Plant of the Week
Norfolk Island Pine
Latin: Araucaria heterophylla
Christmas approaches, and stores are bedecked in all
their seasonal splendor and crammed full of merchandise. Plants aren’t left out
of this seasonal onslaught.
A plant that makes a return to prime shelf space every December is the
Norfolk Island pine, the perfect living Christmas tree for apartment dwellers.
From outward appearances there is little to indicate that the small tabletop
specimens adorned with red bows and miniature ornaments is in reality a forest
giant of the South Pacific.
Norfolk Island Pine (Araucaria heterophylla) is one of the relatively
few conifers of the southern hemisphere. It's reportedly capable of attaining
200 feet in height, but in most tropical areas, seldom exceeds half that. As a
landscape tree, it grows ramrod straight with whorled branches arising at right
angles to the main trunk. These swoop down in a graceful sweep creating a
picturesque form for older trees.
The flattened, incurved, awl-shaped needles are light green, quarter-inch
long affairs that sheath the young branches. Because the trees of commerce are
all grown from seed, we see only juvenile foliage. Like more common conifers
such as pines and spruce, the needles are not immortal. As the needles attain a
few years' age they begin to fall off, leaving bare, inner branches.
The Norfolk Island pine is native to a small speck of land by the same name
in the middle of the South Pacific, about 900 miles due east of the eastern
bulge of Australia. The tiny island consists of only 13 square miles. In its
splendid isolation from outside influences, the Norfolk Island pines evolved into a unique race of plants unlike the other dozen
Araucarias scattered across the South Pacific.
Norfolk Island was discovered in 1774 during the second voyage of exploration
by Captain James Cook on behalf of the Royal Navy. On this voyage as captain of
the Resolution, Cook was at sea for just over three years and logged more
than 70,000 miles. At one time the crew went 117 days without seeing land - all
without the benefit of GPS or satellite phones. Cook, who discovered New Zealand
on his first voyage and Antarctica on his second, was to be killed on his third
voyage by natives of the big island of Hawaii in 1779.
Growing Norfolk Island pines is relatively easy so long as they are given a
bright location and uniformly moist conditions. But it must always be remembered
that you're trying to keep a tropical giant small enough to fit in your living
room. At least for a time, plant size can be maintained by suppressing root
growth. Just as the Japanese keep trees small using bonsai techniques, smaller
pots keep the size of Norfolk Island pines down.
Plants grown in 6-inch pots will usually get about 2 feet tall and then stop
growing. If transplanted to an 8-inch pot they will grow another foot and stop
again. You can see where this is headed. By the time the plant is in a 24-inch
pot, the tree is 12 feet tall, and you’ve got a problem. It’s too tall for the
house.
You can stop transplanting to a larger pot anywhere in the progression, but
after a couple years, the tree begins to behave like a loblolly pine grown in
close formation. It drops its lower limbs and looks like a beach umbrella with
only foliage at the top.
At this time, it's time to test for winter hardiness. The winter hardiness
test is simple. Leave your overgrown Norfolk Island pine on the patio and see if
it'll survive an Arkansas winter. Of course it won’t, but you can appease any
feelings of guilt by saying you were doing it in the name of science.
By: Gerald Klingaman, retired
Extension Horticulturist
- Ornamentals
Extension News -
December 5, 2003
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