Buxus Harlandii - Victor Byrdy
Buxus
The Buxus group embraces many forms around the world. The common English Box, Dutch Box, Korean Box, Japanese Box, the Taiwanese Box (Buxus Harlandii) and the Kingsville Box. They share the same needs and requirement when growing and propagation so the information about the Harlandii will apply to all the Buxus species.
Placement
Buxus Harlandii or Boxwood (essentially all Buxus species) should be positioned outside in a sunny or semi-shaded place. In the winter a cold greenhouse is ideal for winter protection. Harlandii has extremely sculptured bark creating a sense of age and beauty. Protect from the very hot sun as it will burn the leaves.
Watering
In summer the boxwood needs a lot of water, but it can withstand short dry periods. Avoid excess soil wetness. As the ideal pH value for the boxwood is 7 to 8, most normal tap water of good quality can be used
Fertilizing
Use solid organic fertilizer every month or a liquid fertilizer every week during the growing season. Buxus Harlandii, which will not be completely dormant in its winter place, should be fertilized once a month in winter.
Pruning and wiring
Trim the new shoots leaving one or two pairs of leaves. If the canopy becomes very dense the leaves should be thinned out in order to let light get in, prevent the inner twigs from dying and encourage back-budding. Harlandii tolerates hard pruning and extensive deadwood sculpturing very well. When the bonsai is wired you must take care not to damage the delicate beige bark. Wire marks will be visible for a long time.
Repotting
Repot the Harlandii every two to five years depending on its age and size. It tolerates heavy root pruning well. The soil mix should have a pH value of 7 to 8. You can add some pumice or lime rock gravel to your normal soil mix.
Propagation
The Harlandii can be propagated from cuttings and air-layering. Best results are achieved in spring.
Pests and diseases
The boxwood can be attacked by fungal diseases (box blight or phytophthora root rot in wet soil, for example), nematodes, scale, boxwood mite, boxwood leaf miner or boxwood psyllid. There are specific pesticides for most pests and diseases and it can be a good idea to ask a professional gardener for help in serious cases. Pesticides based on Neem oil or Bacillus thuringiensis are also effective against boxwood moth caterpillars.
General information about the Buxus Bonsai
In nature the Harlandii often grows with twisted trunks and branches. The flowers are greenish-yellow and attract bees. All plant parts are poisonous. Harlandii s are very robust and can grow even on barren ground, in full sun or shade. Harlandii tolerates constant trimming very well and can bud from old wood, they are very well suited for bonsai. The common boxwood (Buxus sempervirens) tolerates frost but trees planted in containers should be protected from very low temperatures in winter. Buxus Harlandii has smaller and narrower leaves and a furrowed bark. It is not frost hardy.
Begin heavy pruning in the mid spring as new growth appears. Start by removing damaged or diseased branches, or limbs growing criss-cross or out of place. Next, assess your tree, and which branches will need to be trimmed back to maintain the desired shape. Cut just past budding leaf clusters to prevent unsightly blunt edges. As the growing season progresses, thinning the outer canopy can provide more light to sun-starved inner foliage
Common box goes completely dormant in the winter months, meaning it will not need to be fertilized. An evergreen shrub, your Harlandii will retain its leaves all winter. Slight frosts may cause the leaves to yellow or pale, but they’ll bounce back in the spring.
Part of what makes a boxwood bonsai such a wonderful tree is its tolerance for varying levels of light. Like most trees, they enjoy a fair amount of sunlight, particularly during the growing season. But they’ll get by just fine in semi-shade, or indoor spaces with lower light. In fact, during the harshest summer spells, your tree will thank you for a shady afternoon reprieve. (Their sensitive evergreen leaves can burn in direct, scorching sunlight.)