Australian Pine - Casuarina equisetifolia

General information: Long-favored for use in erosion control along beaches, Australian-Pine Tree is now outlawed in many parts of Florida due to its invasive nature, rapid growth rate, and non-native status. It is not a true pine tree and is not related to the pines. A straight, upright tree capable of reaching 70 to 90 feet in height and possessing rough, fissured, dark gray bark, Australian-Pine has what appear to be long, soft, gray/green needles but these "needles" are actually multi-jointed branchlets, the true leaves being rather inconspicuous. These "needles" sway gently in the breeze and give off a distinctive, soft whistle when winds are particularly strong. The insignificant flowers are followed by small, spiny cones, less than one-inch-long.

Discovery of the New World made possible great interchange of trees and other plants between East and West. The Yankee Clippers and afterwards botanical explorers brought back from temperate portions of Asia many trees and plants, now found in most gardens. The subtropical regions of Florida, southern Texas, southern Arizona, and California have obtained a wealth of exotic trees from tropical lands throughout the world. Indeed, some of these exotics have become so successful that they have escaped from cultivation and become naturalized, propagating themselves in waste places, road sides, and woods as if wild.

There are 45 species of the genus Casuarina, pronounced Casuarina (cas-you-a-ry-na), variously, known as Australian pine, beefwood, forest oak, she-oak, horsetail tree, and ironwood. A large evergreen tree resembling conifers, with thin crown of drooping branches and with leaves reduced to scale. Leaves like a horsetail.

Useful as wind breakers, especially near the sea. The most widely know and used species as c. equisetifolia and c. cunninghami. C. equisetifolia, frequently called "horsetail tree" is one of the most rapid growers known, as high as 80 feet in a ten year period. It flourishes in the warmest areas in South Florida, Zone 9, on pine land and along exposed shores, but cannot stand frost. C cunninghami is also cultivated in South Florida, being stronger and denser in growth and is somewhat hardier to cold. The wood is very hard, red, heavy and quite durable. To some its appearance is sad, dull gloomy and depressing.

Unisexual, both sexes being usually on the same tree. Male flowers appear in spikes at branchlets tips, feminine flowers in round heads at the bases of branchlets. The staminate born in spikes and the pistillate in dense heads becoming dry cones in fruit. It fruit are dry cones 1/4 to 1/2 inch in diameter, light brown.

Family: Casuarinaceae

Lighting: Full sun to bright shade. This tree does well indoors and will take air conditioning if in a sunny window and not too cold. Keep out of direct cold air. Does well in a green house. (Editor's note: David Fukomoto of the Fuku-Bonsai Nursery in Hawaii disagrees with growing indoors. A minimum of 1000 foot candles of light would be needed, and while it may live, it will be too weak for training. Full sun is recommended.)

Temperature: Does not tolerated extended freeze. Zones 9B through 11.

Watering: Tolerates dry soil between waterings.

Feeding: No information available.

Pruning and wiring: Good for weeping, slanting or cascade style.

Propagation: Seeds or cuttings of half-ripened wood.

Pests and diseases: Pests: No pests are of major concern.

Diseases: Root rot.

Bibliography:

Simpson, Torrey "Ornamental Gardening in Florida", (1926)
Everett, Thomas H. "Living Trees of the World"
Little, Elbert L. "Fifty Trees from Foreign Lands", Year Book of Agriculture, 1949.
Florida Landscape Plants, Watkins 126
Florida Bonsai:1:31-32, IX:2:48
Sunset Bonsai: pg 85
USDA Fact Sheet ST-129

Compiled by Thomas L. Zane