Phnom Penh Boxwood
Golden-edge boxwood is a plant of the genus Euonymus of the Celastraceae family and one of the varieties of big-leaved boxwood. It is an evergreen shrub or small tree with slightly quadrangular branchlets, dense branches and leaves, and a spherical crown. The single leaves are opposite, obovate or elliptical, with blunt-toothed edges, dark green and shiny surface. Cymes are axillary, with long stems and green-white flowers. The capsule is spherical, light red, and the aril is orange.
Golden-edge boxwood is a plant of the genus Euonymus of the Celastraceae family and one of the varieties of big-leaved boxwood. It is an evergreen shrub or small tree with slightly quadrangular branchlets, dense branches and leaves, and a spherical crown. The single leaves are opposite, obovate or elliptical, with blunt-toothed edges, dark green and shiny surface. Cymes are axillary, with long stems and green-white flowers. The capsule is spherical, light red, and the aril is orange.
Morphological characteristics
Golden boxwood is an evergreen shrub or small tree. The old trunk is brown with slight vertical stripes. The branchlets are slightly quadrangular. The branches and leaves are densely grown. The side branches are opposite and smooth. hair. Crown spherical. The single leaves are opposite, obovate or elliptical, 3-6cm long, thick leathery, with blunt-toothed edges, obvious pinnate veins, dark green and shiny surface. Small cymes are born between the leaf axils of the branches, with long stems and green-white flowers. The capsule is spherical and contains light red seeds. The flowering period is from May to June and the fruiting period is from September to October. The leaves are bright green and clean, with yellow and white markings. They are elegant and elegant. They are an ideal hedge and bonsai material. They are suitable for use in courtyards and central flower beds, and can also be used as potted plants for viewing. In artificial cultivation, the plant height is usually controlled at about 1m. The arils are orange-red.
Growth Habits
Like light, slightly tolerant of shade. Strong adaptability and drought tolerance. Likes warmth and tolerates cold. It has strong germination and branching ability and is resistant to pruning. Tolerant of barrenness, but suitable for growing in fertile, moist, slightly acidic soil.
Variety classification
Common varieties are: Phnom Penh Buxus, with golden leaf margins. Silver-edged boxwood has golden spots on its leaves, and is an important foliage tree species.
Geographical distribution
North subtropical deciduous and evergreen broad-leaved mixed forest areas (major cities: Nanjing, Yangzhou, Zhenjiang, Nantong, Changzhou, Wuxi, Suzhou, Hefei, Wuhu, Anqing , Huainan, Xiangyang, Shiyan)
Central subtropical evergreen and deciduous broad-leaved forest areas (major cities: Wuhan, Shashi, Huangshi, Yichang, Nanchang, Jingdezhen, Jiujiang, Ji'an, Jinggangshan, Ganzhou, Shanghai, Changsha, Zhuzhou, Yueyang, Huaihua, Jishou, Changde, Xiangtan, Hengyang, Shaoyang, Guilin, Wenzhou, Jinhua, Ningbo, Chongqing, Chengdu, Dujiangyan, Mianyang, Neijiang, Leshan, Zigong, Panzhihua, Guiyang, Zunyi, Liupanshui, Anshun, Kunming, Dali)
Garden application
Garden construction is inseparable from the use of color. In garden construction, red, yellow, and green shrubs are commonly used to form color blocks to enrich the garden. color composition. Since there are fewer red and yellow plants, red maple is mostly used for red shrubs, golden-leaf ligustrum is used for yellow shrubs, and there are more varieties of green shrubs, including boxwood, tortoiseshell holly, etc.
The golden-leaf privet commonly used in small yellow shrubs has its obvious shortcomings: golden-leaf ligustrum is a deciduous shrub of the genus Ligustrum in the Oleaceae family. It likes light, is slightly shade-tolerant, intolerant to drought, and Cold-resistant and intolerant of infertility, Ligustrum lucidum can show a good golden color in positive environments, but it does not grow well in negative conditions, let alone appear yellow. At this time, it is no different from a green plant and cannot meet the needs of color composition. . In addition, golden-leaf ligustrum will lose its leaves in autumn and winter. When they fall, they will be brown and the color is very inconsistent. We found that golden-leaf boxwood can make up for the shortcomings of golden-leaf privet in some aspects. Boxwood is an evergreen shrub that is shade-tolerant, drought-tolerant, and cold-tolerant. Golden-edged boxwood is yellow all year round in the garden color block and does not lose its leaves, even under negative conditions. The living environment and site conditions of garden plants are very complex. Objectively, the richer the plant varieties, the better. Phnom Penh boxwood adapts to this need and has positive significance for the diversification of yellow plant varieties in the garden color block. It is used in shade, drought and Under cold conditions, golden-leaf ligustrum has irreplaceable advantages. It can complement each other with other small yellow shrubs and meet the need for color blocks in garden construction.
