Detailed Explanation of Osmanthus Tree Planting Techniques and Cultivation Management Key Points

Osmanthus is an evergreen shrub or small tree of the genus Osmanthus in the family Oleaceae, also known as rock osmanthus, nine-mile fragrance, golden millet, etc. It is an excellent garden tree species that combines greening, beautification and fragrance, with both ornamental and practical value. In ancient Chinese poetry praising flowers, the number of works praising osmanthus is also quite considerable, and it has been deeply loved by Chinese people since ancient times. Now let us take a look at osmanthus tree planting techniques!

Variety Classification of Osmanthus Trees

1. Four Seasons Osmanthus variety: Four Seasons Osmanthus is a clustered shrub with a low tree form, short and dense branches, and a round spherical crown. New leaves are dark red, mature leaves are green or yellow-green. The leaves are elliptical to broadly ovate, with a large angle between the main vein and lateral veins, approaching a perpendicular state. Flower buds are usually solitary or 2-3 stacked together, blooming in batches from September each year to March of the following year, with fragrance inferior to that of silver osmanthus, golden osmanthus and red osmanthus. Common varieties include large-leaf Four Seasons Osmanthus and small-leaf Four Seasons Osmanthus. Varieties that bloom in all four seasons include Yueyuegui, Rixianggui, Large-leaf Fodingzhu, and Serrated-leaf Four Seasons Osmanthus.

2. Red Osmanthus variety group: Red Osmanthus is dioecious, with a round spherical crown, light gray bark that is relatively smooth, and sparse lenticels. Leaves are leathery, long elliptical or elliptical, with a relatively flat leaf surface, revolute leaf margins, entire margins, occasionally sparsely toothed at the apex, broadly cuneate at the base, obtuse or short-pointed at the apex, 8-10 pairs of lateral veins, reticulate veins obvious on both sides, petiole 8-10 mm long. Flower color is orange-red, corolla slightly incurved, fragrance faint, flowering from late September to early October. Varieties include Large-flower Red Osmanthus, Serrated Red Osmanthus, Cinnabar Red Osmanthus, and Broad-leaf Red.

3. Golden Osmanthus variety group: Golden Osmanthus has a round spherical crown, strong tree vigor, upright and very dense branches. Bark is gray, lenticels round or elliptical, spring shoots relatively stout. Leaf color is dark green, leaves elliptical, leaf surface uneven, leaf margins slightly wavy. Flower color is yellow, with strong fragrance, does not set fruit, blooms in autumn, flowers are lemon yellow to pale golden yellow. Varieties include Large-flower Golden Osmanthus, Large-leaf Yellow, Huangchuan Golden Osmanthus, Late Golden Osmanthus, Round-leaf Golden Osmanthus, Xianning Late Osmanthus, Ball Osmanthus, Round-petal Golden Osmanthus, Willow-leaf Su Osmanthus, Jinshi Osmanthus, and Wave-leaf Golden Osmanthus.

4. Silver Osmanthus variety group: Silver Osmanthus has a round spherical crown, spreading large branches, dense branches and leaves, and good growth. Bark is light gray, lenticels numerous and large, shaped like snowflakes, very conspicuous. Leaves are green or dark green, long elliptical or elliptical, relatively broad and thick, with a relatively flat leaf surface. Flowering occurs in early to mid-September, flower color is creamy yellow to lemon yellow, with a rich fragrance, does not set fruit after flowering, blooms in autumn. Varieties include Broad-leaf Seed Silver Osmanthus, Willow-leaf Silver Osmanthus, Hard-leaf Silver Osmanthus, Seed Silver Osmanthus, Jiulong Osmanthus, Early Silver Osmanthus, Late Silver Osmanthus, Baijie, Pure White Silver Osmanthus, and Qingshan Silver Osmanthus.

