Banksia

Banksia plants belong to a genus of around 170 species native to Australia. They also belong to the Proteaceae plant family, which is an ancient family of flowering plants that dispersed and diversified throughout Gondwana before the supercontinent disintegrated. With about 1600 species, Proteaceae is one of the plant groups that dominate the southern hemisphere flora.

Banksia plants take many forms, from trees up to 30 metres tall, to woody shrubs, to a few prostrate species. The leaves vary greatly between species, with sizes varying from 1.0–1.5 centimetres long up to 45cm long. The young leaves are velvety and often brownish or yellow in colour, while the mature leaves are green or dark green, hard to touch and most species have serrated edges. Leaves are usually arranged along the branches in irregular spirals, but in some species, they are crowded together in whorls.

The most distinguishing feature of banksias is the flower spike, which is an elongated inflorescence consisting of a woody axis covered in tightly-packed pairs of flowers attached at right angles. A single flower spike generally contains hundreds or even thousands of flowers; the most recorded is around 6000 inflorescences in Banksia grandis. A wide range of species and hybrids is available for cultivation, which enables a spread of harvest times throughout the year.

Banksias generally achieve their first commercial harvest three years after establishment. It is therefore important to thoroughly research the entire value chain for banksia production and to select the correct variety or hybrid for the target market.

The wildflower industry, including banksia producers, is a mature industry in Australia. It has an active R&D program that assists industry members develop better production techniques, works towards industry-wide standards and undertakes market development activities. The wildflower industry is represented by WildFlowers Australia, which represents a diverse range of industry participants, including growers, buyers, wholesalers, exporters and importers, and research and extension specialists.

Several species of banksia are used as feature cut flowers in local and international markets. They are usually sold as single stems and provide a focal point in arrangements. The immature flower heads (called “candles”) of some banksias (e.g. B. plagiocarpa) can also be used in floral arrangements.

Growing regions

Most of the commercially grown banksias are native to Western Australia. Suitable climates and soil types for the production are found in the coastal areas of south west Western Australia and the sandier/drier parts of South Australia, Victoria and New South Wales. However, several species originating from eastern Australia are grown, mainly in coastal New South Wales and south east Queensland. These include B. plagiocarpa, B. robur and B. ericifolia.

Soil type

Western Banksias will grow on a variety of soil types from sands to sand over clays. Sandy soils, from deep white-grey sands to the yellow and red sands found in the northern regions of Western Australia, are also suitable. Duplex soils such as sand over gravel are suitable and sandy loam soils have potential, so long as they are free draining. Soils with compacted layers or hardpans should be avoided. It is recommended that soil tests be carried out during site selection to ensure that phosphorus levels are not too high and that the site is free of any serious diseases, particularly phytophthora.

Eastern banksias will grow on most soils, including heavier clay loams, and don’t require the same degree of soil drainage as the western species; B. plagiocarpa comes from the wettest part of the country around Innisfail and B. robur occurs in coastal wetlands.

Climate

Western Australian Banksias grow best in a Mediterranean climate with high light intensity, long hours of sunshine, low relative humidity and no frosts.

Eastern Australian species grow best in summer rainfall tropical and subtropical coastal areas of Queensland and New South Wales.

Western and eastern species will not usually grow well in the same region.

Varieties

As at 2014, selections for banksia production are based on species, rather than varieties or cultivars of species. The main species of banksia grown for cut flowers in most states of Australia (those with “Mediterranean” climate, winter rainfall, dry summers and low humidity) are Banksia baxteri (bird’s nest banksia), B. coccinea (scarlet banksia), B. hookeriana (Hooker’s banksia) and B. prionotes (acorn banksia). The main species under production in coastal New South Wales and Queensland is B. plagiocarpa (Hinchinbrook banksia). Species native to Western Australia have not been widely accepted for production in other states as they are more susceptible to phytophthora root rot. It is thought that western species will not thrive on the east coast any further north than Sale, Victoria.

Several Dryandra species grown for their cut flowers have recently been reclassified as Banksia species (see list below).

As at 2014, the following species of banksia were used for cut flower production, with a wide variety of flower colours being produced (as indicated after the species name):

• B. attenuata lime green
• B. baxteri greenish yellow
• B. burdettii apricot/orange
• B. coccinea red/grey, yellow/grey
• B. ericifolia dark orange/rusty brown Eastern species
• B. formosa (was D. formosa) orange/bronze, orange/gold
• B. hookeriana creamy pink to peach changing to golden orange as the flower matures
• B. menziesii deep burgundy-red to chocolate-brown, orange, pinks, apricot, bronze, yellow
• B. occidentalis red
• B. plagiocarpa metallic grey/green, bluish grey, yellowish Eastern species
• B. praemorsa yellow/burgundy, red
• B. prionotes cream, orange
• B. robur bluish/green, yellow/green Eastern species
• B. heliantha (was D. quercifolia) rusty orange/yellow, yellow

There are specialist Proteaceae nurseries in most states that provide the best sources of the latest banksia selections.

