Banksia – Known for Their Fruiting “Cones”, Flower Spikes and Flower Heads

Banksia is a group of about 170 species of Australian shrubs and trees in the protea family (Proteaceae). They are famous for their big, brush-like flower spikes and the woody “cones” that form after flowering. Banksias range from low, creeping plants to trees, and they are popular in gardens and as cut flowers.

Scientific Classification & Quick Facts

Common name	Banksia
Scientific name	Banksia
Kingdom	Plantae
Phylum	Tracheophyta
Class	Magnoliopsida
Order	Proteales
Family	Proteaceae
Type	Shrubs and trees (family Proteaceae)
Habitat	Shrubland, forests and rainforests, but not deserts
Native range	Australia
Colours	Buds pink or green; flowers yellow when mature
Flowering season	Autumn, spring and summer
Height	Low shrubs to trees 30 m tall
Special feature	Fruiting ‘cones’ and large flower spikes

Name and Where They Grow

Banksias are named after Sir Joseph Banks, the English naturalist who collected the first specimens in 1770 at Botany Bay, during Captain James Cook’s voyage.

Almost all banksias grow wild only in Australia, and most species are found in the south-west of Western Australia. Just one species also grows naturally in New Guinea and nearby islands. Banksias grow in many habitats, from coastal sand dunes and heathland to open woodland.

What Banksias Look Like

Banksias come in many shapes and sizes. Some grow flat along the ground, many are shrubs, and some become trees about 15 meters (50 feet) tall or more. On exposed, windy coasts, the same species may stay much shorter. Many tree banksias have thick, rough, gray bark and twisted, knobbly trunks.

The leaves are usually tough and leathery. Depending on the species, they can be long and narrow, or have jagged, saw-toothed edges.

Flower Spikes

What looks like one big flower is really a spike made of hundreds, or sometimes thousands, of tiny tube-shaped flowers. They are packed tightly in pairs that spiral around a woody central stem. Depending on the species, spikes can be anywhere from a few centimeters to about 40 cm (16 inches) long, though many are around 10 to 15 cm (4 to 6 inches).

Young flower spikes are often greenish or pale, and as they open they turn yellow, orange, red, pink, cream or bronze. Banksia flowers are full of sweet nectar, which attracts honeyeater birds, insects and small mammals such as the tiny honey possum. These visitors carry pollen from flower to flower.

Fruiting Cones

After the flowers fade, the spike becomes a woody “cone” studded with hard pods called follicles. Each follicle usually holds two seeds. In many species, the follicles stay tightly closed for years and only open after a bushfire, releasing seeds onto ground cleared by the fire. Some banksias can also regrow from a woody swelling at their base after a fire.

How to Grow Banksias at Home

Photo by: Satu Suro

Choosing a Spot

Banksias love sun. Plant them in a sunny position; in very hot climates, a little afternoon shade is fine. They need excellent drainage and do best in light, sandy, slightly acidic soil. Many species grow best in climates similar to their home, with dry summers and mild winters.

Preparing the Soil

• Good drainage is essential. Banksias are prone to a soil disease called root rot (Phytophthora), which spreads in wet, heavy soil.
• In clay or heavy soil, plant on a raised mound or bed about 30 to 60 cm (1 to 2 feet) high, and work in coarse sand or gypsum to improve drainage.
• Banksias grow naturally in poor soils and do not need rich compost or lots of fertilizer.
• They are very sensitive to phosphorus. Only use a small amount of slow-release fertilizer made for native plants, labeled low in phosphorus.
• If leaves turn yellow between the veins, the plant may be short of iron. A dose of iron chelate, used as the label directs, usually helps.

Planting

• Dig a hole about twice as wide as the pot and the same depth.
• Gently take the plant out of its pot, disturbing the roots as little as possible.
• Set it in the hole at the same depth it was growing in the pot, fill in with soil, and firm gently.
• Water deeply to settle the soil around the roots.
• Spread a thin layer of gravel or coarse, low-nutrient mulch around the plant, keeping it away from the stem. Low groundcover plants also make a good living mulch.

Watering

Water young plants regularly, about once a week or whenever the soil is dry a few centimeters down, for their first year or two while their roots spread. Once established, most banksias are very drought-tolerant and need only occasional deep watering in long dry spells. Overwatering is a bigger danger than underwatering.

Growing in Pots

Small and dwarf varieties can be grown in large pots on a sunny porch or balcony. Use a free-draining potting mix made for native plants, and choose a pot with drainage holes, such as a terracotta pot. Let the top of the mix dry out between waterings.

Flowering Season

Different banksias flower at different times, so some are in bloom in almost every season. Many flower in autumn and winter, while others bloom in spring or summer, and a few flower on and off through the year.

Pruning

Light pruning after flowering keeps banksias bushy and tidy. Trim just behind the old flower spikes or cut back the tips of young shoots. Be careful not to cut into old, bare wood, because many banksias cannot grow new shoots from it. Removing old cones is optional; birds and other wildlife may use them.

Banksias as Cut Flowers

Photo by: Gnangarra

Banksias make excellent cut flowers. The sturdy flower spikes last a long time in a vase, and they also dry beautifully, so they are often used in dried arrangements. Their cones are sometimes dyed or used in crafts.

Banksias are grown commercially in Western Australia for the flower trade, and their flowers are sent to countries such as Japan, the United States and those in Europe. Wild banksias are protected in many areas, so flowers should only be picked from plants that are grown or managed for picking.

Banksia FAQs

Related: Photinia Flowers – Derived from the Greek Word Photeinos, Meaning Shiny