Plant of the Week
Austrian Black Pine
Latin: Pinus nigra
 As the teeth of the chain saw ripped through the trunk of the pine growing
beside my house, I thought of the quote from Aldo Leopold: "Hard times come to
pines as they do to men."
Leopold, who penned A Sand Country Almanac that encapsulates some of
the most distinguished nature writing of the 20th century, said pines will live
to be a century old. But my pine was dead near its 30th birthday - struck down
in its prime by the travails of life.
The tree was an Austrian black pine (Pinus nigra) that had the
potential of reaching 50 feet in height, but mine was only 30 feet tall, a foot
for each year of life. If not crowded by its neighbors, it will hold branches to
the ground and develop the silhouette of a tubby Christmas tree.
The "black" ascribed to the common name is descriptive, for it is a somber
tree. It produces stiff, 4-inch long dark green needles that crowd the stem
producing a bottle-brush arrangement on the branches. The tree is a two-needle
pine. The bark of the main trunk and branches is often gray-brown or sometimes
almost blackish, adding to the somber sentiment.
As the name implies, Austrian black pines are native to Europe. They’re
widely distributed through the mountains of southern Europe and Asia Minor. Over
this wide range of territory, it varies considerably and many botanical variants
have been described. It’s used as a timber species because it’s there, but as
such the boards produced tend to be knotty and of low quality.
In our country, the Austrian pine has served only as an ornamental. As such,
it’s valuable in its youth but decrepit in its old age. The VA hospital in
Fayetteville planted a number of Austrian black pines in the 1930s when the
landscape planting was installed. Forty years later I was called in to advise
the maintenance crew what to do with the wreck these same trees had become.
Like many trees, Austrian black pines are adaptable and easy to grow for the
first 25 years of their life, but once they reach adulthood they begin to
suffer. The most common ailment in the South is a pair of fungal diseases called
diplodia blight and needle-cast disease.
It starts at the base of the plant and affects the oldest needles first,
eventually infecting and then killing those closest to the ground. When the
needles are gone, the blight finishes the job and kills the limbs. Spraying,
while theoretically possible, is impractical once the trees start their slide
into oblivion.
But my pine, and many others in northwest Arkansas, suffered a different end.
As I removed the tree, I discovered the hundreds of exit holes of the ips
beetle, a bark beetle that attacks stressed conifers. My tree - crowded by
mature oaks on two sides - had suffered during the droughts of previous summers.
Two years ago bark beetle scouts cruised the neighborhood when they
discovered, probably due to changes in the phenolic chemistry of my struggling
tree, their next meal. These scouts then produced a congregation pheromone that
attracted a swarm of the tiny brown beetles to lunch at my house.
Will I plant another Austrian pine? Probably not. While this is an attractive
young tree, I prefer the notion of planting trees that will outlive me. In
cooler climates to our north, it will live longer, so there it should be
planted.
By: Gerald Klingaman, retired
Extension Horticulturist
- Ornamentals
Extension News -
January 31, 2003
Back to Archives A - D
|