Golden box boxwood is a foliage plant with bright leaves and bright green leaves. It is very resistant to pruning. It is a common hedge tree species in courtyards. It can be planted around doorways or in the center of flower beds. Its variegated leaves are particularly beautiful.
Cutting propagation
1. Lay a sand bed with good water permeability, and disinfect the sand bed with potassium permanganate or carbendazim two days in advance.
2. Prepare alcohol and plant rooting powder, and prepare the solution according to the instructions.
3. When cutting cuttings, do not choose branches that are too young. Those with a high degree of lignification will easily take root and sprout.
4. When pruning, leave the main trunk and cut side branches. After pruning, you should leave at least one "root" of the bud to facilitate the next pruning.
5. Remove the lower leaves of the cuttings, leaving 3 to 4 leaves on the upper parts. After the cuttings are repaired, soak them in rooting water.
6. Use a shovel to draw a trench on the sand bed, put the cuttings 5 to 10 centimeters in, and cover them with soil after placing them. The spacing between rows is 10 to 20 cm.
7. Appropriate temperature and humidity need to be maintained during the cutting process. Watering should be based on temperature and humidity, and the leaves should always be kept moist. Do not over-water, extend the rooting time, and reduce watering appropriately after the seedlings take root.
8. The cuttings will usually take root in about 30 days, and they can also be placed in pots at appropriate times. The nutrient soil for filling the pot can be prepared with sand, soil and peat soil accounting for one-third each to facilitate ventilation and do not fill the pot too full.
Disease and Pest Control
1. Boxwood borer
The larvae spin silk to connect surrounding leaves and twigs to make temporary nests, and then feed in them, causing serious The leaves will be eaten away and the seedlings will die.
Morphological characteristics: Adult body wings are gray-white, with purple-brown broad bands on the front, outer, and rear edges of the forewings. There are two white spots on the purple-brown band on the front edge. The scales are shiny and purple-red. The head of the larva is black, the trunk is yellow-green, the dorsal line, sub-dorsal line and upper valve line are dark green to dark green, and the valve line is orange-yellow.
Occurrence pattern: 2 to 3 generations a year in northern areas. The larvae form thin cocoons in the bracts and survive the winter. The adults lie dormant during the day and emerge at night, and are phototactic.
Prevention and control methods
① Manual killing: During the egg-laying period of adults, combine pruning of seedlings, remove egg masses and buds, and burn them intensively.
②Use black light to trap and kill insects in the adult stage.
③ When the larvae damage is serious, spray 50 times of fenitrothion emulsion 1000 times. Or 4.5 cypermethrin 2000 times solution. Bt emulsion 500 times liquid spray (note: Bt emulsion is strictly prohibited to be used at the same time as fungicides, and the effect is better when sprayed after 4 pm on a cloudy day).
2. Big-leaf boxwood looper
The larvae swarm in the leaves to feed. After eating all the leaves, they eat the cortex of the young branches, causing the death of the entire plant. Overwintering as pupae, adults have poor flying ability and strong phototaxis.
Morphological characteristics of adult insects. Female adults have silvery white wing bases with light gray stripes, ranging in size and irregular arrangement. There are continuous light gray stripes on the outer edges of the forewings, the midline is not aligned, and there is a large spot at the end of the middle chamber. The wing base has a dark yellow, brown, and gray pattern, and the abdomen is golden yellow with 9 rows of black spots. The male moth has 7 rows of stripes on its abdomen. The larvae are all black, with yellow pronotum and 5 nearly square black spots. The valve line and abdominal line are wide and yellow.
Control methods
①Use the phototaxis of adults to trap and kill them with light during the adult stage.
②Spray 50 times of fenitrothion EC or 2000 times of 4.5 cypermethrin during the larval damage period.
③Eradicate egg masses during the spawning period. Turn the soil around the roots in winter to kill overwintering insect pupae.
3. Japanese turtle waxworm
One generation occurs every year, and the fertilized female adults overwinter on the branches.
Morphological characteristics: Female adult, with grayish white or slightly fleshy wax shell, oval shape. The male adult has a dark brown or brown body, with a darker head and thorax. Nymph, the wax shell is oval to elliptical, and the back is slightly raised.
Prevention and control methods
① Quarantine measures and prevention: When purchasing seedlings from other places, plant quarantine procedures must be strictly implemented to prevent the artificial spread of pests.
② Strengthen garden maintenance and management: Through maintenance and management, create environmental conditions that are not suitable for the survival of scale insects.