Irrigated agriculture and horticulture enterprises generally have compatible infrastructure to adapt to growing banksias. Infrastructure and equipment for planting and crop management include machinery for site preparation, tractors for mowing and towing flower trailers, fertiliser spreaders, pesticide application equipment and irrigation infrastructure and equipment.

Robust secateurs, loping jaws and chainsaws may be required for some pruning operations. Some growers have invested in pneumatic secateurs to ease wrist strain. There is growing interest in mechanical methods of pruning in conjunction with hedgerow harvesting.

Banksias can be picked from their third year of establishment onwards and have an economically viable life of around 10 years. They are picked by hand using secateurs, and are best picked in the cool of the morning. The correct stage to harvest varies between none to 20% of florets open along a bloom, depending on species and market. Specific detail is provided in the Quality Specifications listed below. Picking at a later stage can result in some of the older florets dying and reducing the fresh look of the flowers. Banksia leaves dry quickly and cannot be readily rehydrated, therefore the stems should be transferred to water as soon as possible after picking and held in the shade.

To retain quality and maximise vase life, remove field heat by placing stems in buckets of post-harvest solution and cooled to 10°C, before processing the flowers, and then the stems are cooled to 2–4°C in forced-air cooling (if boxed and ready for transport) or in a cool room overnight.

Alternatively, stems may be processed (bunched and graded) within an hour of harvest and then cooled to 2–4°C by either forced-air cooling for 20–30 minutes (if boxed) or holding overnight in a cool room (if in buckets). Forced-air cooling of packed flowers is ideal for large volumes of product.

There is a wide range of market opportunities for wildflower growers (including, but not solely, banksia). Markets can be local, regional, national or international. Each has its own range of management requirements.

At the local level, wildflowers can be sold to local florists, farm or roadside stalls, farmers’ markets, restaurants, motels and resorts. Ideally, the farm will be located within an hour’s drive of these customers, and deliveries can be made twice a week. Regular supply and excellent service are critical to maintaining the market.

Individually or in cooperative arrangements, growers may sell to florists that require a year-round supply of a variety of lines. Flowers need to be packed in flower boxes and delivered direct to florists over a large geographical area. Be aware that banksias are a heavy product, so a box may be quite weighty. Setting up an effective and economic transport network is critical, as is keeping in close contact with customers about orders and payments.

If the flowers are produced close to a capital city, there is the opportunity to sell at flower markets, such as the Sydney Flower Market at Flemington or the National Flower Centre at the Melbourne Markets. Growers may sell their product from a stall at the market, engage an agent to sell their product or sell to a wholesaler.

Growing for export requires careful planning, based on thorough market research and an export marketing plan. Some export advisers recommend that growers learn how to sell flowers on the domestic market successfully, before taking on the export market.

The risks associated with banksia production are the same for wildflower production in general. For banksias specifically, additional risks are that the flowerheads may be damaged by bird or insect attack, during development or just before harvest, making them deformed and unsaleable, as the market likes very symmetrical flower heads.

The greatest risk associated with cut flower production is in not researching the enterprise sufficiently before investing and establishing the business. Extensive research should be carried out on what species (and varieties to grow) and into which market/s the flowers will be sold. Equally important to market research, is gaining a clear understanding of the personal attributes needed to be a successful flower grower and to operate a profitable flower-growing business; and a good understanding on capital investment and time to earn returns on investment. Chapters 1 and 2 of Getting Started in Wildflower Growing provide excellent guidelines for working through these considerations.

Once the business is established, many of the risks and challenges of cut flower production are associated with markets and marketing. These include understanding market requirements and volumes; competition from cheaper product available on the export market; unfavourable exchange rates; judging demand and securing orders prior to harvest; and oversupply of product driving down prices so that returns to the grower are less than the cost of production.

While excellent horticultural management will go a long way to achieving consistent flower quality, there are several potential risks (weather, pests and disease) that can only be managed to a limited extent; though good managers will be better prepared to cope with these. Crop damage, especially close to harvest time, can significantly reduce the number of stems suitable for selling and therefore, that season’s income.

The Banksia production manual DAFWA publication 4710 (2007) available for purchase

NSW Department of Environment & Heritage website – for information on licences and regulations for some protected and threatened native flower species

Australian Government Department of Environment – for information on exporting Australian native species

Australian Government Department of Agriculture – for information on exporting agricultural products

Flower Association of Queensland Inc – Queensland industry organisation

Australian Pesticides and Veterinary Medicines Authority – for information on the use of chemicals and pesticides in agriculture