Page 51 - Ebook bonsai for beginner

Specialized Bonsai traders offer everything from young plants, pre-

Bonsai and pre-styled juniper trees up to high-value Bonsai, in various
styles and shapes.
Pests / diseases: If junipers are well cared for and placed in an ideal

position they are quite resistant against pests. It is important though not
to let the foliage pads get too dense, because otherwise pests can settle
in them more easily. During winter the junipers must be kept in a place
with enough light and they must be checked for pests regularly because
pests can even occur in winter. Junipers can sometimes get infested with

spider mites, juniper scale, juniper aphids and juniper needle miners as
well as juniper webworms for example. Customary insecticide / miticide
sprays will help but you should also find the reason why the tree was
prone to infestation.

A big problem is fungal rust. The diverse juniper species and cultivars
have a very different level susceptibility to rust fungus, there are also
some which are regarded as resistant. As a rule of thumb, the blue-green
junipers are more resistant than those with yellowish-green foliage. The

Japanese junipers are also not infested very often.
On the internet you can find files which list many juniper species and
cultivars and their susceptibility / resistance level to rust fungus.

The rust fungus infests the junipers permanently and causes swellings
from which hard, brown galls emerge. In spring, during rainy weather, the

galls produce large, orange, gelatin-like tendrils, full of spores, which
infest the leaves of pear trees (but there are also types of rust fungus
which use hawthorn or crabapples as a second host instead of the pear).

The fungus causes orange spots on the pear leaves. In late summer
brownish proliferations grow from the bottom sides of the leaves which
release spores that infest junipers again.

While the pear trees in most cases are not fatally affected – they are
newly infested each year again and they can even be treated
successfully with a fungicide, an infested juniper normally cannot be
cured. The visibly infested branches die in most cases and the fungus
can emerge on other tree parts. Removing the parts with the swellings
and galls is no guarantee at all that the fungus will not reappear.

Although some people have a different opinion, it is best to immediately
burn up a rust-infested juniper or put it into the garbage instead of your