The Latest Cultivation Methods for Potted Boxwood

Boxwood is also known as boxwood wood, small-leaved boxwood, common box and so on. It is a shrub or small tree of the genus Buxus in the family Buxaceae. It has a graceful tree form, with small leaves like broad bean petals, thick and glossy, and stays green all year round. In gardens it is often used as hedges, edging for large flower beds, pruned into spheres or other topiary cultivation, accenting rocks or made into bonsai. Let's take a look below at the cultivation methods for potted boxwood!

Growth Habits of Boxwood

Boxwood prefers fertile, loose loam soil. It can adapt to slightly acidic or slightly alkaline soil, and can also grow in calcareous soil. For potted cultivation, well-decomposed garden soil or leaf mold mixed with an appropriate amount of rice husk ash can be used. It is shade-tolerant and light-loving, prefers moisture, and can withstand about one month of continuous rainy weather, but dislikes long-term waterlogging. It is drought-tolerant; as long as the surface soil or potting soil does not dry out completely, there will be no abnormal symptoms. It is heat-tolerant and cold-tolerant, able to withstand summer sun exposure and severe cold of around minus 20 degrees Celsius, but during hot and humid summers it should be given more ventilation and light. It has extremely strong tillering ability, tolerates pruning, and is easy to shape.

Propagation of Boxwood by Seed

1. Sowing method: In early September, choose loose, fertile, well-drained sandy loam as the sowing site. Apply base fertilizer (organic fertilizer) and mix in carbendazim and other insecticides and fungicides. After deep plowing and leveling, make a sowing bed. The sowing rate is 50-60 grams per square meter. Mix the seeds with an appropriate amount of sand, then evenly scatter them on the seedbed, cover with fine soil 1-1.5 mm, and cover with a layer of straw curtain to retain moisture.

2. Post-sowing management: After sowing, the seeds only grow radicles that year without sprouting. To prevent frost damage, before the soil freezes in mid-to-late November, cover the straw curtain with 5-8 cm of soil. In mid-to-late March of the following year, remove the straw curtain and covering soil, and build a plastic arch shed over the seedbed, controlling the temperature at 25-30 degrees C. After about 20 days, the embryos emerge from the soil surface. Thereafter, control the temperature inside the shed between 20-25 degrees C and water appropriately. When the temperature stabilizes around late April, remove the plastic arch shed.

Propagation of Boxwood by Cuttage

1. Seedbed preparation: The cutting seedbed should be selected on a plot with high terrain, deep soil layer, loose soil, and good drainage and irrigation. After clearing grass roots and stones, form raised beds about 1-1.2 m wide. Apply 10% imidacloprid at 1000 times plus 5% mancozeb at 1500 times as a drench to eliminate underground pests and harmful pathogens. After leveling the seedbed, pat it flat with a shovel, pour on 10% decomposed diluted human waste, then spread a layer of sifted burnt mud ash or yellow soil on the bed surface, about 5 cm thick.

2. Cutting selection: For boxwood cuttings, select excellent current-year lignified or semi-lignified branches. The knives and scissors used for cuttings must be sharp. When cutting, for branches that have already grown small side branches at the nodes, cut 0.5 cm above and below the node, then split the stem node into two halves according to the position where the small branches grow, and insert the two branches separately. For branches that have not grown small branches, you must keep 2 nodes, cut the upper end into a flat cut surface 1 cm above the bud, and cut the lower end into a horseshoe shape or flat cut 0.5 cm from the bud.

3. Cutting method: Insert cuttings shallowly rather than deeply. For small branch division cuttings, the flat cut surface faces downward, with a depth of 1 cm into the soil for the mother plant. For large branch cuttings, the depth is 1 cm with the next stem node inserted into the soil. The cutting should be inserted at about a 45-degree angle to the ground. Shallow and angled insertion helps the cuttings root and survive earlier.

4. Post-cutting management: After boxwood cuttings are inserted, a shade shed should be built to reduce transpiration and direct sunlight on the seedbed. When cutting in early spring or late autumn, a plastic film should also be added to prevent winter damage. After cutting, water frequently to keep the seedbed soil moist; it is best if the surface soil of the seedbed does not turn white. Topdressing for cuttings can be done in conjunction with watering, or potassium dihydrogen phosphate plus urea can be sprayed on the leaves. Weeding must be done very carefully, without bumping the cuttings.

Cultivation Methods for Boxwood

1. Potting soil: Boxwood is glossy green all year round, so purple clay pots are suitable, with purple or light yellow pot colors being best. The pot shape depends on the styling form: for cascade style, a deep cylindrical pot is suitable; for slanting or curved trunk style, an oval or rectangular pot is used. For bonsai soil, use decomposed garden soil or leaf mold mixed with an appropriate amount of rice husk ash as the growing medium. Fertile, loose loam with good aeration and water permeability is best. When potting old stumps, it is advisable to keep the original soil.

2. Watering: Boxwood prefers water relatively well, so in watering one should grasp the principle of “better wet than dry”. During the seedling stage, the root system is shallow and sensitive to water, so generally keep the surface soil moist. During the rapid growth period, the plant grows quickly and needs a lot of water, so it should be watered generously, allowing alternating wet and dry conditions, watering thoroughly.

3. Fertilizing: Boxwood needs relatively more phosphorus during the seedling stage, more nitrogen during the peak growing season, and more potassium in autumn when growth stops. After planting, a 0.4% potassium dihydrogen phosphate solution can be sprayed on the leaves; generally spraying potassium dihydrogen phosphate on the leaves three to four times a month is sufficient. For newly transplanted boxwood seedlings, fertilizing should be done promptly in the early stage, but be careful that the fertilizer concentration is not too high, to avoid burning the new roots.

4. Shaping: Boxwood has strong sprouting ability. Before styling, the trunk can be headed back to let new shoots sprout around or below the cut surface, then according to artistic styling requirements, train and bind the branches. Binding with palm fiber in spring is best. It can also be coarsely bound and finely pruned into cloud-layer or steamed-bun shapes, or processed into a natural tree form. The trunk should follow its natural tendency to form a slanting or prostrate style. Boxwood is very tolerant of pruning and has strong sprouting ability; to maintain a beautiful tree shape, it must be regularly processed and shaped.

5. Repotting: During cultivation, boxwood is generally repotted once every 2-3 years. The best time for repotting is before spring sprouting. Along with repotting, cut off some old roots and overly long or dense roots, replace 1/2 of the old soil, and fill with fertile, loose growing medium to promote root development.

6. Pests and diseases: 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 40% omethoate at 1000-2000 times dilution. The main disease is sooty mold, which can cause 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