Botanic Gardens Trust, Sydney, Australia

Growing waratahs

Description

The New South Wales Waratah Telopea speciosissima is a large, long-lived shrub or tree that generally grows to about 3 m tall. It may reach 5 m in the absence of the fires - however, fires are common in its natural habitat. After a fire a waratah can regenerate from a ‘lignotuber’ - a woody swelling of its stem that lies partly or wholly under the ground.

Cultivation

  • Transplant in autumn to a wind protected area.
  • Partially shaded with morning sun is best, although waratahs will grow in full sun.
  • Plant at least 1.5 m apart or into very large pots.
  • Mulch soil with composted leaf mulch to prevent roots drying out.
  • Waratahs need regular watering. The roots should never be allowed to dry out, however they hate ‘wet feet’ - so ensure their medium is free draining (whether in a container or in the ground). It can be beneficial to mound up topsoil - to 0.5 m high - and to incorporate leaf mulch into the soil. You can see an example of mounding with sand in the Banksia Garden at the Australian Botanic Garden Mount Annan.
  • Fertilise with a low-phosphorus slow-release fertiliser or 'blood and bone' in late winter or early spring.
  • Cultivated waratahs require heavy pruning once established. About 3/4 of the plant should be removed immediately after flowering to reinvigorate the plants. New shoots should flower the following year. Prune off any weak stems as this will stimulate re-shooting.

Propagation

  • The easiest way to propagate waratahs is from seed - the fresher the better - but it is also possible to strike them from cuttings.
  • Seedling plants take about five years to flower, while cuttings may take only two years.
  • Seed pods take about six months to mature, at which time they turn brown and split open.
  • Seeds are winged for wind dispersal and there may be more than 250 seeds on one flowerhead in a good year.

Sowing the seeds

  • Sow seeds in a pot filled with a well-drained seed raising mix, cover with a fine layer of mix and water well.
  • Transplant seedlings into a freely draining potting mix that does not contain any added nutrients.
  • Add some slow-release low phosphorus fertiliser several weeks later.

Flowering

  • Waratahs flower over a six-week period in spring (September-October) in the Sydney region, but later in cooler areas. The size and shape of the blooms of the New South Wales Waratah can very considerably, as can the range of naturally occurring colours, although the majority are red and pink.
  • A commercially available white variety known as 'Wirrimbirra White' is not true white but a creamy yellow or greenish colour.
  • The main pollinators of waratahs are birds, which are attracted by the copious amounts of nectar and bright colours.

Bract browning

Bract browning is a problem affecting the quality of waratah flowers and is considered by the cut-flower industry to be the most serious impediment to the development of an export market for the product. Bract browning occurs prior to harvest and affects the showy floral bracts surrounding the inflorescence. Research into the causes of bract browning have shown that the problem is caused by sun exposure and can be reduced by protecting plants with 50% shade cloth. The shade cloth reduces light damage (photoinhibition) and destruction of pigment in the bracts. The recommendations from this research have been adopted by the cut-flower industry and have resulted in a measurable increase in the quality and profitability of products sold on the international market.

Natural habitat

The NSW Waratah grows naturally in patches of sandy loam on ridges and plateaus in the Sydney geological basin, the Central and South Coast districts and the Blue Mountains of New South Wales.

History

Waratahs feature in Aboriginal legend. They were also used by early European settlers for basket-making - among other uses - and they are depicted in many everyday items such as paintings and pottery. They have been used for company logos and as architectural ornamentation, and the name has been used for towns, steamships and even football teams.

Naming

The common name ‘Waratah’ was coined by Australian Aborigines and means ‘red-flowering tree’. The botanical name ‘Telopea’ means ‘seen from afar’, and ‘speciosissima’ means 'most beautiful'. The Waratah truly is a most beautiful plant, especially when in flower, and was described by early botanists as the ‘most magnificent plant’ in New Holland. Now symbolically instated as the floral emblem of NSW, the Waratah has become arguably the most famous and recognisable Australian plant.

Conservation

The New South Wales Waratah was once abundant in many areas of the Sydney metropolitan area, and the species’ survival is now due to its existence in national parks, reserves and relatively inaccessible areas.

Please don't pick waratahs when you see them growing in the bush. Apart from depriving others of the enjoyment of seeing them in their natural habitat, this practice depletes natural seed reserves and often results in poor quality blooms compared with those from well-cultivated plants.

Research

The New South Wales Waratah (Telopea speciosissima) is extremely variable in flower form, size and colour, leaf shape and density, plant vigour and flower production. This variability has no doubt helped it to survive, but it makes the commercial selection and development difficult. Cathy Offord, our Horticultural Research Officer based at the Australian Botanic Garden, has worked on the horticulture of waratahs for the past eight years and is continuing her involvement in the conservation and horticulture of Australian plant species.

