El NiŅo brought record February rainfall to the Los Angeles area, and late morning on February 23, with our heavy clay soil saturated and soft, a downpour toppled our largest bunya bunya, Araucaria bidwillii. The seventy-foot tree, also called bunya pine or monkey-puzzle tree, grew near the Hilgard edge of the garden and wiped out a twenty-foot section of perimeter fence when it went down. Luckily, nobody was nearby when it fell from grace.
By counting the growth rings of the trunk, garden manager Rand Plewak estimated that the plant was approximately fifty years old. Unfortunately, because accession records were not properly kept during the garden's first thirty years, this can only be a guess.
You probably have seen bunya bunya before. Originating from forests in Queensland, Australia, Araucaria bidwillii is a distinctive evergreen conifer with two types of stiff, relatively broad leaves rather than needles. These leaves are arranged around each branch and very prickly. One drawback of the tree for landscaping purposes is its strategy of shedding numerous branchlets, often covering the ground beneath. More importantly, the plant also drops its massive green cones--on record reaching seventeen pounds! These spine-decorated cones are produced on the ends of branches high in the canopy; hence, they are potential killers of passersby when they land. For that reason, each spring garden staff erected yellow caution tape barriers around the tree's perimeter to warn visitors of potential danger.
This particular specimen was unique because it harbored millions of mealybug destroyers (Cryptolaemus montrouzieri). The predatory white larvae feed on mealybugs; hence, this was for us a biological control. (Did you know that MEMBG does not use pesticides?) Sometimes the ground beneath the tree was covered with white litter from the living larvae.
Garden staff had no warning of stress on this tree, nor was it on our suspect list of potential victims or hazards of El NiŅo. Until the soil is excavated and the stump removed, we cannot determine why it fell over. Other trees have been lost from that same east-facing slope since the mid-1980s, many the likely casualties of improper planting, whereby the original roots were contain-bound and not encouraged to spread laterally. Homeowners, take note!
The dear, departed A. bidwillii is survived by a younger specimen just upslope. The older one now rests in pieces--firewood, of course, for anyone who wants to cart the segments away.