Implement rotation planting, clear the garden in a timely manner, burn fallen leaves, weeds, diseased and insect-infected branches, etc. to reduce the population base of overwintering pests, apply fertilizers rationally, and enhance plant resistance. Reasonable pruning to make it ventilated and light-transmitting can change the living environment of the species, weaken its fecundity, and reduce harm.
③Pharmaceutical control: When the insect population density is not high, you can use a soft brush dipped in a small amount of dichlorvos and water (1:50 to 100 times solution) to kill them. When nymphs are in full bloom, spray laundry detergent and diesel emulsion. 150 to 200 times neem oil emulsion. 1. Matrine 1000 to 2000 times liquid. Use 2000 to 2500 times the force to kill, spray once every 10 days or so, and spray 3 times in a row.
④ Protect parasitic wasps and other natural enemies.
4. Pink peach aphid
The wingless viviparous female aphids and nymphs cluster on the tips of branches and the backs of young leaves to suck sap and cause damage. There is often white waxy secretion on the damaged leaves. It can easily cause the occurrence of sooty stains. In severe cases, the branches and leaves will turn black, affecting plant growth and ornamental value. About 10 generations occur every year in Tangshan area.
Prevention and control methods protect natural enemies such as ladybugs and large grass ridges.
Pharmaceutical control can be sprayed with 2000 times liquid of 20 Chrysanthemum EC or 2000 to 3000 times imidacloprid powder.
5. Powdery mildew
It damages the leaves of boxwood. The leaves of the infected plants show shrinkage and deformation, which affects the growth. Powdery mildew is mostly distributed on the front of the leaves of boxwood, and rarely grows on the back of the leaves. The single lesions are round, and the white lesions expand and heal irregularly.
Prevention and treatment methods
① Proper pruning to enhance permeability.
② In the early stage of the disease, alternately spray 25% of thiophanate 1300 times, 70 thiophanate methyl 700 times, and 50% antibacterial wettable powder 800 times. If the disease is serious, pruning must be carried out, and the diseased leaves must be cut off and burned together, and then sprayed with pesticides for control.
6. Big-leaf boxwood leaf spot disease
When the damage is serious, the boxwood will fall off its leaves early and form bare branches, affecting the viewing experience and even causing death. The disease occurs on new leaves, producing small yellow spots that then expand into large irregular spots. The edges of the lesions are raised and the brown edges are wider. There is an extending yellow halo outside the raised edge, with a yellowish brown or grayish brown center and densely covered with black dots.
Prevention and control methods
① Select healthy and disease-free seedlings for planting.
② From early June to July, spray 50 times of carbendazim 500 times or 75% of chlorothalonil 500 times or 50% of sterilizing wettable powder 800 to 1000 times for prevention. To reduce the incidence of disease, spray once every 10 to 15 days for 3 consecutive times.
③In winter, fallen leaves should be removed and burned intensively.
7. Stem rot of boxwood
Stem rot is a major disease that boxwood is susceptible to. In severe cases, the whole plant can die. The first and second-year-old branches are the most severely affected. In the early stage, the stems turn brown, the leaves lose green, the young shoots droop, and the leaves do not fall off. In the later stages, the damaged parts of the stems turn black, the cortex shrinks, the endothelial tissue rots, and there are many tiny black bacteria. As the temperature rises, the affected parts develop rapidly, and the bacteria invade the xylem, causing the death of the entire plant.
Cause of disease The pathogen causing yellow field stem rot is a deuteromycete fungus, which usually lives saprophytically in the soil. As the temperature rises, the soil temperature also rises, and the pathogens invade the stems of seedlings and cause damage. The disease is more common especially in high-temperature and low-lying areas.
Prevention and treatment methods
① Strengthen the maintenance and management of seedlings to improve their own disease resistance.
②Using fully decomposed farmyard manure as base fertilizer can reduce the incidence of seedlings.
③ In summer, seedlings should take cooling measures such as building shade sheds, and large seedlings can use methods such as planting ground cover plants or covering the ground with grass to destroy the environmental conditions for the occurrence of pathogens.
④ Cut off diseased branches promptly and burn them intensively.
⑤ When the number of infected seedlings is small, you can use a brush to apply 50 times 50 times carbendazim solution or 50 times 25 times diemulsifiable concentrate (propazolam) on the stems at the early stage of the disease. When the number of diseased seedlings is large or the disease is at its peak, spray 800 to 1000 times 25 of the enemy's strength of demulsible oil or 500 to 600 times of 50 times of antibacterial special powder on the seedlings.
Both methods are performed once every 7 days, 3 to 4 times in a row, to achieve prevention and treatment.