Planting Environment for Osmanthus Trees

1. Temperature: Osmanthus trees prefer warmth. The average temperature in the planting area is 14-28°C, the average July temperature is 24-28°C, the average January temperature is above 0°C, it can withstand a minimum temperature of -13°C, and the optimal growth temperature is 15-28°C. It can overwinter outdoors in areas south of the Qinling Mountains and the Huai River in China. It is not very cold-resistant, but compared with other evergreen broadleaf tree species, it is still a relatively cold-resistant tree species.

2. Water: Osmanthus trees prefer moisture. Humidity is extremely important for the growth and development of osmanthus, requiring an average annual humidity of 75-85% and annual precipitation of about 1000 mm. Especially during the young stage and when adult trees are flowering, they need more water. If drought occurs, it will affect flowering. Waterlogging must be strictly avoided, but it also has a certain ability to tolerate drought.

3. Light: Osmanthus relatively prefers sunlight and can also tolerate shade. Under full sunlight, its branches and leaves grow luxuriantly and flowering is abundant. In shady places, branches and leaves are sparse and flowers are few. If grown in pots indoors in the north, special attention must be paid to sufficient light to facilitate growth and flower bud formation. Strong sunlight and deep shade are unfavorable to its growth. Generally, 6-8 hours of light per day is required.

4. Soil: Osmanthus does not have very strict soil requirements. Except for alkaline soil, low-lying land, or overly clayey soil with poor drainage, it can generally grow. However, slightly acidic sandy loam with deep soil layers, loose fertility and good drainage is most suitable.

5. Air: Osmanthus has a certain resistance to harmful gases such as chlorine, sulfur dioxide and hydrogen fluoride, and also has a relatively strong ability to absorb and retain dust. It is suitable for planting in ventilated and light-transmitting places. It likes a clean and ventilated environment and is not tolerant of smoke and dust damage. After being harmed, it often cannot bloom.

Osmanthus Tree Propagation Techniques

1. Sowing: Osmanthus fruit usually matures from April to May. When the fruit skin changes from green to purple-black, it can be harvested. Osmanthus seeds have after-ripening, requiring at least half a year of sand storage. After harvesting, sprinkle water and pile them for fermentation, remove the flesh, place in a cool place to let the seeds dry naturally, and store mixed with sand. After sand storage, they can be sown in autumn or spring. Before sowing, prepare the land well and apply sufficient base fertilizer. They can also be sown in indoor seedbeds. When sowing, place the seed hilum sideways to prevent the radicle and young stem from bending, which would affect seedling growth in the future.

2. Grafting: Osmanthus grafting rootstock mostly uses glossy privet, small-leaf privet, small wax, water wax, etc. When mass-propagating seedlings, small-leaf privet is mostly used. Before spring sprouting, cut off the rootstock 5 cm above the ground. Cut 1-2-year-old stout osmanthus branches 10-12 cm long, shave one side of the base into a 2-3 cm cut surface, and shave the opposite side into a small 45-degree bevel. Make a vertical cut about 1/3 of the way on one side of the rootstock, about 2-3 cm deep. Insert the scion into the cut, align the cambium, tie tightly with plastic bags, then bury in soil for cultivation.

3. Cuttings: Osmanthus cuttings are usually taken before spring sprouting using fully developed one-year-old branches, cut into 5-10 cm lengths, remove the lower leaves, keep 2-3 green leaves at the top, insert into river sand or loess seedbeds, with plant-row spacing of 3*20 cm. After insertion, water or spray promptly, and shade, maintaining a temperature of 20-25°C and relative humidity of 85-90%. After 2 months, they can root and be transplanted.

4. Layering: Osmanthus can be divided into low layering and air layering. The low layering method is to select relatively stout 1-2-year-old branches from the lower part of a low-trunk mother tree from spring to early summer, choose easily bendable parts, use a sharp knife to cut or ring-bark, press into a 3-5 cm deep trench, and fix the pressed branch with wooden sticks. The air layering method is to select 1-2-year-old stout branches from the mother tree in spring, cut a ring or ring-bark in the same way as the low layering method, then apply culture medium to the wound, tie tightly above and below with plastic bags, and after rooting in autumn, cut away from the mother plant for maintenance.

