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Agathis robusta (Queensland Kauri) - A tall upright growing conifer to 80 feet or more in cultivation (150 feet in habitat) with thick, opposite or spirally arranged leathery elliptic leaves that are 3 to 4 inch long and 1 to 2 inches wide. The vertically straight trunk, often with a spiral twist, has light grey-brown bark that flakes off to expose a lighter layer below. This species is monoecious with separate male and female cones on the same tree. The male (pollen) cones are narrow reddish brown and cylindrical, 2 to 3 inches in length and erect when held on the tree but curled slightly when dropped to the ground. The 4 to 6 inch tall rounded seed cones, held erect in the high branches, are initially green and mature to brown when they begin falling apart while they are still held on the tree.
Plant in full sun and give regular to occasional irrigation. It is noted as hardy to Sunset Zone 15 by Elizabeth McClintock in her "Trees of Golden Gate Park" and our tree was not damaged in the freeze of 1990 when temperatures dipped to 18° F. A magnificent large evergreen upright tree for a garden or street planting and in Australia it is sometimes used for interiorscapes.
Agathis robusta is native to areas of subtropical rainforest on the mainland in Queensland and on Fraser Island in Australia, though most large specimens on the mainland have been harvested. The name of the genus comes from the Greek word 'agathos', meaning "good", likely in reference to the quality of the wood. The specific epithet is the Latin word for "strong" or "robust" in reference to the vigorous growth of the tree. The common name most commonly used is an adaption of the Maori name of Kauri for the New Zealand species, Agathis australis - in Australia this plant is called a Dammar Pine.
Agathis robusta first introduced into California in 1865 by James Welch of San Francisco and there are large specimens in the Santa Barbara and the Los Angeles area. Notably are plants at Santa Barbara City College, Ganna Walska Lotusland, Alameda Park in downtown Santa Barbara and the large tree at the Huntington Botanic Gardens that is the listed Big Tree of this species. This Agathis robusta at the Huntington is notable as it is the largest of the species measured in the U.S.A, so is the National Champion on the California Big Tree Registry. Interestingly this tree was moved between 1907 and 1908 and in book The Huntington Botanical Gardens written by longtime garden superintendent William Hertrich it is noted that at the time they moved this tree it was 40 feet tall and even at 5 feet in depth had few side roots so the tap root was cut and seared with a blow torch before transplanting. This tree, now an immense specimen in their rose garden area is often lovingly referred to as the world's largest cutting. We also have a large tree on the grounds of the nursery and our crops have been grown from seed collected from some of the specimen trees in Santa Barbara.
This information about Agathis robusta displayed is based on research conducted in our horticultural library and from reliable online resources. We also will relate observations made about it as it grows in our nursery gardens and other gardens we have visited, as well how the crops have performed in containers in our nursery field. We will also incorporate comments that we receive from others and we welcome hearing from anyone with additional information, particularly if they can share any cultural information that would aid others in growing it.
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