Araucaria heterophylla, or Norfolk Island Pine, is a stately tree resembling true pines. Its characteristic whorled branches are horizontal to the main stem, producing tiers of bright green branches with soft awl-shaped needles that are quite distinctive and symmetrical. On Norfolk Island, these trees will reach 150 feet tall. The trees will grow up to 20 feet tall in containers before they become unmanageable. In the greenhouse, we have had several that have reached 18-20 feet in 5-gallon containers. They are widely planted in California and Florida and are hardy in USDA zones 9-12.
Blooming Time: When grown in containers, they will probably never become reproductive and produce cones. Trees planted in the wild will bear 15 to 20 pound (6.8 to 9 Kg) seed cones that may be up to one foot across (30 cm). An interesting characteristic of the mature cones is that they disarticulate, shedding all of their cone scales until only the small cone axis remains. Araucariaceae is regarded as one of the most primitive families of living conifers.
Culture: Araucaria heterophylla needs partial shade to bright interior lighting, with at least 2 hours of full sun per day to keep the foliage color looking its best. In the greenhouse, we use a soil mix consisting of equal parts of peat moss, loam and sand or perlite. The trees are kept moist and watered when the soil mix feels slightly dry to the touch. It is important to drain any excess water from saucers, as this will tend to cause roots to rot. The plants respond very well to humidity. The ideal humidity is around 50%, so misting the trees twice daily usually helps meet this requirement. The trees should be fertilized on a monthly basis during the growing season with a balanced fertilizer diluted to ½ the strength recommended on the label.
Propagation: Araucaria heterophylla is best propagated from seed.
Araucaria heterophylla was featured as Plant of the Week December 19, 2003- January 8, 2004.
Guide to Past Plants-of-the-Week:
Cal's Plant of the Week was provided as a service by the University of Oklahoma Department of Microbiology & Plant Biology and specifically the late Cal Lemke, who used to be OU's botany greenhouse grower and an avid gardener at home as well. If the above links don't work, then try the overview site. You may also like to look at the thumbnail index. ©1998-2012 All rights reserved.