Osmanthus Tree Planting Techniques

1. Digging holes: Before lifting osmanthus tree seedlings, first dig the planting holes. The diameter of the holes should be 0.5-0.6 m larger than the soil ball carried by the seedling roots, so that when planting, the soil around the soil ball can be tamped down, making the soil ball closely combine with the hole soil. The depth of the holes should be 0.2-0.3 m larger than the soil ball carried by the seedling. When digging holes, pile topsoil and subsoil separately, so that when filling soil, topsoil is filled first and then subsoil. After digging the holes, it is best to apply base fertilizer. Above the base fertilizer, fill in about 10 cm of soil so that the base fertilizer does not directly contact the soil ball, preventing root burn.

2. Planting: When planting an osmanthus tree, place the seedling in the previously dug planting hole, cut off the grass rope binding the crown, adjust the ornamental side, make the tree body upright, and fill in a small amount of topsoil to fix the soil ball. Then cut the binding material and fill in topsoil. When filled to halfway, use a thick wooden stick to tamp the soil around the soil ball. Then continue filling subsoil. It is advisable to cover soil 0.1-0.2 m higher than the original soil ball. If the plant is relatively tall, wooden stakes are needed to support and fix it when planting. After planting, build a soil ridge around it and water thoroughly promptly, until water no longer seeps down.

Osmanthus Tree Planting Management

1. Fertilizer and water: After transplanting osmanthus trees, if heavy rain causes waterlogging in the nursery, dig trenches to drain water. In drought, water to resist drought. In addition to applying sufficient base fertilizer, apply fertilizer 3 times each year, namely in late March apply 0.1-0.3 kg of quick-acting nitrogen fertilizer per plant to promote height growth and more tender shoots; in July apply 0.1-0.3 kg of quick-acting phosphorus and potassium fertilizer per plant to improve drought resistance; in October apply 2-3 kg of organic fertilizer (such as farmyard manure) per plant to improve cold resistance and prepare for overwintering.

2. Pruning: Osmanthus has strong sprouting ability and the characteristic of naturally forming thickets. It flushes shoots twice each year in spring and autumn. If not pruned and buds removed in time, it is difficult to cultivate tall plants, and it easily forms a phenomenon of dense upper branches and sparse lower branches, strong above and weak below. When pruning, except for short cutting when tree vigor and branch vigor grow poorly, generally thinning is the main method, only appropriately thinning overly dense peripheral branches, and cutting out water sprouts and diseased and pest-infested branches, to improve ventilation and light transmission conditions. Timely remove sprouting branches from the base of the trunk to avoid consuming nutrients within the tree and disrupting the tree shape.

3. Loosening soil: In spring and autumn, cultivate once each in combination with fertilization to improve soil structure. Before overwintering, mound soil around the base once, and whitewash the trunk once, which can enhance cold resistance. Weed 2-3 times each year to prevent weeds from competing with seedlings for water, fertilizer and light.

4. Diseases: Common osmanthus diseases include leaf spot, sooty mold, algal spot, root rot, iron deficiency, etc., and prevention and control should be carried out according to the disease situation. Leaf spot, sooty mold and algal spot can be controlled by spraying 0.5 Bordeaux mixture or 5% carbendazim 500-1000 times solution. For root rot, attention should be paid to keeping the soil loose and breathable, and do not allow waterlogging. If root rot is caused by fungi, irrigate the roots with 200-300 times amobam solution.

5. Pests: Common osmanthus pests include sawflies, whiteflies, mites, long white scale, yellow stinging moth, etc. Sawflies, whiteflies and mites can be killed by spraying 100% dimethoate 1500-3000 times solution. For long white scale, in addition to manual brushing, during the first and second instar nymph stages, spray 400% omethoate 1000 times solution or 40% fenitrothion 500 times solution.

