Kingsville Boxwood Care Sheet

is not the matted fibrous roots of potted azaleas or
junipers, but has similar characteristics if it becomes
root bound. It can also be repotted in the
summer or fall if needed and you live in the South,
though you would want to avoid repotting during
the hottest months. When repotting during other
times of the year, try not to cut roots. Boxwood
prefers well-drained soil mixes and will tolerate
slightly alkaline soil. Use basic low acid bonsai soil
and add an occasional dose of lime to the soil for
optimal health. Add fertilizer and iron to the soil
when repotting. Although not mandatory, Kingsvilles
like a deeper pot.
Design and Styling: The plant does well in many
bonsai styles and is ideal for shohin, mame and
landscape plantings.
Kingsville
Boxwood Care
Sheet
Brought to you by
S & S Bonsai of Colorado Springs, Colorado
(Most of the included information is obtained from several
online sources.)
“Live as if you were to die tomorrow. Learn as if
you were to live forever.”
—Mahatma Gandhi—

The Kingsville Boxwood
(Buxus microphylla x. compacta var. kingsville )
General Information: Kingsville Boxwoods take
their name from the nursery where it was discovered
in Maryland in 1912. However it was not released
to the public until 1937. This is interesting
since most bonsai websites called it Japanese
Kingsville Boxwood and it originated here in the
USA. Seems that sellers feel that we need to think
that all our bonsai originate in Japan. In all fairness,
boxwood were introduced to the United States in
1652 and were a favorite from Maryland to North
Carolina. There are about 115 cultivars available
today.
Kingsville Boxwood belongs to the genus Buxus of
the Buxacae family. This family is widely varied to
include both Pachysandra of ground cover fame as
well as the common boxwoods. Boxwoods are evergreen
trees and shrubs with opposite, shortstalked,
undivided leathery leaves. The plant is very
slow growing. The flowers are petal-less. The fruits
are three lobed and when ripe, they explode on
contact. The hardiest boxwoods are the Buxus microphylla,
which includes the Kingsville variety. The
wood is very fine grained and durable. The leaves
are dark green in the warmth of the growing season
and turn lime green or even yellowish in colder
weather. The color returns to green in the spring.
Leaves that grow old and turn yellow must be removed.
This boxwood is unique among boxwoods for its
scentless evergreen leaves that are less than 1 inch
long. Kingsville Dwarf Boxwood is the most sought
after member of the "Buxus" family. It features
dark green, tiny leathery leaves, dense growth habits
and rough bark which are all the features that
make it a good bonsai subject. Branches grow horizontally
making it look like a miniature version of a
100 year old shade tree.
One note of caution: box leaves are poisonous,
and eating even a few can kill a small pet.
CARE
Temperature: Zone 5-8. In zones 5 and 6, they will
survive in winter storage. Although this boxwood is
hardy to zone four, they survive better in cool indoor
or greenhouse conditions in the winter. The
ideal indoor temperature is less than 65°F. This is
imperative if you style and work with the roots late
in the growing season. All boxwoods need protection
from frost and cold winds even when grown in
the proper climate. Thus, it is important to either
place in a cold frame with ample root protection,
or bring indoors once weather begins to show signs
of frost. Winter injury can be caused by summer
drought, prolonged rainy periods, and forced late
growth; new growth may be burned back. Avoid
sunny winter exposures.
Lighting: Boxwood Bonsai is not picky about lighting
conditions and easily tolerates both sun and
shade and has an indoor light requirement of only
800 Lux which makes it a great plant for indoor
locations that have lower levels of light. Outdoors
partial shade is beneficial for potted specimens.
Indoors place them in bright light or under artificial
light.
Air: In the summer, your boxwood will enjoy being
brought back outside as it appreciates fresh air,
they need a breeze to prevent inside leaves from
mildewing.
Watering: The boxwood bonsai enjoys moderate
moisture levels, but does not like wet soil. Water
thoroughly and then allow to partially dry inbetween
waterings, but not to the point of dehydration.
Be careful especially in cool conditions. It
responds well to daily misting of the foliage.
Fertilizing: A good organic fertilizer works well in
combination with added iron. You will want to feed
this bonsai every two weeks during growth. Fertilize
May until about October. Then allow a rest period
until late December. When kept indoors, begin
fertilizing after winter solstice.
Pruning / Training: Severe cuts can be made into
fall and in early spring. Spring is the optimal time
for pruning. Keeping the shape is relatively easy
because of the slow growth habit of this tree.
When branches are exposed to the sun, hard
break back easily occurs allowing for the development
of foliage pads. Wiring can be done year
round but be careful as the branches are brittle.
Tolerant of radical treatments, such as jinn, shari
and being grown in root over rock styles. Control
shape by thinning and by pinching off most of unwanted
new growth.
1. Minimize foliage removal as Kingsville grow only
¼” to 1” per year.
2. Use copper wire – it will allow you to “feel” the
movement of the branches and avoid breaking
them.
3. Kingsville form naturally interesting shapes –
use them before you cut.
Insects / Pests: Red spider mites, fungus and rust
may be encountered. Watch for curled or pock
marked leaves. Root rot is also noted as a problem,
usually one branch at a time dies. This can be
associated with nematodes. Leaf miners can also
cause blisters on the leaves, spider mites cause
scratch like marks. Over wintering eggs are laid in
September and October.
Propagation: Propagation by mature cuttings
dipped in rooting hormone in fall works well if
placed in a cool greenhouse. The cuttings are
placed in equal parts- sharp builder’s sand, peat
and perlite in a shaded area. Because of the lateness
of taking these cuttings, watering even in
winter is recommended as is some bottom heating.
Air layering from larger specimens also works
well.
Repotting: Usually repotting is only needed every
other year in the Spring. In group plantings every 4
or 5 years is adequate. Roots can be halved in volume
in the spring. Their root system tends to have
a stringy quality that tolerates root pruning well. It