Waratah


The waratah is an Australian-endemic genus of five species of large shrubs to small trees, native to the southeastern parts of Australia. The best-known species in this genus is Telopea speciosissima, which has bright red flowers and is the New South Wales state emblem. The waratah is a member of the family Proteaceae, flowering plants distributed in the Southern Hemisphere. The key diagnostic feature of Proteaceae is the inflorescence, which is often very large, brightly coloured and showy, consisting of many small flowers densely packed into a compact head or spike. Species of waratah boast such inflorescences ranging from 6–15 cm in diameter with a basal ring of coloured bracts. The leaves are spirally arranged, 10–20 cm long and 2–3 cm broad with entire or serrated margins. The name waratah comes from the Eora Aboriginal people, the traditional owners of the Sydney region.

Taxonomy

The genus Telopea belongs to the plant family Proteaceae. Within the Proteaceae, their closest relatives appear to be the genera Alloxylon, Oreocallis and Embothrium, a group of generally terminal red-flowering plants that skirt the southern edges of the Pacific Rim. Together they make up the subtribe Embothriinae. The genus was first described by Robert Brown in 1810 from the type species Telopea speciosissima. There are five species of plant within the genus, all of which readily hybridize in cultivation. There are two main branches, with one being the species pair of T. speciosissima and T. aspera, with the other lineage giving rise to T. truncata first, then T. oreades and T. mongaensis. The speciosissima-aspera lineage has two synapomorphies—distinguishing common characteristics presumed not present in ancestors—leaves with toothed margins, and large red involucral bracts. The truncata-oreades-mongaensis lineage has flowers that open from the centre to the edge of the inflorescence rather than the reverse, which is a feature of the speciosissima-aspera clade and more distant relatives.

Species

The genus Telopea contains five species:
Species of WaratahSpecies of WaratahSpecies of WaratahSpecies of WaratahSpecies of Waratah
Common and binomial namesAuthorityImageDescriptionRange
Gibraltar Range waratah or New England waratah
Crisp & It was split off as a separate species from the NSW waratah by Crisp and Weston in 1987 and in overall appearance is very similar to T. speciosissima.Northeast New South Wales
Braidwood Waratah or Monga waratah
CheelLignotuberous shrub with red flowerheads. Closely related to T, oreades.Southeastern New South Wales
Gippsland waratah or Victorian waratah
F.Muell.Generally a tall shrub to small tree, with red flowerheads. Closely related to T, mongaensis.East Gippsland in Victoria and into far southern New South Wales
New South Wales waratah
R.Br.It is the best-known waratah with its large, bright red inflorescences.East New South Wales
Tasmanian waratah
R.Br.Generally a shrub with red flowerheads.Throughout Tasmania between 600-1200m elevation, and has been brought into cultivation in Tasmania.

Habitat

Species grow as either large shrubs or small trees with spirally arranged leaves with either entire or serrated margins. They prefer sandy loam soils and are a pyrogenic flowering species, meaning that they rely on post-fire flowering followed by production and dispersal of non-dormant seeds to take advantage of favourable growing conditions in the altered environment following a fire.

Distribution

The natural distributions of the five species of Telopea are all confined to east coast regions from northern New South Wales to Tasmania. Each of the species has its own distinctive natural distribution with minimal or no overlap. Climatic changes may have restricted the expansion of species distribution or led to its isolation in a particular region. However, waratahs can also grow outside of these natural distribution areas. Cultivation mostly occurs north of Sydney and in the Dandenong Ranges, Victoria. T. speciosissima has also been grown successfully in areas not on the map. In Australia these areas include south-west Western Australia, the Queensland coast and also Toowoomba. Overseas, New Zealand, the USA, South Africa, and Israel are all also able to grow waratah with varying degrees of success. It was introduced to England in 1789 but cannot survive English winters out of doors except in the south-west coastal regions, and it rarely flowers in glasshouses.

Cultivation

For some time the waratah has had a reputation as a difficult plant. It has a complex culture and for many years there have been cases of people trying to establish the plant only to have the attempt fail. This can be the effect of unsuitable soil conditions, aspect or climate. The waratah is also a slow plant to mature with a flowering period that is short, unpredictable and unreliable. Early issues with cultivation meant that approximately 90% of all waratahs sold at Sydney’s Flemington markets in the early 90s were bush picked. Some progress has been made in the 20 years since then with several cultivars being commercially grown mostly in areas to the North and South of Sydney and in the Dandenong Ranges in Victoria. Issues with cultivation are still present however.