Osmanthus Tree Transplanting Techniques

1. Time: When transplanting large osmanthus trees, season selection is very important. Generally (under normal conditions), the semi-dormant period of healthy trees can be selected. For example, in Jiangnan it can be done from after Mid-Autumn Festival to the end of winter of the following year (from mid-September to around February 15 of the following year, excluding severe freezing weather), because this is exactly its semi-dormant stage and new buds have not yet sprouted, which is beneficial for coordinating various factors within the tree. It can also be done during the plum rain season in Jiangnan, because at this time the tree has completed its first growth peak and has already enriched its internal nutrients, so the survival rate is relatively high.

2. Tree selection: For transplanting osmanthus trees, select osmanthus trees with full tree shape, luxuriant branches and leaves, no pests or diseases, and easy to dig up and hoist.

3. Digging pits: About one week before transplanting, dig the tree pits at the new planting site. The pre-dug tree pit diameter should be about 1 m larger than the packaging diameter of the transplanted tree, and the height should be level with the transplant packaging height. Place the excavated topsoil and lower soil separately, spread the soil out to dry, and at the same time clean out impurities such as bricks and tiles from the soil. Then mix in ferrous sulfate at a 10:1 ratio (soil as 10 parts), which increases soil acidity, disinfects the soil, and also enhances fertility.

4. Pruning: Pruning osmanthus is one of the keys to transplant survival. Because osmanthus has weak sprouting ability, trunk cutting and branch cutting are not advisable. Only osmanthus leaves can be pruned. Use scissors to cut off the leaves, leave the petioles, protect the axillary buds, and retain one third of the original leaf quantity. This can both reduce water evaporation and retain the beauty of the original crown.

5. Lifting seedlings: Hard packaging is best for transplanting osmanthus. Water the osmanthus tree to be transplanted thoroughly one week in advance so that its root system absorbs enough water. This makes it easy to dig into a ball and prevents the soil ball from breaking apart because the soil is too dry. The diameter of the soil ball should be 6 to 8 times the crown diameter at 1 m above ground of the plant, and the height should be 70% of the soil ball diameter. If conditions permit, digging larger is better.

6. Planting: Before planting, backfill the pre-dug tree pit with 10-15 cm of original soil brought back during transport of the osmanthus tree. Because osmanthus trees are not tolerant of flooding, the planting depth of osmanthus should be 10-15 cm higher than the original ground level. First lower the osmanthus tree and place it according to its original growth orientation, then place one plastic pipe in each of the four corners of the tree pit, so as to increase root breathability after the tree pit is filled with soil. Then remove the template in order while backfilling soil to 1/3 of the soil ball height, filling original soil closely around the soil ball, tamping layer by layer to prevent the soil ball from breaking. After the tree pit is completely filled and tamped, build a surrounding bank, install supports, and water thoroughly for the first time.

7. Management: First, water thoroughly again 3-4 days after the first watering. Second, after the water has completely dried, surround the remaining soil around the tree pit at the root area, forming a mound higher in the middle and lower around the edges, so that the osmanthus tree will not be drowned by waterlogging. Third, in the following spring, be sure to water once with spring water. Fourth, at an average temperature of about 20°C, spray the leaves and branches once every half month with a mixture of potassium dihydrogen phosphate and fungicide (carbendazim, etc.). This both applies foliar topdressing to the osmanthus tree and plays a sterilizing role.

