How to propagate osmanthus saplings? Detailed explanation of care and management key points

Osmanthus has lush leaves and is evergreen, with a long lifespan, blooming in autumn and filling the air with fragrance. It is an ornamental flowering tree and aromatic tree native to China. The areas where osmanthus is concentrated and cultivated in China are mainly the vast tropical and northern subtropical regions north of Lingnan and south of the Qinling Mountains and Huaihe River. Osmanthus trees are quite favored in home cultivation. Below, the editor of Qiannong Network will introduce the cultivation techniques for osmanthus saplings!

Selection of propagation environment for osmanthus saplings

Osmanthus trees prefer a warm and humid climate, tolerate high temperatures but are not very cold-hardy, and are a subtropical tree species. Osmanthus is not very demanding regarding soil. Apart from alkaline soil, low-lying areas, or soil that is too clayey and poorly drained, it can generally grow. However, slightly acidic sandy loam with deep soil layers, loose fertility, and good drainage is more suitable.

Osmanthus is suitable for growing in slightly acidic sandy loam with deep soil layers, good drainage, fertility, and rich humus content. It does not tolerate drought or barrenness. In shallow, compacted, and infertile soil, it grows especially slowly, with sparse branches and leaves, small thin leaves, yellowed leaf color, no flowering or very little flowering, and even periodic dieback of the top, and in severe cases the entire osmanthus plant dies.

Osmanthus likes sunlight but has a certain tolerance for shade. Young trees need some shade, while mature trees require relatively sufficient light to ensure normal growth. According to observation, when one side of a single osmanthus tree's crown is close to a wall, or when the crowns of two osmanthus trees overlap each other, the side close to the wall or the overlapping part of the crown quickly becomes sparse, affecting the overall shape and beauty of the crown. It can be seen that osmanthus is suitable for planting in ventilated and light-transmitting places; osmanthus likes a clean and ventilated environment and does not tolerate smoke and dust damage, and after being damaged it often cannot bloom; it fears waterlogging and standing water. If subjected to waterlogging damage, the root system turns black and rots, the leaves first have scorched leaf tips, then the whole leaf turns yellow and falls off, ultimately leading to the death of the entire plant.

Propagation techniques for osmanthus saplings

Osmanthus propagation and seedling methods include cuttings, layering, grafting, and sowing, with cutting propagation being the main method.

1. Cuttings: The cutting time is generally June-July or September-October, and sandy loam is suitable for the cutting bed. Select semi-mature branches of the current year as cuttings, with terminal branches being best. After cutting, shade promptly, water thoroughly, and strengthen water and fertilizer management. Generally, healing begins about 20 days after cutting, and rooting occurs in 30-40 days. Winter protection measures are needed, and the following year the seedlings can grow to about 30 cm tall.

2. Layering: Layering is divided into air layering (high layering) and ground layering, both of which can be done throughout the year. The air layering method is carried out in early April, while the ground layering method is best done in early April or during the plum rain season. In both layering methods, wounding or ring barking is required, and after 1 year they are separated from the mother plant. For ground layering, the buried depth of the layered branch is about 4-5 cm, and the more bent the buried portion of the branch, the better.

3. Grafting: The grafting propagation time is March-April. The rootstock is mostly small-leaf privet or large-leaf privet. The grafting method is branch grafting, and cleft grafting, split grafting, or approach grafting can all be used. During grafting, shading is required and attention should be paid to moisture retention. For cleft grafting and split grafting, the graft union should be as low as possible, generally cutting off the rootstock at 3 cm above the ground. After binding, mound soil up to the top of the scion so that it may root from the scion part, improving the survival rate.

4. Sowing: Sow in winter or early spring, in drills, with a row spacing of 15-20 cm, sowing 30-40 seeds per meter, with a sowing rate of 8-10 kg per mu, covering with humus soil or burnt soil about 1.5 cm thick, and then covering with grass. Generally, germination begins 40-50 days after sowing and can last up to 50-60 days, with very uneven germination. July-September is the period of vigorous seedling growth, so attention should be paid to topdressing and drought resistance. One-year-old seedlings over 30 cm tall can be released from the nursery.