Propagation

The propagation of waratah for commercial production is relatively easy in comparison to other stages of the growth cycle. Plants are usually propagated from cuttings, fresh seed or stored seed. Fresh seed has a good germination rate but deteriorates fairly rapidly unless stored at low temperature and low humidity. Dry seed will last a few years in refrigerated storage but should be treated with a general purpose fungicide prior to storage and at propagation to ensure good germination rates and healthy seedlings. The best time to take cuttings is when the plant is experiencing a flush of growth. The cuttings are taken from firm wood from the last twelve months growth. If plant material is scarce, single nodes can be used for cutting propagation.
Other methods of propagation that are successful but not widely used for commercial production include grafting and tissue culture. Stock for grafting is vigorous and as such is labour-intensive in constant control of stock regrowth from the lignotuber. As such, it is not a recommended method but is useful for the fast growth of limited material. Rootstock and scion combinations are used for many woody perennials to provide the necessary mix of floral or fruit characteristics and cultural requirements.
Tissue culture is very labour-intensive and would likely only be used in the case of rapidly increasing the number of plants from limited or valuable material. The process is complex though as different clones require different optimal culture conditions requiring different developmental work for each clone. There also exists problems with hardening off, with roots and leaves produced in vivo dying off on planting out.
For Telopea plants propagated from seed, the transition from seedling to flower takes about 5 years. Cuttings may take only 2 years. The most common form of propagation is from seed, however, certain varieties and cultivars must be propagated from cuttings if the grower wishes the plants to remain true to form. Fresh seed has a higher viability than cuttings and will germinate 2–3 weeks after sewing.

Commercial cultivation

The overall cultivation of the waratah as a single process is a tricky one as flowering time, number and quality are easily affected by changes in the plant environment. These factors must be considered as early as prior to buying land for production. North facing aspect ensures a maximum of sun exposure. A combination of northerly, easterly and westerly aspects will spread the flowering time with the western slope flowering slightly later on. As the location approaches the equator, flowering time will be earlier. Elevation also has to be considered as it will affect temperature, a major influence on flowering time. More flowers will be produced in full sunlight although better quality flowers are found in the shade. Paul Nixon in his book ‘The Waratah’ claims that ‘the ideal situation is to have rich, well drained, deep soil with a north-easterly aspect giving the plants full sun until the flowers buds have initiated and then put shade cloth over the bushes until they have flowered’.
A primary consideration for cultivation is water drainage. The waratah naturally grows in poor, sandy soils where it thrives due to the soils excellent water draining properties. Drainage properties can be linked to aspect and as a result plants grown on a north easterly aspect will generally flower 1–2 weeks earlier than a westerly aspect at the same location. Watering systems must also be carefully considered to coincide with correct drainage. As an Australian native the waratah is a sturdy plant well adapted to coping with harsh environments and low rainfall. Watering systems are still necessary for cultivation in order to produce a reliable crop and a quality bloom.
In the wild the waratah has become adapted to growing in nutrient-poor soils leading many people to believe that this is what is necessary for the development of the plant. Fertilisers are not necessary for the development of the plant but the waratah has been shown to be receptive to some treatments. Many native plants have been known to have poor establishment in soils with high levels of nitrogen and phosphorus. This coincides with the observation that fertiliser application immediately after transplant of waratahs in the field often leads to high mortalities. Other studies have reported a strong growth response to high nutrient levels, particularly phosphorus. As yet, the details of this response are not yet clear and suggest a complex nitrogen-phosphorus relationship. Earlier work on related species, had indicated that fertiliser application may hasten maturation and give early flowering. If fertiliser is applied, drainage properties of the soil mean that nutrients are quickly leached and so the best application method is multiple applications at critical stages in development such as flush periods.
Pruning is a very important consideration for the commercial growth of waratahs in the effort to design a shape for the plant that will encourage the maximum production of saleable blooms. The aim is to get as many growing tips as possible as it is on these that the flowers will develop.
With the correct mix of factors for cultivation it is possible to produce up to sixty blooms per plant per year. This could translate to up to 20,000 to 50,000 blooms per ha. Waratah inflorescences are harvested when 0–50% of flowers are open, although inflorescences with 0–5% of flower open have the longest vase life and least opportunity for bract damage in the field.