Production Methods and Care Management Techniques for Boxwood Bonsai

Boxwood

Aliases: Japanese spurge, Masaki.

Scientific name: Buxus microphylla Sieb. et Zucc

Family and genus: Buxaceae.

Tree species characteristics: Boxwood, also known as seed boxwood and thousand-year dwarf, is an evergreen shrub or small tree of the Buxaceae family. The trunk is grayish-white and smooth, the branches are densely grown, and the branchlets are four-angled. The leaves are opposite, leathery, entire, elliptical or obovate, with a rounded or slightly notched tip, bright green on the surface and yellow-green on the underside. The flowers are clustered in the leaf axils or at the branch tips, opening from April to May, and are yellow-green. The capsule is ovoid.

This genus also includes Korean boxwood, with spoon-shaped or oblanceolate leaves that are dark green and glossy on the surface; and pearl boxwood, an evergreen shrub with glossy leaves. Both of the above have graceful tree forms and are precious species for making bonsai.

Boxwood is produced in the central provinces and regions of China, with wild growth in mountainous areas below 1300 m in elevation. It is widely cultivated along the Yangtze River basin and areas to the south. It likes light and is also fairly shade-tolerant, suitable for growing in fertile, loose, moist sites, and can adapt to acidic, neutral, or slightly alkaline soil. It has strong sprouting ability and tolerates pruning.

Bonsai Production

(1) Material Selection

Seedlings propagated by sowing or cuttings can be transplanted into pots and processed after several years of cultivation. Old stumps can also be selected from mountainous wild areas; after digging them up, prune the overly long roots and dense branches, first grow the material in the open ground for 1-2 years, and then pot and process them.

(2) Potting

① Pot selection: Boxwood is oily green all year round, so purple clay pottery pots are suitable, and pot colors of purple or light yellow are preferable. The pot shape is determined according to the styling form. For the cliff-hanging style, a deep cylindrical pot is suitable; for the slanting style or curved-trunk style, an oval or rectangular pot is used.

② Soil: For bonsai soil, use aged garden soil or leaf mold mixed with an appropriate amount of rice husk ash as the growing medium; it should be fertile and loose, and loam with good aeration and drainage is best. When potting old stumps, it is best to retain some of the original soil.

③ Planting: Boxwood is relatively cold-tolerant and can be planted before spring budding. When planting, prune overly long and overly dense roots, and never let the roots coil up in the pot. Newly planted boxwood should be placed in a semi-shaded place.

(3) Styling

Boxwood has strong sprouting ability. Before styling, the main trunk can be headed back to let new shoots sprout around or below the cut surface, and then according to the requirements of artistic styling, the branches and trunk can be bent and tied; using palm fiber for tying in spring is preferable. Coarse tying with fine pruning can also be used to create cloud-layer or steamed-bun shapes, or to process it into a natural tree form. The main trunk follows its natural tendency and is made into a slanting style or lying style. If boxwood

stump scenery is dotted with ornamental stones, it becomes "boxwood overlooking." Boxwood is very tolerant of pruning and has strong sprouting ability; to maintain a graceful tree shape, it must be processed and reshaped frequently.

Care Management

(1) Watering

Boxwood likes moisture, and bonsai need frequent watering to keep the pot soil moist, but it must not become waterlogged. During high-temperature summer periods, water in the morning and evening, and also spray water on the leaf surfaces.

(2) Fertilizing

During the growing period from May to August, applying 2-3 times of fully decomposed dilute cake fertilizer water is sufficient. In winter, apply 1 basal fertilizer, using decomposed barnyard manure or dried cake fertilizer crumbs, either is acceptable.

(3) Pruning

During the growing period, prune away water sprouts, 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 1-2 nodes at the tips to prevent leggy growth. After boxwood sets fruit, remove it promptly to avoid consuming nutrients and affecting the tree's growth vigor.

(4) Repotting

Generally carried out once every 2-3 years, with the time before spring budding being preferable. Along with repotting, cut off some old roots and overly long or overly dense root systems, replace 1/2 of the old soil, and fill with fertile, loose growing medium to facilitate root development.

(5) Pest and Disease Control

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

Ornamental Value

Boxwood bonsai has a graceful tree form, with leaves as small as broad bean petals, thick and glossy, evergreen in all four seasons, and can be enjoyed all year round. The Yang-style boxwood bonsai, with branches and leaves processed by pruning and tying into a "cloud-layer shape," flat and thin as if shaved, and then dotted with landscape stones, is elegant and beautiful like a painting.

In spring, when boxwood's tender leaves first emerge, the whole tree is tender green and very pleasing to the eye. The ancients wrote poems about boxwood: "A boxwood tree just a foot tall, with thousands of layers of lush branches, leaves deep as emerald in the garden, rooted ancient and crouching like a dragon." This depicts the elegant posture of boxwood, and it is an excellent material for growing bonsai at home.