Osmanthus Tree Planting Methods and Cultivation Management Techniques

Osmanthus is an evergreen tree of the genus Osmanthus in the family Oleaceae, also called muxi rock osmanthus, golden millet, nine-mile fragrance, etc. It has a cultivation history of more than 2500 years in China, is one of China's ten traditional famous flowers, and is also one of the most precious flowering trees in modern urban greening. It originated in the southwest and central-south regions of China, and is now widely cultivated in all provinces and regions of the Yangtze River Basin, while in North China and Northeast China it is mostly grown in pots. It has a graceful tree posture, luxuriant branches and leaves, verdant green leaves, and remains evergreen through the four seasons. It is especially attractive for its faint and secluded floral fragrance, truly “dominating the three autumns and pressing down all other fragrances”, and has been designated as the city flower by world-famous tourist cities such as Suzhou, Hangzhou and Guilin.

Overview of Osmanthus Cultivation

1. Osmanthus varieties: There are many osmanthus varieties, mainly including golden osmanthus, silver osmanthus, red osmanthus and four seasons osmanthus. Golden osmanthus has a tall tree body, a full round crown, large dark green glossy elliptical leaves, wavy leaf margins, thick leaves, golden yellow flowers, and the strongest fragrance. Silver osmanthus has smaller leaves, elliptical, ovate to obovate, relatively thin, flowers yellow-white or pale yellow, fragrance slightly lighter than golden osmanthus, and flowering about 1 week later than golden osmanthus. Red osmanthus has smaller leaves, lanceolate or elliptical, pointed apex, rough leaf surface, flowers orange-yellow or orange-red, and relatively faint fragrance. Four Seasons Osmanthus has plum-shaped elliptical leaves, relatively thin, flowers yellow or pale yellow, a long flowering period, blooming several times except in severe cold and extreme heat, but mostly in autumn, with faint fragrance and smaller leaves, mostly shrub-like.

2. Osmanthus habits: Osmanthus prefers a warm and humid climate and has a certain cold resistance, but is not tolerant of severe cold. It likes light and also tolerates shade. During the seedling stage, a certain degree of shading is required. It does not have high soil requirements and prefers slightly acidic soil in high, dry terrain rich in humus, especially sandy soil with deep soil layers, fertility, moisture and good drainage. It is not tolerant of arid and barren soil, and avoids saline-alkali soil and waterlogged land. Planting in overly wet land with poor drainage will cause poor growth, root rot, leaf drop, and eventually death of the whole plant.

3. Osmanthus cultivation value: Osmanthus is widely used. It is often planted in gardens, along roadsides, on lawns and in courtyards. It is the best greening tree species for government organs, schools, the military, enterprises and institutions, streets and families. Because it has a certain resistance to harmful gases such as sulfur dioxide and hydrogen fluoride, it is also an excellent flowering tree for greening industrial and mining areas. When paired with mountains, stones, pavilions, terraces, buildings and towers, it appears even more dignified and elegant, pleasing to the eye and delightful to the mood. It is also an excellent material for potted plants. After being made into a bonsai, it can provide tree form, stone flowers and fragrance, truly “three benefits at once”. In addition, osmanthus wood is hard, glossy and beautifully grained, and is a good material for carving. Osmanthus is an important raw material for making osmanthus sugar, osmanthus tea, osmanthus wine and osmanthus cake. The essence extracted from osmanthus is widely used in the food industry and chemical industry. Osmanthus bark can extract dyes and tanning materials, and osmanthus leaves can be used as seasoning. They add a fresh fragrance to food.

Osmanthus Propagation Methods

1. Cuttings and grafting: Osmanthus propagation methods include sowing, cuttings, grafting and layering. In production, cutting and grafting propagation are the most common. Cutting propagation has simple technology, large propagation quantity, fast speed, high survival rate and low cost, and is the most widely adopted and most commonly used propagation method by nursery producers and flower enthusiasts.

① Cutting time: From early March to mid-April, select 1-year-old spring shoots for cuttings. This is the best cutting time. From late June to late August, select semi-mature branches of the current year for heel cuttings, but this has high requirements for temperature and humidity control.

