Boxwood Bonsai

By Ruth Morgan

Boxwood bonsai are not the most popular bonsai trees but have excellent potential. There is an abundance of foliage due to the short distance between leaves and it is easy to encourage the development of buds.

The leaves are an excellent size for bonsai and the roots will often exhibit strong surface growth.

There are many species of this evergreen shrub that is found across many continents. The two main boxwood bonsai species are Common Box (Buxus sempervirens) and Japanese Box (Buxus microphylla). The latter is much slower growing than Common Box with an eventual height of less than a metre.

Boxwood are outdoor trees that can be kept in sun or part shade. They need protection below -4o C. Some bring boxwood indoors to an unheated well lit area during the winter. If subjected to cold winds and frosts the leaves can discolour but they generally recover well.

Boxwood bark has the advantage of looking mature when still relatively young. The downside is that the trunks take many years to thicken. So if you can gather older boxwood trees from gardens and hedges that will be a great advantage.

Wiring needs to be carried out on the younger flexible branches. As they grow, the shoots become hard and brittle and will snap if wired.

Regular pruning and selective defoliation will pay dividends – reducing the size of the leaves and encouraging the growth of new shoots.

During the growing season feed every 2 weeks. Boxwood bonsai should be repotted every 2 or 3 years during the spring when the buds start to extend.

The informal style works well with boxwood and the multi-trunk forms reflect their natural growth pattern.

Over recent years a serious fungal disease has affected European boxwood. There is no chemical treatment for box blight so it needs to be taken seriously. The symptoms include leaf spots, loss of leaves and branches, black streaks on the bark and fungus growing underneath leaves.  Cutting off infected branches and isolating any trees affected by the fungus are some of the containment measures.

Comments are closed.