Unfortunately Junipers have been given a
bad reputation, although they make some of the most beautiful bonsai
you will have. They are the most common tree used for
“consai” (conning you into thinking it is a bonsai). The
market is full of Junipers stuck in a glazed pot with gravel glued on
top. How many times have you heard someone say, oh I had a Juniper
Bonsai and it died. Chances are it was already dead or dying when you
purchased it, for it can stay green for quite some time after dying.
Also some people only associate bonsai with a Juniper, and having had
one die for them has turned them against bonsai. Of course it
doesn’t help much when they keep the tree on their coffee table
I have had some people that have many
bonsai say they don’t have any luck with Junipers and kill them.
Junipers are very tough plants, but there are a couple of things that
will kill them. One is Spider Mites, they will get them and you have to
be proactive in keeping your trees free of them. Second is over
watering, although a Juniper likes a lot of water through our hot
summers, they do not like to stay wet. Therefore they need to be in a
very well draining soil, this is critical. Sometimes it can be hard to
see that your tree has a problem before it is too late, that is why it
is important to be vigilant on keeping up with their needs.
There are many species, varieties and cultivars of Junipers. We
are only going to discuss a few of the most commonly used. It is
important when choosing a Juniper for bonsai you know the species you
are buying, for some back bud on old wood easier than others, some not
hardly at all. Any of the chinensis varieties tend to back bud well.
Juniperus ‘procumbens nana’ Probably the most
common used for smaller bonsai, although if you can find a large trunk
on one it will make a beautiful specimen.
Juniperus prostrate A quicker growing Juniper that will develop a
large spread, commonly found in nurseries or in your yard, might have a
nice one in your or a neighbors yard worth collecting. With their
spreading habit they can be used for a cascade.
Juniperus chinensis The most commonly used mainly for it’s
ease in back budding. Best varieties are Shimpaku, Parsonii, and San
PRUNING... Junipers can be heavily top pruned and root pruned,
though care must be given when root pruning. Do not saw the root ball
for the delicate feeder roots are located at the ends of the roots and
are easily damaged, instead cut the largest roots out with root pruners
and then comb out the smaller roots.
TRAINING... Wiring is a must when training a Juniper, the more
time you spend wiring the main and secondary branches in its initial
styling and then over the next few years wiring its tertiary branching
the nicer tree you will have. It is best to pinch the growth back
instead of cutting which will cause the tips to brown. Keep up with new
growth for pinching back too far can also cause browning. Keep all
growth growing straight down and in between your branches pinched out.
LIGHT... Junipers prefer full sun, although in the heat of the
summer I sometimes give them a break from the hottest afternoon sun.
FERTILIZE... Junipers are heavy feeders through the growing
season. I use a time release fertilizer and twice monthly feedings of
nitrogen, once foliar and once soil feeding. Periodically use a
balanced fertilizer such as 20-20-20 with acid.
INSECTS... Red Spider Mites, they will get them and when infested
can kill your tree sometimes before you even realize it. They occur
mainly in the wet summer months and in the dry winter months. Once
found you must use a miticide immediately and often to get rid of them.
I use a systemic insecticide to prevent them from appearing. Weekly
spraying using a strong spray from a garden hose is also a good
REPOT... Another way to kill a Juniper is to pot out of season, I
repot my Junipers in February. Young trees may need repotted every two
years, older trees can go 3-4 years. It is best to carefully remove all
or most of the original soil when first potting, you do not want to
create a wet ball around your roots. Use a very well draining soil.
SEASONAL... Junipers are cold hardy and can be left out year