5. Nursery stock release: After layered seedlings and grafted seedlings have rooted, they can be used for winter afforestation or planted in the nursery to cultivate larger seedlings. When cutting seedlings reach over 30 cm, sowing seedlings reach over 25 cm, and ground diameter reaches over 0.4 cm, they can be released for afforestation or transplanted to the large-seedling cultivation area. When lifting seedlings, the root system should be kept as intact as possible, and they should be planted promptly after lifting. If long-distance transport is required, attention should be paid to moisture retention.

Pest and disease control for osmanthus saplings

1. Scale insects

① Combine with manual pruning to scrape off overwintering pests.

② Before the tree buds, spray 5% anthracene oil emulsion or 5-degree lime sulfur mixture.

③ When scale insects first appear and have not yet formed a waxy layer, spray malathion 1000-fold solution or 25% iminophosphorus emulsifiable concentrate 1000-fold solution, which gives relatively good control results.

2. Red spider mite: It mainly sucks nutrients from osmanthus buds, leaves, and flowers, causing osmanthus buds and flowers to dry up and branches and leaves to turn yellow or wither. You can spray 3-5 Baume lime sulfur mixture before budding, or spray 0.3-0.5 Baume lime sulfur mixture before and after flowering.

3. Leaf spot disease: It mainly harms leaves and in severe cases causes leaf drop. In high temperature and high humidity, this disease develops rapidly. In June-July before flowering, you can use 80% mancozeb wettable powder 0.5 kg mixed with 250-300 kg water for spraying prevention. During the growing season, depending on the condition, spray 1:1:100 Bordeaux mixture.

4. Rot disease: It mostly occurs on the trunk, large branches, and branch crotches. Control measures: strengthen fertilizer and water management, enhance tree vigor, improve drought resistance and disease resistance, and promptly scrape and treat after onset. According to the disease pattern, the focus of inspection and scraping should be in early spring and autumn, and applying 5-degree lime sulfur mixture after scraping gives relatively good results.

Answers to common questions about osmanthus sapling cultivation

Q: For newly planted osmanthus saplings (3 years—5 years), how can the survival rate be made high?

A: It may be that the planting depth is too deep, or the root system is not in full close contact with the soil. If the osmanthus you planted was bare-root planted, you should not only water it, but also cut off some branches and leaves to avoid excessive consumption of nutrients and water. The first watering should be thorough, and the second watering should be about 3 days after the first watering. After that, spray water more and water less, and water about once a week. If it was planted with a soil ball, there should be no problem. After newly planting, the plant generally has an adaptation and recovery period of about two weeks.

Q: What should be done if newly planted osmanthus saplings develop withered leaves due to excessive fertilizing?

A: Generally, transplanted trees should not be fertilized before they survive. You can water the soil more to dilute it, and also spray water on the tree body to retain moisture.

Q: How should newly transplanted osmanthus trees be watered and fertilized?

A: Water appropriately, not too much. Fertilize only after more than a year; newly transplanted ones cannot be fertilized. You can judge by looking at the tree's leaves yourself.

Q: How can osmanthus branches be made to root and then be transplanted?

A: You can use the cutting method. There is a relatively good method! Cut off a somewhat older branch, remove most of the leaves including the main bud, then find some sandy soil and insert the branch into the sandy soil about 4-5 cm. Finally, remember to water frequently to keep the sandy soil moist, and roots can grow in just a few months.

Q: How do you plant osmanthus trees?

A: After planting an osmanthus tree, apply root-setting water three times within 24 hours. The soil and roots must be tight with no air gaps. After that, water once every three to five days to keep the soil moist. Newly planted saplings cannot be given chemical fertilizer or raw farmyard manure. When the daily average temperature is above fifteen degrees, provide shade from sunlight.

Q: How do you distinguish male from female osmanthus trees?

A: Osmanthus is monoecious, but generally osmanthus blooms without setting seed. Only a type called lotus-seed osmanthus blooms and then sets seed, so ordinary people think osmanthus has male and female types.

Q: How do you distinguish osmanthus types?

A: This question should be answered from 2 aspects, namely distinguishing osmanthus types by flower color and by leaves and growth vigor.

1. Simple distinction by flower color

① Golden osmanthus: The flower color ranges from different shades of yellow, the fragrance is strong or extremely strong, the flowers fall off relatively easily, and the flowering period is in autumn. It is the most commonly cultivated type in various places.

