Page 189 - Tài liệu cây cảnh Bonsai4me Bonsai Basics

excess transpiration and water loss on hot summer days.

Feeding Feed fortnightly; high nitrogen fertiliser from start of growth in
Spring until midsummer, balanced feed until late summer followed by low
nitrogen until winter. Occasionally replacement feeds with an acidic fertiliser
such as Miracid are highly recommended, particularly in hard (lime) water areas.
Repotting
Repot in April, do not repot or rootprune too early in the year. Can also be
very successfully repotted during the warmth and humidity of August, however
avoid repotting during very hot days.
Once established in a good quality soil, repot infrequently every 3-5 years.
Never bare-root a Juniper or change more than a third of the soil (or at very most
half) in any one repotting.
An inorganic-clay based soil is essential for Junipers as they are prone to
very poor-health in old, compacted, organic soils. Because Junipers cannot be
bare-rooted or have more than one third of the soil mass changed in one year, it
is essential that a soil with good particle structure is used. Avoid Akadama and
similar low-fired clays that break down after one to two years.

Wiring
The wood of Juniperus is extremely flexible and branches of several
centimetres in diameter remain supple enough to be shaped with ease. Junipers
can be wired at any time of the year including the semi-dormant period of
Winter. Do not create heavy bends in trunks and branches during temperatures
of 0ºC or less.
For a well-defined Juniper bonsai, the entire tree will require 100% wiring at
least once in its lifetime.
The setting time for newly-wired branches depends on the thickness and the
vigour of individual shoots; expect anything from 3 months to a year. The
greater the amount of growth that emerges from a shoot, the quicker it will
thicken and set into its new position. The thicker a branch is, the longer it will
take to set.

Watch for wire suddenly cutting into the bark during the Summer as the
wood will thicken dramatically during this period, however, shallow wire-marks
are not a great problem and will disappear within a few months to a year (again
depending on the strength and vigour of the individual branch).
Pruning As with all conifers, branches should always be left with enough
foliage to support them, never prune so heavily that a branch is almost devoid of
foliage or it will die off.
Junipers grow from early April as temperatures begin to rise at the beginning
of the growing season by producing a full flush of new buds and leaves. This is