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 (1997) 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 (1963) 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.
Cultivars A number of selected forms of
T. speciosissima and hybrids with other
Telopea species are being brought into cultivation. These exhibit variations in the colour of the flowers and/or the bracts. Some examples include: • 'Fire 'n' Ice' – red with white tips • 'Songlines' – pink in bud, opening flame red • 'Dreaming' – styles open white and mature to pink • 'Shade of Pale' – cream tinged with pink • 'Brimstone Blush' – red with a pink blush • 'Braidwood Brilliant' – red (
T. speciosissima x
T. mongaensis) • 'Wirrimbirra White' – almost pure white • 'Shady Lady' – blood red (
T. speciosissima x
T. oreades)
Issues of cultivation Issues with cultivation occur throughout the growth cycle of
Telopea spp. with the first issues being encountered at the seedling stage. Waratah seedlings are often associated with a common plant condition known as
damping off. Damping off is a condition that causes the death of seeds or seedlings facilitated by a number of different fungal pathogens. A given seed can become infected with a fungus, often causing it to darken and soften, killing the seedling before it emerges or causing it to emerge in a pre-weakened state. Seedlings can also be infected after emergence resulting in the stem thinning until it eventually rots and the seedling topples over. The problem is often associated with and encouraged by excessively wet conditions. Another major issue for production is
bract browning – a discolouration of the showy floral bracts of the floral head occurring prior to harvest. Bract browning has been a major restraint to financial returns due to reduced cut flower quality. Browning is usually a result of sun damage but can also be associated with wind burn. The addition of shade cloths to crop management strategies has been shown to reduce levels of excessive light and has significantly minimised financial losses due to the reduction of occurrence of bract browning. In the natural state, the waratah does not compete very well with surrounding shrubs and is at its best after fire when competition is removed. This means that
weed presence during cultivation has a profound effect on growth, particularly when the waratahs are small. Weeds should be seriously tended to in the early stages of growth. Once plants have reached waist height cases should be analysed individually to determine the best method of weed control. In New South Wales the most destructive pest to waratah crops is the macadamia twig girdler (
Neodrepta luteotactella). The damage is caused by the larvae and damage generally first shows at a branch fork or leaf. The condition is generally confined to young shrubs or trees. The leaves are skeletonised and the larvae web them together into a shelter that incorporates larval faeces. Larvae can also burrow into the developing flower head, obliterating a crop entirely if left uncontrolled. Biological control methods include encouragement of bird species. The borer is present throughout the year and so pesticide treatments with a strong persistent spray should be carried out monthly. What is used for the borer should also control lesser pests such as
white scale, which is common in the natural state, and
Macadamia leafminer (
Acocercops chionosema). Leafminer poses no threat to the life of the plant but it is preferred that stems for the market still have leaves attached. Thus damaged leaves lower the value of the crop. Chemicals with zylene or toluene should not be used as the will not be tolerated by the plant. There are also issues of
fungal infection. Oomycete and fungal species cause stem rot (
Phytophthora spp.) and root rot (
Rhizoctonia spp.) that can ultimately cause plant death but can usually be controlled by adequate drainage. A problem for production that emanates from within the plant is the high amount of genetic and therefore morphological variability present in the flowers produced. The need to lift the quality and consistency of cut flower product has been repeatedly highlighted by industry reviews. Inconsistency of product is a key impediment to further industry growth. ==Floral morphology==