Buddleja × weyeriana 'Sungold'
|Buddleja × weyeriana|
'Sungold', Longstock Park, UK
Buddleja × weyeriana 'Sungold' is a cultivar which arose as a sport of 'Golden Glow' at the nursery of P. G. Zwijnenburg in the Netherlands during the 1960s.  'Sungold' was accorded the Royal Horticultural Society Award of Garden Merit (record 690)  in 1993, reaffirmed in 2010. A particularly floriferous specimen of 'Sungold' was introduced to the USA from Scotland by Mike Dirr in 1995, and propagated there as 'Honeycomb'; it later came top in the public poll of 57 Buddleja species and cultivars conducted by the University of Georgia in 1997. 
'Sungold' is a vigorous shrub growing to a height of 2 metres (6 ft 7 in) if hard-pruned annually, bearing small panicles of rich golden-orange flowers, the panicles acute at the apex, further distinguishing the clone from 'Golden Glow'. Occasionally, near-white secondary panicles appear as sports near the end of the flowering season. The leaves are of average size for the hybrid, and mid-green in colour. The nectar of B. × weyeriana is relatively complex, comprising three constituents in almost equal proportions: sucrose, fructose, and glucose, whereas the nectar of the common Buddleja davidii is almost exclusively sucrose.
- Hatch, L. (2007). Cultivars of Woody Plants. Vol. 1 (A-G) 2007 Edition. TCR Press Horticultural PDF. books.
- Bean, W. J. (1914). Trees and shrubs hardy in the British Isles. Eighth edition, revised by D. L. Clarke, 1989. Vol. 1, A-C. Murray, London.
- De Vogel, P (1967). Keuringen 1966. Dendroflora 4 (Jan 1967): 61
- Royal Horticultural Society (2010). Trials Report 2008-2010 Buddleja davidii and its close hybrids. Trials Office, The Royal Horticultural Society Garden, Wisley.
- "RHS Plant Selector - Buddleja × weyeriana 'Sungold'". Retrieved 18 June 2013.
- Moore, P. (2012). Buddleja List 2011-2012 Longstock Park Nursery. Longstock Park Nursery, UK.
- Stuart, D. (2006). Buddlejas. RHS Plant Collector Guide. Timber Press, Oregon. ISBN 978-0-88192-688-0
- Percival, M. (1961). Types of nectar in angiosperms. New Phytol. 60: 235-281. 1965. Pergamon Press, London.
- Norman, E. M. (2000). Buddlejaceae. Flora Neotropica 81. New York Botanical Garden, USA
|This Scrophulariaceae article is a stub. You can help Wikipedia by expanding it.|