Page 188 - Tài liệu cây cảnh Bonsai4me Bonsai Basics

San Jose Juniper or J. chinensis 'San Jose'

A Juniper with blue-green foliage and beautiful red bark, more commonly
found in the United States. The San Jose is reluctant to form uniformly
adult/scale foliage and on occasions enthusiasts will opt to develop with
juvenile/needle foliage only.
Blue-Rug Juniper, Creeping Juniper or J.horizontalis
A very common Juniper variety sold in garden centres and shopping malls
across the world, J. horizontalis has very weak trunks and branches leading to a
naturally horizontal, creeping growth habit. Predominantly mature/scale foliage
in a range of colours from dark green to steel blue (depending on the specific
variety). Trunks are very slow to thicken.
Himalayan Juniper or J. squamata
Very commonly found growing in European gardens and nurseries, J.
squamata carries juvenile/needle foliage only in a wide variety of colours,
depending on the variety. Very vigorous, fast growing and responsive to bonsai
techniques but its appearance suffers from the retention of old needles that
steadfastly remain on the tree after dying and browning off.

Common Juniper/J. Communis
J. communis is the only truly native Juniper in the UK. A needle juniper with
dull-green foliage, the Common Juniper has a terrible reputation for dying
inexplicably 2-3 years after collection however garden centre/nursery specimens
appear to be far more robust.
Bonsai cultivation notes
Position Full sun though Junipers with predominately scale-like foliage
benefit from a little shade from the midday sun. During winter protect during
frosts below -10°C but coniferous trees should not be over wintered in dark
outbuildings unless temperatures are consistently below -10°C, at this point there
is no requirement for light.
Never try to grow Junipers indoors, though they may seem to tolerate indoor
cultivation at first, poor humidity, lack of light and dormancy will eventually kill

them. Do not trust a vendor, seller, book or website that claims Junipers can be
grown successfully indoors. Dead Junipers can continue to display normal
foliage colour for weeks or even months after they have effectively died.
Watering Ensure Junipers growing in poor, compacted organic soils are not
over watered as they suffer root rot easily, foliage should be misted frequently to
help keep pores free of dust enabling them to breathe. In the case of trees that
have been recently repotted or have root problems, misting is essential as
conifers are able to absorb enough water through their leaf surface to maintain
health until the roots are able to support the tree themselves. Misting also avoids