Other species of waratahs

The NSW Waratah is not the only species of Telopea. All the other species of waratah grow on Australia's eastern seaboard and have smaller and less spectacular blooms than Telopea speciosissima. They are the Gibraltar Range Waratah (Telopea aspera), the Braidwood Waratah (Telopea mongaensis), the Gippsland Waratah (Telopea oreades), the Tasmanian Waratah (Telopea truncata).

A number of cultivars are also available, such as ‘Wirrimbirra White’ and ‘Shady Lady’.

References

General Publications

  • Nice, R. (2000). State of the waratah : the floral emblem of New South Wales in legend, art & industry : an illustrated souvenir. Royal Botanic Gardens, 62p.
  • Nixon, P. (1997) The Waratah. Kangaroo Press, 96 p.
  • Offord, C.A. (1993).  The magnificent waratah.  Australian Natural History 24(6): 46-52
  • Offord, C.A. (1996c). Waratahs.  In ‘Horticulture of Australian Plants’.  (Eds M. Burchett and K. Johnston). pp. 67-81. (UNSW Press: Sydney).

Scientific Publications

  • Donovan, N.J., Offord, C.A. and Tyler, J.L.  (1999). Vegetative cutting and in vitro propagation of the tree waratah, Alloxylon flammeum  P.Weston and Crisp (Proteaceae).  Australian Journal of Experimental Agriculture. 39: 225-229.
  • Martyn, A., Thomas, C., Gollnow, B., Offord, C. and McConchie, R. (2003).  Effect of shade cloth, irrigation frequency and calcium sprays on bract browning in waratahs (Telopea spp.). Acta Horticulturae 602: 99-102.
  • Martyn, A.J., Gollnow, B., McConchie, R. and Offord, C. A. (2007). Characterisation of bract browning and the effect of shade on browning in waratah (Telopea spp., Proteaceae) cultivars ‘Fire and Brimstone’, ‘Olympic Flame’ and ‘Wirrimbirra White’. Scientia Horticulturae 112: 427-433.
  • Martyn, A.J., Larkum, A.W.D., McConchie, R. and Offord, C. A. (2008). Photoinhibition and change in pigments associated with bract browning in waratahs (Telopea spp., Proteaceae). Journal of Horticultural Science and Biotechnology 83 (3): 367-373.
  • Martyn, A.J., Thomas, C. R., O’Neill, M. E., Offord, C. A. and McConchie, R. (2007). Bract browning in waratahs (Telopea spp.) is not a localised calcium deficiency disorder. Scientia Horticulturae 112: 434-438.
  • McConchie, R., Martyn, A. and Offord, C. (2005). Effect of shade on bract browning of waratahs (Telopea spp.) Acta Horticulturae 694: 439-443
  • Offord, C.A. (1997).  Tissue culture of waratahs. In ‘The Waratah’. Nixon, P.  2nd ed. pp. 49-50. (Kangaroo Press: Sydney).
  • Offord, C.A. (2003).  Improvement of waratahs (Telopea spp.) through breeding.  Acta Horticulturae 602: 119-122.
  • Offord, C.A. (2004).  An examination of the reproductive biology of Telopea speciosissima (Proteaceae) with emphasis on the role of protandry and self-pollination in fruit set.  International Journal of Plant Sciences 165 (1):  73-83.
  • Offord, C.A. (2006).  Analysis of characters and germplasm of significance to improvement of Australian native waratahs (Telopea spp., family Proteaceae) for cut flower production.  Genetic Resources and Crop Evolution 53: 1263-1272.
  • Offord, C.A. (2008).  Effects of temperature on pollen viability and flower opening in waratah (Telopea speciosissima R.Br.).  Acta Horticulturae 805:99-106.
  • Offord, C.A. (2008).  Low fruit and seed set of waratah (Telopea speciosissima R.Br.: implications for breeding.  Acta Horticulturae 805:93-98.
  • Offord, C.A. and Campbell, L.C. (1992).  Micropropagation of Telopea speciosissima R.Br (Proteaceae) 2: Rhizogenesis and acclimatisation to ex vitro conditions, Plant Cell Tissue and Organ Culture 29: 223-230.
  • Offord, C.A., Campbell, L.C. and Mullins, M.G. (1992).  Micropropagation of Telopea speciosissima R.Br (Proteaceae) 1: Explant establishment and proliferation, Plant Cell Tissue and Organ Culture 29: 215-221.

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Olympic Flame

Waratah cultivar

Waratah cultivar

Waratahs

State of the Waratah

Waratah scarf