② Silver osmanthus: The flowers are yellow-white or pale yellow, the fragrance is relatively light, the flowers are relatively firmly attached, and the flowering period is in autumn. It is generally less cultivated.

③ Dan osmanthus: The flower color is orange-yellow or orange-red, very beautiful, but the fragrance is relatively light, and it blooms in autumn. Although Dan osmanthus has more brilliant flower color, because its fragrance is relatively light, the number cultivated in various places is currently less than that of golden osmanthus.

④ Four-season osmanthus: The flowers are yellow-white or pale yellow, and the fragrance is relatively light, but it blooms several times within a year, and more abundantly in autumn. The plant is relatively short and its growth vigor is relatively weak, often appearing shrubby. Because it blooms many times, although the fragrance is relatively light, it is also quite loved by people and is often potted for indoor display.

2. Distinguishing by leaves and growth vigor

① Golden osmanthus: Leaf margins have serrations.

② Silver osmanthus: Leaf margins are relatively smooth, and the leaves are also relatively large. There is also thorny osmanthus, whose leaves look somewhat like the leaves of Chinese holly.

③ Four-season osmanthus: The leaves are round with almost no tail tip, and the small branches are somewhat loose.

Note: The small branches of golden osmanthus, silver osmanthus, and Dan osmanthus all grow relatively straight and upright. Golden osmanthus has broader leaves than Dan osmanthus. Dan osmanthus has a relatively longer tail tip and more obvious wavy leaf margins. Distinguishing them by flowering period is easier.

Planting methods and cultivation management techniques for osmanthus trees

Osmanthus is an evergreen tree of the genus Osmanthus in the family Oleaceae, also known as muxi, yangui, jinsu, jiulixiang, etc. It has a cultivation history of more than 2,500 years in China and is one of China's ten traditional famous flowers, as well as one of the most precious flowering trees in modern urban greening. It is native to the southwestern and central-southern regions of China and is now widely cultivated in the 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 form, luxuriant branches and leaves, green and verdant foliage, and remains evergreen through the four seasons. It is especially attractive for its subtle floral fragrance, truly “dominating the three autumns and pressing down all 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, Dan osmanthus, and four-season osmanthus, etc. The golden osmanthus tree is tall, with a rounded crown, large dark green glossy leaves that are elliptical, wavy leaf margins, and thick leaves. Its flowers are golden yellow and its fragrance is the strongest. Silver osmanthus leaves are smaller, elliptical, ovate to obovate, and relatively thin. Its flowers are yellow-white or pale yellow, its fragrance is slightly lighter than golden osmanthus, and its flowering period is also 1 week later than golden osmanthus. Dan osmanthus leaves are smaller, lanceolate or elliptical, with pointed tips and rough leaf surfaces. Its flowers are orange-yellow or orange-red and its fragrance is relatively light. Four-season osmanthus leaves are plum-shaped and elliptical, relatively thin. Its flowers are yellow or pale yellow, and its flowering period is long. Apart from severe cold and extreme heat, it blooms several times, but mostly in autumn. Its fragrance is light, its leaves are relatively small, and it is mostly shrubby.

2. Osmanthus habits: Osmanthus prefers a warm and humid climate and has a certain cold resistance, but it is not tolerant of severe cold. It likes light and also tolerates shade, and seedlings need a certain degree of shading. It has low requirements for soil and likes slightly acidic soil on high, dry terrain rich in humus, especially sandy soil with deep soil layers, fertility, moisture, and good drainage. It does not tolerate arid and barren soil, and avoids saline-alkali soil and waterlogged land. When planted in excessively wet land with poor drainage, it will cause poor growth, root rot, leaf drop, and ultimately the death of the entire plant.

3. Osmanthus cultivation value: Osmanthus has relatively wide applications. It is often planted in gardens, on both sides of roads, on lawns, and in courtyards, and is the best greening tree species for government agencies, schools, the military, enterprises and institutions, streets, and homes. 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, rocks, pavilions, terraces, towers, and pavilions, it appears even more dignified and elegant, pleasing to the eye and delightful to the mood. It is also an excellent material for potting, and after being made into a bonsai it can display form, stone flowers, and fragrance, truly “three gains in one.” In addition, osmanthus wood is hard, glossy, and beautifully grained, making it 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, etc. In production, cutting and grafting propagation are the most common. Cutting propagation has simple technology, a large propagation quantity, fast speed, a 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. You can also choose semi-mature branches of the current year from late June to late August for heel cuttings, but this has high requirements for temperature and humidity control.

