018
Citation: Alexander, L.W., Witcher, A., Arnold, M. 2018. Hamamelis virginiana ‘Sunglow’. HortScience. 53(4):575-577.
Interpretive Summary: Witchhazels are planted in the landscape primarily for their adaptation to diverse environments and their fragrant and unusual flowers which consist of four strap-like petals. However, widespread planting of witchhazel is hampered by nursery production difficulties and a large irregular, open form of many cultivars. Other limitations of witchhazel, especially H. virginiana, include leggy, spreading forms, leaf retention during flowering, and susceptibility to foliar diseases such as powdery mildew and leaf blight in nursery production in the eastern and southeastern U.S. Improved cultivars are needed that are easy to propagate, are disease resistant, have abundant flowers, and don’t retain foliage during the flowering period. To that end, scientists in McMinnville, TN selected a new witchhazel, Hamamelis virginiana ‘Sunglow’, with large, abundant bright-yellow flowers, upright growth habit, and disease tolerant foliage. ‘Sunglow’ is well suited to a variety of landscape uses, including as background plantings in the shrub border, specimen plants, as a deciduous hedge or screen, mass planted in larger areas, or as part of a native plants display garden. The dense floral display, upright habit, small spread (only 3 feet wide after 12 years), and lack of root sprouting makes ‘Sunglow’ an attractive choice for residential landscapes.
Technical Abstract: An upright, dense-blooming American witchhazel cultivar (Hamamelis virginiana L. ‘Sunglow’) was released by the U.S. National Arboretum. ‘Sunglow’ has grown 6.5 m high and 2.4 m wide in 12 years in McMinnville, TN. Yellow fall leaf color develops in mid-autumn. In late autumn, ‘Sunglow’ is covered with dense, lemon-yellow inflorescences that remain as the plant defoliates. This cultivar is hardy in USDA hardiness zones 4 to 8 and can be grown in full sun through shade. This new release is well suited to a variety of landscape uses, including as background plantings in the shrub border, specimen plants, as a deciduous hedge or screen, mass planted in larger areas, in fragrance gardens or as part of a native plants display garden. Compared with other Hamamelis L. cultivars, ‘Sunglow’ exhibits good field tolerance to powdery mildew in warmer climates where this disease is a problem. This cultivar was selected for its upright habit, large, profuse blooms, continued bloom after leaf drop, lack of root sprouts, foliar disease resistance, and ease of propagation. Softwood and semi-hardwood cuttings of ‘Sunglow’ rooted at an average rate of 80% and 63%, respectively, in preliminary studies. Lack of root sprouts ensures this cultivar may be used as a rootstock or own-rooted, which offers flexibility and appeal to growers. ‘Sunglow’ will be available to the retail market in 2019.