General Information: Boxes are
densely branched shrubs native to Europe and Asia. A hedge steeped in history, box sprigs have been found in the tombs of
Romans. It is widely used as a hedge plant, and is a common topiary subject. Most varieties of box are marked by a distinctive
"foxy" smell which some find distasteful. The box is an important plant commercially, as it is one of the few woods heavier
than water, and is thus used for making woodcuts and precision instruments.
Most boxes are grown as hardy bonsai, but the Harland box has been successfully grown as
an indoor plant. Box is very popular for bonsai due to its tiny leaves and flowers and its tolerence for extensive pruning
and shaping. One note of caution: box leaves are poisonous, and eating even a few can kill a small pet.
Lighting: Box is not particular.
Sun or shade both work well. Buxus harlandii prefers shade or semi-shade, and has an indoor light requirement of only 800
Temperature: Hardiness depends
on variety, but boxwoods need protection from frost and cold winds even when grown in the proper climate. In the summer, box
appreciates fresh air.
Watering: Moderate, but
does not like wet soil. Allow the box to dry somewhat between waterings.
Feeding: Every two weeks
during growth. Harland Box, every 20-30 days. Use a liquid bonsai fertilizer with one application of pulverized organic fertilizer
during active growth. Fertilize with general purpose fertilizer.
Pruning and wiring: Growth
on the dwarf varieties can be very slow. Box can be wired at any time. It is tolerant of radical treatments, such as jin,
shari and being grown root over rock. Fine bonsai material may frequently be pillaged from old hedges. Leaves may turn reddish
brown in winter. Control shape by thinning and by pinching off most of unwanted new growth.
Propagation: By division
in spring, or from hardwood cuttings taken in late summer or autumn. Air-layering is also possible.
Repotting: Every two years.
Spring is the best time, but as box is a broadleaf evergreen, there is more leeway with appropriate times to repot than with
deciduous trees. It can be repotted in summer and autumn if need be, but avoid repotting during very hot weather or during
a growth spurt. Use basic bonsai soil. Box dislikes acid soil, and the use of limestone in the soil mix or adding an occasional
dose of lime to the soil is recommended. Soil must be well drained.
Pests and diseases: Nematodes, mites and leaf
miners, blackfly, greenfly, and red spider mites. Although box is very disease resistant, honey fungus and rust are sometimes
Species useful for bonsai:
- Buxus harlandii: Harland box - A native of Taiwan, the Harland box can grow to 33
feet. Its leaves are thinner than other box species. This box doesn't like cold,and should not be exposed to temperatures
below 37F, but it has been grown successfully as an indoor plant. If the temperature goes above 65F, the Harland box enjoys
a daily misting, and the amount of food should be reduced. During the winter, keep the tree at a temperature below 65F; between
46F and 50F is best.
- Buxus microphylla: Japanese box - Grows to 5 feet, and has evergreen leaves under
1 inch long. It tolerates both sun and shade. All B. microphylla varieties are scentless. It grows best in zones 5-8.
- Buxus microphylla 'Compacta': dwarf boxwood, Kingsville box. Quarterly spray with
Black Leaf 40 mixed with soap.
- Buxus microphylla 'Koreana': Korean boxwood - the most hardy box, it grows in zones
4-8, but expect the foliage to brown in the winter. It is a low, spreading variety, growing to only 3 feet.
- Buxus microphylla 'Morris Midget': Morris Midget boxwood.
- Buxus sempervirens: common box, English box - this box can grow to 25 feet in a mild
climate, and therefore appears as both hedges and small trees. Its evergreen leaves grow to 1 1/2 inches. This box is hardy
in zones 6-8 with some winter protection at the upper end of the range, although there is a cultivar, 'Vardar Valley' which
is hardy to zone 5. This is a long-lived plant, and historic boxes from Colonial days are still alive in Virginia.
- Buxux sinica - A native of China, similar to other small boxes.