Cassuarina equisetifolia, also known as Australian pine, whistling pine, or ironwood, is a fast, evergreen tree with needle-like twigs that make a whistling sound in the wind.

Origin

• Native to Australia (mainly northeast Queensland and northeast New South Wales), Southeast Asia ( India, Bangladesh, New Guinea and the Pacific Islands.
• Grows naturally along coastal areas, behind beaches, on sandy dunes, rocky cliffs and sometimes in lower hills; adapted to salty, poor, sandy soils, high winds and tropical/subtropical climates.

Care

• Grows quickly up to 6 meters in height and more with a diameter of up to 1 meter; Fine, hanging, green to grey-green twigs (not true needles, but photosynthetic twigs) in whorls.
• Prefers full sun (at least 6–8 hours of direct light); Tolerates heat, salt spray, reflected heat and strong winds excellently.
• Plant in very well-drained, poor to sandy soil (sandy, salty, calcareous, gravelly, or rocky); pH neutral to slightly alkaline; tolerates poor, nutrient-poor soils thanks to nitrogen-fixing bacteria (Frankia) in root nodules.
• Watering: sparing; extremely drought and salt tolerant; only water during settlement or extreme drought; once established, almost no water is needed; No wet feet
• Winter hardiness: limited (USDA zones 9–11); tolerates light frost up to about -5 to -8 °C for a short time; not resistant to prolonged frost or harsh winters; in colder climates (such as the Netherlands) grow as a container plant and overwinter frost-free (min. 5–10 °C, light spot indoors).
• Fertilization: little to none; nitrogen-fixing, so no additional nitrogen is needed; Avoid phosphorus-rich manure.
• Pruning: minimal; light design possible; The tree tolerates heavy pruning well.

Usage

• Mainly ornamental and utility trees: as windbreaks, dune stabilization, erosion control along the coast and rivers; shade and avenue tree in tropical/subtropical areas.