② Cutting collection and treatment: From young and middle-aged trees, select robust, full, pest-free and disease-free branches from the middle-upper part and periphery of the tree body as cuttings. Cut the branches into 10-12 cm lengths, remove the lower leaves, and keep only 3-4 leaves at the top. If conditions permit, soak the cuttings in 50 to 100 ppm GGR6 solution for 0.5-1 hour, which is very beneficial for rooting.

③ Cutting medium preparation: Use slightly acidic soil with looseness, aeration and good water retention as the cutting substrate. Before cutting, disinfect and sterilize the cutting medium with drugs such as carbendazim and quintozene.

④ Post-cutting management: Mainly control temperature and humidity, which is the key to whether cuttings can root and survive. The optimal rooting soil temperature is 25-28°C, and the optimal relative humidity should be maintained above 85%. It can be controlled by shading, plastic arch sheds, sprinkling water, ventilation and other methods. Next, attention should be paid to mold prevention, because high temperature and high humidity easily breed mold. Every week, carbendazim and thiophanate-methyl can be used alternately for spraying and sterilization. Grafting propagation has the advantages of fast seedling formation, strong growth, early flowering and small variation, and is also one of the more commonly used methods.

⑤ Rootstock cultivation: Mostly use 1-2-year-old seedlings of glossy privet, small-leaf privet, small-leaf ash, etc. as rootstock. Among them, grafting osmanthus onto glossy privet has a high survival rate and fast initial growth, but the wound heals poorly, and it is prone to breakage when hit by strong wind or external collision.

2. Grafting propagation: Grafting is carried out around Qingming Festival. The two most commonly used methods in production are the cleft grafting method and the side grafting method. For scions, select fully lignified 1-2-year-old robust, disease-free branches from adult trees, remove leaves and retain petioles. When using the cleft grafting method, the rootstock should be cut off 4-6 cm above the ground before grafting in spring before seedlings sprout. The thickness of the scion should match the thickness of the rootstock. The cut surface of the scion should be smooth. The key to successful cleft grafting lies in aligning the cambium of the rootstock and scion and tying tightly. When using the side grafting method, there is no need to cut off the rootstock; directly insert the scion bud into the rootstock, and cut off the rootstock after successful grafting. No matter which grafting method is used, take the scion and graft it as soon as possible. If obtaining scions from other places, be sure to keep the scion branches fresh. Grafting is best done on sunny and windless days. After grafting, pay attention to checking the survival rate, and do a good job in supplementary grafting, bud removal, rootstock cutting, removal of binding tape, water and fertilizer management, and pest and disease control.

3. Seed propagation: Osmanthus can also be propagated by sowing. However, because some varieties do not set fruit or set little fruit, and because seedlings grown by sowing take a long time to flower, requiring more than 10 years to bloom, with great variation, nursery producers and home flower lovers rarely use this method. Osmanthus seeds mature around May. After seed collection, sowing can be carried out in two periods: first, sow immediately after collection, which can reduce the process of seed storage, and some seeds will germinate and emerge in autumn. Its disadvantage is that overwintering management of seedlings is difficult and they are prone to freezing damage. Second, after seed collection, first store in sand, and sow after selecting seeds from the sand in the following spring. They germinate and emerge in April. The advantages of this method are: seedlings grow fast and seedling-stage management is less difficult. When using sowing to raise seedlings, during the seedling stage pay attention to preventing and controlling seedling damping-off, strengthen water and fertilizer management, thin and supplement seedlings in time, cultivate and weed, and do a good job in shading, cooling, and cold and freeze prevention.

