37 Environmental Predictors of Flowering Time in Waratahs R. McConchie 1 , B. Woodward 1 , B. Gollnow 2 , C.A. Offord 3 , A. Bokshi 1 and P. Geelan-Small 1 1 Faculty of Agriculture and Environment, The University of Sydney, NSW 2006, Australia 2 51 Griffiths Ave, Camden South, NSW 2570, Australia 3 Royal Botanic Gardens and Domain Trust, The Australian Botanic Garden, Mount Annan, NSW 2567, Australia Keywords: temperature, altitude, seasonal flowering Abstract The New South Wales (NSW) waratah, or Telopea speciosissima, is endemic to eastern Australia and is well known as the floral emblem of NSW. Waratahs flower within a six to eight week window in Spring. Several cultivars of T. speciosissima and hybrids from T. speciosissima and T. mongaensis have been selected to extend the flowering season and to provide an array of colours from whites, to pinks and reds. While they can potentially fill a highly profitable niche in the Christmas market, the current short flowering season prevents this from being a reality for growers. Research relating to other members of the Proteaceae family, suggests that flowering may be manipulated in waratahs, allowing the flowering season to be extended to the lucrative Christmas market. There is very little published information about when the main cultivars flower in different growing locations. As part of a larger study into waratah flowering, a grower survey was undertaken to investigate the peak time of flowering for three main cultivars in different regions in Australia. The results from one season suggest that timing of flowering for all cultivars is related to latitude and altitude. Waratahs grown at high altitudes, or at the more southern latitudes, consistently flowered later in the 2010 season. This opens up the possibility for more southerly locations such as Tasmania to fill the Christmas market. INTRODUCTION Telopea spp., are endemic to eastern Australia, and grow naturally on low phosphate sandy loam soils. In 1995 the Rural Industry and Development Corporation (RIRDC) of Australia nominated the waratah as the Eastern Australian “feature species” with the greatest commercial potential. Fifteen years later, this potential is still not fully realised due to the poor understanding of environmental cues that control flowering. Waratahs present a unique opportunity to the Australian cut flower industry. It has been suggested that they have the potential to fill a lucrative niche in the Christmas market; however the current short flowering season of four to six weeks in September to October prevents this. Growers are instead faced with unpredictable yields and inconsistent quality. Research relating to other members of the Proteaceae family suggests that flowering can be manipulated through various management strategies (Hoffman et al., 2009), allowing the flowering season to be extended to the Christmas market. As a preliminary study we investigated the influence of different altitudes and latitudes on the flowering time of three commonly grown waratah cultivars. MATERIALS AND METHODS A grower survey conducted during 2011 and was designed to gather data on timing of anthesis for three waratah cultivars: ‘Wirrimbirra White’, ‘Fire and Brimstone’ and ‘Corroboree’, grown in different locations for the 2010 season. Data were collected from waratah growers along the east coast as provided by the Wildflower Industry Network (WIN) with questions centred on the number of saleable blooms harvested and the average number of blooms harvested in each week of the flowering period. Proc. XI th Intl. Protea Research Symp. Eds.: E.W. Hoffman and F. Schiappacasse Acta Hort. 1031, ISHS 2014