How to Grow a Boxwood Bonsai? A Detailed Guide to Cultivation Key Points

Boxwood is not very difficult to cultivate. Many gardening enthusiasts like to make boxwood into bonsai and grow them at home, which not only beautifies the environment but also helps purify the air. So how should a boxwood bonsai be cultivated? What issues need attention?

Boxwood

I. Watering

Boxwood likes moisture, and bonsai need frequent watering to keep the potting soil moist, but waterlogging must be avoided. During the high-temperature period in summer, water in the morning and evening, and spray water on the leaves.

II. Fertilizing

During the growing period from May to August, apply 2 to 3 times of decomposed dilute cake fertilizer water. Apply base fertilizer once in winter, using rotted manure or dried cake fertilizer crumbs.

III. Pruning

During the growing period, cut off leggy branches, overlapping branches and excess branches that affect the tree shape at any time. Boxwood sprouts

relatively quickly. Generally, after new shoots emerge, cut off the first 1 to 2 nodes at the tip to prevent leggy growth. After boxwood bears fruit, remove it promptly to avoid consuming nutrients and affecting tree vigor.

IV. Repotting

Generally carried out once every 2 to 3 years, preferably before spring sprouting. When repotting, cut off some old roots and overly long or dense roots, replace 1/2 of the old soil, and fill with fertile, loose cultivation soil to promote root development.

V. Pest and Disease Control

The main pests of boxwood are scale insects and boxwood looper caterpillars. Scale insects can be killed by manual brushing, or sprayed with 80% dichlorvos at 1500 times dilution; boxwood loopers can be sprayed with 80% trichlorfon wettable powder, or with 40% omethoate at 1000 to 2000 times dilution. The main disease is sooty mold, which causes leaf drop. The key to prevention and control is to eliminate scale insects, and frequently spray water on the leaves to wash off dust so that the plant grows well.

Shaping and Care Key Points for Large-Leaf Boxwood Bonsai

        Large-leaf boxwood is an evergreen shrub or small tree of the genus Euonymus in the Celastraceae family, also known as Zhengmu or evergreen euonymus. Because its leaves stay green all year round, it is also called "evergreen" or "large-leaf evergreen". Large-leaf boxwood can be shaped into different bonsai forms such as straight-trunk style, slanting-trunk style, curved-trunk style and double-trunk style according to the shape of the stump.
       The branches of young seedlings are soft and can be shaped from a young age. First wrap and bend the main trunk, then the main branches and side branches, and pay attention to promptly cutting off excess branches. Because its leaves are relatively large, small and medium bonsai crowns mostly use an elegant natural shape, while large bonsai use neat round, bun-shaped or triangular crowns. Shaping is mostly carried out during the growing season using the method of "coarse wiring and fine pruning" - first use metal wire to wrap and bend out the basic form, then carefully prune until the shape is formed. Taking advantage of the fact that large-leaf boxwood heals wounds quickly, the trunk can be carved to make it look aged and antique.
       Large-leaf boxwood likes a warm, humid environment with plenty of sunlight, is slightly shade-tolerant and cold-tolerant, and has no strict soil requirements - ordinary garden soil will do. Normally it can be placed outdoors in a ventilated, sunny spot for care, and watering should follow the principle of watering when dry and watering thoroughly. In summer, water frequently to ensure sufficient water supply and avoid dried leaves. When the air is dry, spray water on the plant, which both increases air humidity and washes dust off the leaf surface, making the leaves clean and glossy. Apply dilute alum fertilizer water once a month to provide sufficient nutrients so that the leaves are dark green and shiny, but avoid excessive fertilizer, otherwise the plant will grow leggy and the leaves will become larger, affecting ornamental value. Large-leaf boxwood has strong sprouting ability, so during care it should be frequently pinched back and the growing tips removed to control plant growth and make the leaves denser and smaller. Branches and new buds on the trunk that affect the tree shape should be removed promptly to maintain the beauty of the bonsai. Do not fertilize in winter. When the potting soil is too dry, water appropriately to keep the soil moist and avoid the bonsai dying from dry freezing. It should be noted that large-leaf boxwood bonsai overwintered indoors should not be moved outside too early, because they sprout relatively early; if they encounter a cold snap in spring or a sudden temperature drop, the new buds can easily freeze to death, weakening the plant's growth and in severe cases even causing the plant to die. Repot once every one to two years in spring. In summer and autumn, the plant is prone to pests such as scale insects, stinging caterpillars, bagworms and leaf-rolling moths, and control should be noted. The main disease is powdery mildew. The cultivation environment can be improved by keeping the air circulating and avoiding a stuffy, humid environment. If disease occurs, spray with carbendazim, thiophanate-methyl or zineb at 600 to 700 times dilution for control.

Care of Boxwood Bonsai

 Whether the care of boxwood bonsai is appropriate affects its lifespan. The following are the care key points for boxwood bonsai:

1. Watering

Watering boxwood bonsai differs from the usual plant care principle of "don't water until dry, water thoroughly when you do" - its watering method is more complex. Boxwood itself grows in areas with relatively high humidity, and when transplanted into a pot it cannot adapt, so it should be given plenty of water in time to maintain a moist state. However, the watering method should also be adapted according to the climate. For example, when there is sufficient water in the pot and the temperature is between 10°C and 20°C, the watering method is simply to mist the plant once a day; when the temperature is above 20°C, if the soil surface is dry, water to moisten the soil, then water thoroughly over every corner of the branches and leaves.

2. Light

Although boxwood likes light, it should not be placed in strong direct sunlight, which can easily damage its branches and leaves. Newly dug-up trees should be placed in a shady spot with diffused light for cultivation for a period of time, and then given routine care. After the boxwood has adapted to the new environment, it can be placed outdoors to grow naturally every 10 to 15 days, which gives it stronger vitality.