4. Layering propagation: Layering time should be selected before buds sprout in spring. Because osmanthus branches are not easy to bend, ground layering is generally not used, only air layering. When using the air layering method, select 2-3-year-old branches with strong growth potential from superior mother plants, ring-bark a 0.3 cm wide strip of bark on the branch, then apply 100 ppm GGR6 solution or the same dose of naphthalene acetic acid to the ring-barked area, then use plastic film filled with mountain soil, leaf mold, moss, etc. to wrap the wounded part, water thoroughly, and tie and fix the bag opening. Observe frequently and replenish water promptly so that the wrapping material is always in a moist state. After cultivation through summer and autumn, new roots will grow. In the following spring, cut the rooted branch away from the mother body, remove the wrapping material, transplant with soil into a pot, water thoroughly, place in a cool place for maintenance, and after a large number of new shoots sprout, expose to full light.

Cultivation Management

One-year-old osmanthus seedlings raised through sowing, cuttings and other methods are not suitable for immediate use as greening seedlings because of poor drought, cold and barren resistance. They should first be transplanted into the nursery for continued cultivation for 2-5 years, and after growing into medium seedlings, transplanted again. The key points of cultivation management are briefly introduced below:

1. Land preparation: Select slightly acidic (pH value 50-6.5) sandy loam with sufficient light, deep soil layers, rich humus, strong permeability, and convenient drainage and irrigation as the cultivation nursery. In the autumn and winter of the year before transplanting, first fully reclaim the nursery once, and dig holes according to plant-row spacing of 1 m x 1.5 m (after 2 years, when they grow thicker and taller, remove every other plant to change the row-plant spacing to 2 m x 1.5 m), with planting holes of 0.4 m x 0.4 m x 0.4 m. Apply 2-3 kg of decomposed neutral farmyard manure (pig manure, cow dung) and 0.5 kg of phosphate fertilizer per hole as base fertilizer. Mix the base fertilizer evenly with surface loam and fill into the holes. After the fertilizer is eroded and fermented by winter snow and spring rain, it is easily absorbed by the seedlings.

2. Transplanting: Transplanting is best when sap has not yet flowed or has just begun to flow, generally from early February to early March. When taking seedlings, keep as many roots as possible and damage as few roots as possible. After taking seedlings, plant as soon as possible. If seedlings need to be transferred from other places, pay attention to moisture retention to prevent seedling dehydration. After planting, tamp the soil and water thoroughly once so that the seedling root system closely contacts the soil.

3. Water and fertilizer management: After transplanting, if heavy rain causes waterlogging in the nursery, dig trenches to drain water. In drought, water to resist drought. In addition to applying sufficient base fertilizer, apply fertilizer 3 times each year, namely in late March apply 0.1-0.3 kg of quick-acting nitrogen fertilizer per plant to promote height growth and more tender shoots; in July apply 0.1-0.3 kg of quick-acting phosphorus and potassium fertilizer per plant to improve drought resistance; in October apply 2-3 kg of organic fertilizer (such as farmyard manure) per plant to improve cold resistance and prepare for overwintering.

4. Pruning and shaping: Osmanthus has strong sprouting ability and the characteristic of naturally forming thickets. It flushes shoots twice each year in spring and autumn. If not pruned and buds removed in time, it is difficult to cultivate tall plants, and it easily forms a phenomenon of dense upper branches and sparse lower branches, strong above and weak below. When pruning, except for short cutting when tree vigor and branch vigor grow poorly, generally thinning is the main method, only appropriately thinning overly dense peripheral branches, and cutting out water sprouts and diseased and pest-infested branches, to improve ventilation and light transmission conditions. Timely remove sprouting branches from the base of the trunk to avoid consuming nutrients within the tree and disrupting the tree shape.

5. Loosening soil and weeding: In spring and autumn, cultivate once each in combination with fertilization to improve soil structure. Before overwintering, mound soil around the base once, and whitewash the trunk once, which can enhance cold resistance. Weed 2-3 times each year to prevent weeds from competing with seedlings for water, fertilizer and light.

6. Pest and disease control: Osmanthus has relatively few pests and diseases, mainly anthracnose, leaf spot, red spider mite and oyster shell scale, etc., which can be controlled with Bordeaux mixture, lime sulfur mixture, thiram, thiophanate-methyl, dichlorvos, dicofol and other agents.

