Create a lush boxwood bonsai with simple care steps. Find expert tips on shaping, watering, and keeping your tiny tree healthy year-round!
Evergreen and long-lasting, boxwood plants have been used for hedges and topiary for a long time. There are over 70 types of boxwood, but the most common for bonsai are the European boxwood (Buxus sempervirens) and the Chinese boxwood (Buxus harlandii).
Types of Boxwood Bonsai
There are over 70 types of boxwood trees in the world, but the Chinese and European boxwood are the most popular for bonsai. While they have some similarities, knowing their differences helps you care for them properly.
European Common Boxwood (Buxus sempervirens)
European boxwood is a popular shrub in England and other parts of Europe. It grows quickly and is easy to shape. This type of boxwood does best outdoors and can handle frost. But if the temperature drops below freezing, it’s best to move it to a cool place for the winter.
In winter, common boxwood goes dormant, so it doesn’t need fertilizer. Since it’s an evergreen, it keeps its leaves all year. Cold weather may cause the leaves to turn yellow or pale, but they will recover in spring.
Chinese Boxwood (Buxus harlandii)
Chinese boxwood is strong but more delicate than European boxwood. It can grow indoors but prefers to be outside in warm weather. However, it should never stay outside in winter. Instead, keep it in a cool room at about 50°F. Unlike European boxwood, it doesn’t fully rest in winter, so it needs fertilizer once a month to stay healthy.
Propagation
You can grow new boxwood plants from cuttings or air-layering. Spring is the best time for this.
Requirements for Growing Boxwood Bonsai
Position
Common boxwood should be kept outside in a sunny or partly shaded spot. In winter, a cold greenhouse is best for protection.
Chinese boxwood can stay indoors but likes to be outside in the summer. In winter, move it to a cool room with temperatures around 50°F (10°C) and plenty of light
Watering
In summer, boxwood needs plenty of water but can handle short dry spells. Avoid making the soil too wet. It grows best in soil with a pH of 7 to 8, so regular good-quality tap water is usually fine.
Fertilizing
Use a solid organic fertilizer once a month or a liquid fertilizer every week while the plant is growing. Don’t fertilize common boxwood in winter when it’s dormant. Chinese boxwood, which doesn’t go fully dormant indoors, should be fertilized once a month in winter.
Pruning and wiring
Trim new shoots, leaving one or two pairs of leaves. If the canopy gets too thick, remove some leaves to let light in. This helps keep inner branches alive and encourages new growth. Common boxwood can handle heavy pruning and shaping, even with deadwood. If you use wire, be careful not to damage its delicate beige bark, as wire marks take a long time to fade.
Repotting
Repot boxwood every two to five years, depending on its size and age. It handles root pruning well. Use soil with a pH of 7 to 8, and you can mix in some pumice or lime rock gravel.
Pests and diseases
Boxwood can be affected by fungal diseases like box blight and root rot in wet soil. Pests such as nematodes, scale insects, boxwood mites, leafminers, and psyllids can also cause problems. There are special pesticides for most of these issues, and if the problem is serious, it’s best to ask a professional gardener for help.
Recently, the boxwood moth has become a big problem in Europe. Its green caterpillars can quickly strip a boxwood of its leaves. You can remove them by hand from bonsai trees. Pesticides with Neem oil or Bacillus thuringiensis also work well against them.