② Cutting collection and treatment: From young to middle-aged trees, select robust, plump, pest-free branches from the middle-upper and outer parts of the tree body as cuttings. Cut the branches into 10—12 cm lengths, remove the lower leaves, and keep only 3—4 upper leaves. 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, loose, well-aerated soil with good water retention as the cutting substrate. Before cutting, disinfect and sterilize the cutting medium with carbendazim, quintozene, and other chemicals.

④ Post-cutting management: The main task is to 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%. Methods such as shading, plastic arch sheds, sprinkling water, and ventilation can be used for control. Second, 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 quick seedling formation, vigorous growth, early flowering, and small variation, and is also one of the more commonly used methods.

⑤ Rootstock cultivation: Mostly 1—2-year-old seedlings such as privet, small-leaf privet, and small-leaf ash are used as rootstock. Among them, grafting osmanthus onto privet has a high survival rate and fast initial growth, but the wound heals poorly, and it is prone to breaking off when exposed to strong winds or external collisions.

2. Grafting propagation: Grafting is carried out around Qingming Festival. There are two most commonly used methods in production, one is the split grafting method, and the other is the side grafting method. For scions, it is best to select fully lignified 1—2-year-old robust, disease-free branches from adult trees, remove the leaves, and keep the petioles. For the split grafting method, before the seedlings bud in spring, cut the rootstock at 4—6 cm above the ground and then graft. 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 split grafting is that the cambium layers of the rootstock and scion must align, and the binding must be tight. For the side grafting method, it is not necessary to cut off the rootstock; directly insert the scion bud into the rootstock, and cut off the rootstock after the graft succeeds. No matter which grafting method is used, take and graft the scion as much as possible. If the scion is obtained from another place, be sure to maintain its freshness. It is best to choose clear, windless weather for grafting. After grafting, pay attention to checking the survival rate, and do a good job in supplementary grafting, bud wiping, rootstock cutting, removing binding strips, water and fertilizer management, and pest and disease control.

3. Sowing propagation: Osmanthus can also be propagated by sowing. However, because some varieties do not set seed or set few seeds, and because seedlings grown by sowing take a long time to flower, needing more than 10 years to bloom, with large variation, nursery producers and home flower growers rarely use this method. Osmanthus seeds mature around May. After collecting seeds, sowing can be done in two periods: one is to sow immediately after collection, which can reduce the process of seed storage, and by autumn some seeds will germinate and emerge. Its disadvantage is that overwintering management of seedlings is difficult and they are prone to freezing damage. The second is to first store the seeds in sand after collection, then select the seeds from the sand and sow them the following spring. They germinate and emerge in April. The advantages of this method are that seedlings grow quickly and seedling-stage management is less difficult. When using sowing to raise seedlings, attention should be paid during the seedling stage to preventing and controlling seedling damping-off, strengthening water and fertilizer management, timely thinning and filling of seedlings, intertillage and weeding, and doing a good job in shading and cooling as well as cold and freeze protection.

4. Layering propagation: The layering time should be selected before buds sprout in spring. Because osmanthus branches are not easy to bend, ground layering is generally not used, and only air layering is used. When using the air layering method, select a vigorous 2—3-year-old branch on a superior mother plant, 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 to hold mountain soil, leaf mold, moss, etc., wrap the wounded part, water thoroughly, and then tie and fix the bag opening. Frequently observe and replenish water in time 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 from the mother plant, open the wrapping material, move it with soil into a pot, water thoroughly, place it in a cool place for care, and after a large number of new shoots sprout, then expose it to full sunlight.

Cultivation management

One-year-old osmanthus seedlings raised through sowing, cuttings, and other means should not be used immediately as greening seedlings because of their poor drought, cold, and barren resistance. They should first be transplanted into nursery land and continue to be cultivated for 2—5 years, and after they grow into medium seedlings, then transplanted. The key points of cultivation management are briefly introduced as follows:

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 irrigation and drainage as the cultivation nursery land. In the autumn and winter of the year before transplanting, first plow the nursery land completely once, and dig holes according to a plant-row spacing of 1 m x 1.5 m (after 2 years, when they grow thicker and taller, remove every other plant so that the row-plant spacing becomes 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 thoroughly decomposed mild farmyard manure (pig manure, cow dung) and 0.5 kg of phosphate fertilizer as base fertilizer in each hole. Mix the base fertilizer evenly with the surface loam and fill it into the holes. After the fertilizer is eroded and fermented by winter snow and spring rain, it is easily absorbed by the saplings.

