|
Diseases Affecting Bonsai: Cedar Rusts |
|
by Nina Shishkoff, Ph.D. and Andy
Walsh, M.S.
On the whole, bonsai are probably the healthiest trees on
Earth. In experienced hands, they are well cared for, provided
with appropriate environmental conditions, and supplied with
adequate amounts of macro-nutrients (NPK) and micro-nutrients.
While such good horticultural practices can avoid most pests
and diseases, there are some diseases that can still strike even
the healthiest of bonsai.
One of these is a trio of fungal diseases, called "Cedar
Rusts", that affects Junipers and members of the Rose family.
These diseases can seriously damage or disfigure a bonsai [ed:
the diseases rarely kill the tree]. With an understanding of
disease epidemiology and some precautions these diseases can
be avoided. This trio of diseases are known as Cedar-Apple Rust,
Cedar-Quince Rust and Cedar-Hawthorn Rust. They are caused by
different species of the fungus genus Gymnosporangium. What is
peculiar about all three is that the fungus lives alternately
in Junipers and then in Rose family members. The three diseases
are similar so only an explanation of Cedar-Apple Rust will be
given. The differences between the three types can be seen in
Table 1. |
|
Read more...
|
|
|
Collecting & Training Crab-Apples |
|
by John Biel

The crab apple of this article was collected for several reasons:
its rootage and trunk line and its flowers. The roots were nicely
placed, although not plentiful, and the trunk had a subtle
movement
to it. These features were determined the year before collecting
when all the apples were in bloom. These desirable bonsai elements
you can judge for yourself from the pictures accompanying this
article.
Finding such material was a real treat because the area in which
these apples were growing was overgrown with knee-high tall grass,
weeds and shrubby trees. Apples, as well as many other trees
that grew in this sort of environment, seemed to end up with
straight trunks until they grew beyond the height of the
surrounding
grasses. That was the case with this apple as well. The trunk
above the first branch, about 8 feet up, was a lot more
interesting,
and had an attractive, ready made branch structure as well.
Considering
the ordeal of collecting this apple, it might have been just
as easy for me to try air layering the top! Anyway, it was decided
that this tree, and a few others that my friends and I had staked
out, were going to get dug. Among the friends in question was
David Rowe, who is now the Editor of the Journal of the American
Bonsai Society. David lived in Ontario then and had discovered
an abandoned growing field of a local nursery. He got permission
for all of us to dig whatever we wanted. He is also the one who
assured us that "digging them would be a piece of cake;
they are all growing in sand. Just bring a shovel." So
arrangements
were made to dig our trees in early spring of 1992. |
|
Read more...
|
|
Eastern White Cedar - Pinching Technique |
|
By Greg Cloyd, with Bruce Baker
At a recent advanced study group
meeting, eastern white cedar, or arborvitae, (Thuja occidentalis)
pruning, foliage plane maintenance, and pinching practices were
discussed.
Thuja occidentalis is a fragrant, evergreen, false cedar of
northern
North America. It is differentiated from its western cousin (Thuja
orientalis) by its smaller size, prominent resin glands, slight
differences in cone morphology, and its un-winged seeds. It grows
as a telephone-pole-straight tree of moderate height in its
southern
range. Farther north, in Canada, it is a twisted and contorted,
wind- and snow-tortured, deer-browsed, small tree of bog and
limestone lakeshore. Along the Niagara escarpment and in Quebec
it is a cliff-dwelling ancient dwarf growing less than an inch
in radius per century.
|
|
Read more...
|
|
|
|
|
<< Start < Prev 1 2 3 4 5 6 7 8 9 10 Next > End >>
|
|
Page 9 of 10 |