I thank my lucky stars that my dad was intensely interested in
trees of all kinds and that his love for these majestic plants
rubbed off on me. Two favorites of the many trees he planted in
our large yard in Kewaunee were an Austrian pine and a Ponderosa
pine. What fun it was to watch those trees grow and put up with
the seasons from the time they were planted as small seedlings
and continuing over a period or around 55 years.
It was around 60 years ago that dad, my three brothers and I spent a
weekend on dad's home farm west of Slovan, WI planting many trees
including pines. One of my spring trips this year will be to
return to that woods at the north end of the farm to see how
those trees are doing.
Another late April or early May
project will be to transplant around a dozen little white pines
that are growing in the young south woods on our property. I
want them closer to the house where the birds can make use of
them for cover and we, in turn, can enjoy both birds and pines.
A large white pine, that we have nicknamed the Skyline Pine and
is growing in our neighbor's field to the south, is the parent of
the pines. The prevailing winds have carried many of the pine
seeds onto our property and they have grown beautifully in with
the quaking aspens that serve as nurse trees, keeping the tiny
pine seedlings shaded and cool until they can fend for
themselves.
In addition to the pines providing many forms
of wildlife excellent cover, good perches and also some food in
the form of seeds, they also add great beauty to the winter
landscape and can serve as efficient windbreaks. Naturally I
favor pines that are native to this region. In this respect I
kid friends by telling them that there are four pines native to
Wisconsin: the jack, red, white, and "porcu"!
Seriously my heart goes out to the white and the red. Even
though jack pines do well here, their features do not make them
very attractive for landscaping.
Exactly what brings about these thick, lush,
rapidly growing formations on a small number of the pines is
unknown to the experts. At least I've never been able to find
the answer. Are they caused by an insect, fungus, virus, or some
mysterious parasite? Who knows? A long time ago one of the
plant pathologists at the Morton Arboretum near Lisle, IL, upon
seeing the many witch's brooms infesting some of the white and
the black spruces at the Ridges Sanctuary, asked me to be on the
lookout f or brooms th at were supporting cones. He and other
plant geneticists were very interested in attempting to propagate
small, thickly growing, so-called "dwarf" trees from
the brooms. Having inspected hundreds of brooms, I have yet to
find one with cones.
The few large pines I know of that
have rather large brooms growing on them appear to be in very
good health from year to year. Spruce trees, on the other hand,
slowly lose vigor and die once they have become infested with
witch's brooms. Study reveals that a small parasitic plant, the
dwarf mistletoe, begins growing on the spruces and eventually may
cause the brooms to form. Gradually most of the water and
nutrients are channeled into the brooms, they become larger and
larger while the rest of the tree loses vigor and eventually
dies, including the brooms.
The dwarf mistletoe,
Arceuthobium pusillum, (ar-coo-THOW-be-um PUE-si-lum) one
of five in the country, is found in the Great Lakes region and
eastward and is common on spruces. The root systems of these
serious pests develop a strong absorption system that can live
off the bark and wood of the host tree for many years. This
devastating action, if started on a twig near the trunk, can grow
into the trunk and become systemic to the point where the tree
will be doomed.
One can view the dwarf mistletoe-witch's
broom-white spruce association in such a way that you begin to
feel that the dwarf mistletoe is actually a beneficial plant in
the vast spruce forests of the world. I'm positive you would be
convinced, after examining many white spruces, that they vary
considerably. The differences in the length, thickness and color
of their needles would surprise you. I've satisfied myself,
having inspected several hundreds of these trees, that the
mistletoe tends to grow better on certain varieties of white
spruces than on others.
Visualizing this phenomenon
occurring in a region for hundreds of years should enable you to
accept the idea that nature is slowly developing a variety of
white spruce for this particular area that will survive very
well. For all we know, these trees may still be going through a
vital adjustment, or evolutionary period, following the retreat
of the last glacier. Don't forget that the place where these
trees are now growing was buried beneath hundreds of feet of ice
less than 10,000 years ago. Nature makes these adjustments and
changes extremely slowly – without mistake! If only we would be
patient and wise enough to follow her examples!
Every once in a while,
when riding around the countryside looking for birds or simply
enjoying the scenery along a quiet country side road as we
patiently wait for spring, we come upon a pine displaying a
bizarre growth or unusual formation. One of the white pines
growing along a back road south of our land sports what I prefer
to call a witch's broom. There are some people who criticize me
for using this term, claiming it is clearly sexist. They choose
to call it simply "brooming" on the pine. Take your
pick.
Also see:
This column appeared in the Door County Advocate on 03/12/1999.
© Copyright 1999 Roy Lukes. All rights reserved.