Key Points for Transplanting Large Osmanthus Trees

1. Transplanting time: Mid-January to early February is best. At this time the tree is in a dormant state, and not long after transplanting its activity becomes stronger, making survival easy. Avoid transplanting in summer.

2. Branch cutting: This serves to reduce nutrient consumption within the tree and water transpiration. The amount of branch cutting is determined by tree age and growth vigor. Old trees of over a hundred years should retain few or no branches because of weak growth vigor. Those with strong growth vigor and younger tree age can retain appropriately more branches. When cutting branches, first remove diseased and pest-infested branches, water sprouts and crossing branches. After that, apply petroleum jelly or Bordeaux mixture to the wounds to avoid pest and disease damage and rain erosion.

3. Root cutting: To improve the survival rate of transplanting large osmanthus trees, cut 1/2 of the roots respectively in spring 1-2 years before transplanting. The cut position should be 2-3 times the trunk diameter away from the trunk, then apply 50 to 100 ppm GGR6 solution or 0.1% indole acetic acid solution to the cut roots, cover with soil and water thoroughly, allowing them to grow new roots.

4. Taking the trunk: Determine the soil ball size for excavation, generally 4-6 times the ground diameter of the trunk. If the ground diameter is too thick to transport, it must not be less than 3 times. While digging, wrap the soil ball with wet straw curtains and grass ropes to prevent it from loosening. Large roots of the tree should be sawed off, and GGR6 and other rooting powders should be applied to the cut surfaces. After digging, wrap and tie firmly with wet straw curtains and grass ropes, with grass ropes tied up to 2.5 m height on the trunk.

5. Transport: During transport, load, place and unload gently. When loading, fix the large tree well and use buffer materials between them to prevent the tree from colliding, so as not to damage the bark or break the soil ball. Pay attention to moisture retention on the way.

6. Planting: One month before planting, first dig the planting hole. The hole specification should be 1.5-2 times the soil ball size, then fill the hole with mycorrhizal soil, and mix in 5-10 kg of decomposed neutral farmyard manure and 2 kg of quick-acting phosphate fertilizer, irrigate and set aside. When planting, lower the large tree gently into the planting hole with a crane, cut open the packaging straw curtain and grass rope with scissors, then backfill with stable soil, tread firm, and water thoroughly.

7. Management and care

① Install fixed supports: Set up a tripod around the main trunk of the large tree to prevent the large tree from shaking due to human and animal collision and strong winds.

② Build a shade shed: After April, build a shade shed on three sides of the large tree (except the northwest side) to prevent direct sunlight from scorching the bark and reduce water transpiration. It can be removed when the weather turns cool in October.

③ Watering: Newly planted large trees have damaged root systems and weak water absorption, so the amount of watering should not be too much, to avoid root mold and rot. But it also should not be too little, otherwise the tree body will lose water and die.

④ Infusion: Infusion can meet the attached body's demand for water and nutrients and can greatly improve the transplant survival rate. Infusion is generally carried out from April to September. Before infusion, first drill 3-5 infusion holes at the base of the large tree from top to bottom at a 45-degree angle using a woodworking drill, deep to the pith. Then prepare the medicinal liquid by dissolving 0.1 g of ABT6 rooting powder and 0.5 g of potassium dihydrogen phosphate per liter of water. Hang the bottle containing the medicinal liquid high up, insert the trunk syringe into the infusion hole, open the infusion switch, and the liquid can be infused into the tree body. After the medicinal liquid is infused, pull out the needle and plug the infusion hole with a cotton ball. When infusion is needed next time, clamp out the cotton ball and infusion can proceed. The number of infusions and the interval time depend on the degree of drought, temperature and the plant's water demand. After the plant has completely passed the dangerous period, seal the infusion holes well with Bordeaux mixture.

Osmanthus Tree Cultivation Techniques