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Virginia Pine - Pinus virginiana
General information:
This scrubby North American native tree is most often found
growing in the poorest sites and will easily adapt to most soil
conditions, except alkaline soils. Capable of reaching up to
70 feet in height, Virginia Pine is more often seen from 20 to
40 feet in height with a 20 to 35-foot spread. The yellowish-green,
1.5 to 3-inch-long, flexible, evergreen needles are joined by
the numerous, mature, prickly cones. The thin, orange/brown bark
becomes ridged and
furrowed on older trees, and is often seen due to the open branching
habit.
The Virginia pine is in some ways esthetically
similar to the Japanese Black Pine, but has smaller needles and
does not grow as thick a trunk. Both have purplish, flaking bark,
needles in pairs, and small cones that stay on the tree.
Family: Pinaceae
Lighting:
Full Sun. Turn the tree from time to time so that light reaches
all parts of the foliage.
Temperature:
Zones 5 through 8.
Watering:
As with any pine, good drainage is essential. This pine, in its
natural habitat, grows on poor dry soils.
Feeding:
Feed once a month from early spring to autumn using a slow-acting
organic fertilizer, and applying chelated iron twice a year.
If you prefer to feed using chemical fertilizers, feed the tree
once every two weeks with a half-strength solution of a fertilizer
meant for acid-loving plants, such as Miracid. If the foliage
does not maintain a nice dark green color, you may need to treat
with chelated iron to make up for an iron deficiency.
Whichever feeding method you use, do not
feed during the hottest months (July and August in the northern
hemisphere), or if the tree is ailing or has been repotted recently
(2-4 weeks).
Pruning and wiring: Initial pruning and positioning of the roots should
ideally be done at the same time as the first major pruning of
the top of the tree. Subsequent pruning of the branches can be
done when wiring. Wiring is best done in the fall, so that the
branches will have time to become accustomed to their new position
while the tree is dormant. If wiring is done in the spring or
summer, the wire must be checked frequently for signs that it
is cutting into the bark. If this happens, the wire must be removed
and if necessary the branch should be re-wired.
To develop the foliage, shorten the new
shoots (candles) by snapping them off with the fingers just before
the needles start to open up in spring, leaving 1/2 to 1 inch
of shoot. Shorten the candles in two stages. First shorten the
strongest candles and one week later, shorten the weakest candles.
To encourage good ramification, reduce the number of end buds
on each branch to two in the fall. Also in the fall, thin the
needles by removing all downward growing needles and needles
that are too large, removing needles from the strongest shoots
first. Remove the most needles from the apex of the tree, and
remove fewer needles as you work down the tree. This allows light
to reach the lower branches, keeping them strong, and slows the
growth of the apex.
Every other spring, if the tree is healthy,
you can remove all of the new candles. The following fall, buds
will appear where the candles were removed. This serves to greatly
shorten the internodes and increase foliage density.
Spray the foliage with water daily during
the summer.
Propagation:
Seed, layering.
Repotting Repot in spring, before the candles open, or in
late summer, after the heat of summer has passed. These are the
two periods of strongest root growth for pines. The Virginia
pine is fast-growing, so repotting should be relatively frequent,
at least every 2-3 years for young (less than 10 years) trees
and every 3-5 years for older ones. Pines need deep, well drained
soil, so plant in a fairly deep container. Simon and Schuster's
recommends 40% soil, 10% peat, and 50% coarse sand. Rémy
Samson recommends 1 part leaf mould, 1 part loam, and 1 part
coarse sand. Peter Chan recommends 1 part loam, 1 part peat,
and 3 parts coarse sand.
Pines and other conifers grow in association
with a symbiotic fungus which grows in the root ball of the tree.
If this fungus is not present, the tree may die. For this reason,
pines and other conifers should never be bare-rooted, unless
steps are taken to re-introduce the fungus to the repotted plant,
such as making a slurry (thin mud) of the old soil and pouring
it over the newly potted soil.
Some experts feel that it is more important
to be sure that the tree always has a healthy root system with
sufficient feeder roots than to worry about symbiotic fungi.
They feel that trees are more likely to die from having their
root systems reduced too much at once than from not having the
fungus present. Certainly it is good advice in any case to be
sure the tree has sufficient roots.
Pests and diseases: None of significance.
Bibliography:
Jahn (ed.) "The Simon and
Schuster Guide to Bonsai"
Murata's "Four Seasons of Bonsai"
Owen's "Bonsai Identifier"
Resnick's "Bonsai"
Samson's "Creative Art of Bonsai'
Tomlinson's "Complete Book of Bonsai"
USDA Fact Sheet ST-481
Compiled by Sabrina Caine
Edited by Thomas L. Zane
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