Harland Boxwood Bonsai Care Guide
Buxus harlandii or Harland Box is an evergreen cultivar in a family of over 70 boxwood species. This shrub, which is often utilized as a hedge or topiary, grows to about four feet tall and four feet wide in its natural habitat. Native to Asia and Europe, boxwood are popular for their suitability as a bonsai.
Harland Box has small, glossy, green leaves – thinner than those of most boxwood species – and a striking light-colored trunk that is beautifully textured for a built-in aged look. The flowers are monoecious – male and female on the same plant – and are unique-looking, tiny yellow blooms that typically blossom in April to May. The leaves of boxwood are extremely toxic to pets.
While they can be grown inside, boxwood should be kept outside in winter in order to experience their dormancy period. They must be protected from frost, however, and Harland Box in particular does not tolerate temperatures below 37 degrees F. Winter temperatures between 46 and 50 degrees are ideal, with protection offered from drying winds. When temperatures go above 64 degrees F the plant should be offered regular misting and feeding should be reduced.
Boxwood are known and loved for their adaptability – they will grow well in full or indirect sunlight. While Buxus harlandii does love the outside air, it should be offered shade in the hottest summer sun to prevent the foliage from burning.
Boxwood has a fibrous, shallow root system that needs to be kept moist and cool. They are thirsty plants but should not sit in saturated soil. The soil should be permitted to dry out a bit between waterings. As with all bonsai, monitor the soil regularly to assess how your local climate is affecting its water needs and adjust accordingly.
Harland Boxwood should be fed slightly less frequently than other boxwoods. Every 20-30 days during the growing season should suffice, using an all-purpose fertilizer. Once during the growing season you can supplement with an application of liquid fertilizer with pulverized organic feed.
Styles – boxwoods have a growing pattern that lends itself well to informal upright and other park tree type styles.
In addition to pinching with the goal of shaping and leaf reduction, these tight-growing leaves need to be thinned out routinely in order to encourage back budding and allow ventilation and sunlight to reach the interior branches so that they don't become bare. Pruning will assist ramification as well but don't get too vigorous with pruning as this is a rather slow-growing species. Allow the first surge of foliage growth in the spring to take place unabated, then use the rest of the year to shape and refine.
Harland Boxwood bark is stunning yet also quite fragile, so wiring must be done with care. Wire newer branches while they are still flexible as older, lignified shoots will snap under pressure. Do not wrap the wire tightly and check it often for signs of cutting into the fragile bark.
Large wounds do not heal as well as smaller ones and may be better utilized as features. The underlying wood of the shrub, however, is very hard and can take jins and other textural features without much fear of lasting damage.
This bonsai may be propagated by way of air-layering, which should be carried out in April. Hardwood cuttings may be taken in late summer to early fall, using a length of at least four inches and giving the new plant a couple of months to take root. Dividing may also be done in spring.
Box should be repotted every other year, ideally in spring. There is a bit of leeway with regard to potting times and so this can be carried out in summer or fall if necessary, just don't repot during a growth spurt or unusually hot weather. The fibrous root system tolerates pruning well – you can prune peripheral outliers and even remove wedges of growth from the ball. It is highly recommended to wire the plant into the pot following repotting. Use an all-purpose bonsai soil with limestone added. Box do not like acid soil. Keep in a shady spot for a few weeks to allow the roots to take hold again.
Insects / Pests & Diseases:
Boxwood bonsai may be affected by mites, scale, leaf miners, nematodes, or red spider mites. Remove scale by hand or by painting with rubbing alcohol. Other pests may be removed by spraying the plant with a mild insecticide or a mixture of a teaspoon of dish liquid in a quart of water.
Box species are resistant to disease but box blight can cause extensive damage and death to the plant. It is a fungus with no known cause or cure. Routine care and observation of your bonsai goes a long way toward preventing any health problems.