2. Transplanting: It is best to transplant when the 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 them as soon as possible. If seedlings need to be transferred from another place, pay attention to moisture retention to prevent dehydration. After planting, press the soil firmly and water thoroughly once so that the seedling root system is in close contact with the soil.

3. Water and fertilizer management: After transplanting, if heavy rain causes water accumulation in the nursery land, dig ditches to drain it. In drought, water to resist it. 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 sends out shoots twice each year in spring and autumn. If not pruned and buds wiped in time, it is difficult to cultivate tall plants, and it easily forms a phenomenon of dense upper branches and sparse lower branches, strong at the top and weak at the bottom. When pruning, apart from shortening branches whose tree vigor and branch vigor are poor, generally thinning is the main method, only appropriately thinning overly dense outer branches and cutting off water sprouts and diseased and pest-infested branches to improve ventilation and light transmission conditions for the plant. Timely wipe off sprouting branches from the base of the trunk to avoid consuming nutrients within the tree and disturbing the tree shape.

5. Loosening soil and weeding: In spring and autumn, cultivate once each in combination with fertilizing to improve soil structure. Before overwintering, mound 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 disease, red spider mite, and oystershell scale, etc., which can be controlled with Bordeaux mixture, lime sulfur mixture, thiram, thiophanate-methyl, dichlorvos, dicofol, and other chemicals.

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 easier. 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 over a hundred years old should have few or no branches left because of weak growth vigor. Those with strong growth vigor and younger tree age can appropriately retain more branches. When cutting branches, first remove diseased and pest-infested branches, water sprouts, and crossing branches. Afterward, 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, in the spring 1—2 years before transplanting, cut 1/2 of the roots respectively. The distance from the cut to the trunk is 2—3 times the trunk diameter. Then apply 50 to 100 ppm GGR6 solution or 0.1% indole acetic acid solution to the cut roots, cover with soil, water thoroughly, and let them grow new roots.

4. Taking the trunk: Determine the size of the soil ball to be dug, generally 4—6 times the ground diameter of the trunk. If the ground diameter is too thick and it is truly difficult to transport, it must not be less than 3 times. While digging, wrap the soil ball with wet straw curtains and straw ropes to prevent it from loosening. Saw off the large roots of the tree and apply GGR6 and other rooting powder to the cut surfaces. After digging, wrap and tie it firmly with wet straw curtains and straw ropes, with the straw rope tied up to 2.5 m high on the trunk.

5. Transport: During transport, load, place, and unload gently. When loading the truck, fix the large tree well and use cushioning materials in between to prevent the tree from colliding and to avoid damaging the bark or breaking the soil ball. Pay attention to moisture retention along the way.

6. Planting: One month before planting, first dig the planting hole. The size of the hole is 1.5—2 times that of the soil ball. Then fill the hole with mycorrhizal soil and mix in 5—10 kg of thoroughly decomposed mild farmyard manure and 2 kg of quick-acting phosphate fertilizer, and irrigate for later use. When planting, use a crane to lower the large tree gently into the planting hole, use scissors to cut open the packaging straw curtain and straw rope, then backfill with stable soil, tread firmly, and water thoroughly.

7. Care and management

① Set up fixing supports: Set up a tripod around the main trunk of the large tree to prevent the large tree from swaying due to human and animal collisions and strong winds.

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

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 should not be too little either, otherwise the tree body will lose water and die.

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

Key points of overwintering care and management for flowers

Key points of overwintering care and management for flowers
1. Cold protection
In simple plastic greenhouses where the temperature is not lower than 0°C, the following ornamental plants can be placed without freezing damage, such as Asparagus densiflorus, Asparagus cochinchinensis, Aspidistra elatior, Fatsia japonica, Aucuba japonica 'Variegata', Livistona chinensis, Nephrolepis cordifolia, Rhapis excelsa, Nandina domestica, Michelia figo, Ardisia crenata, Pyracantha fortuneana, Camellia japonica, Cymbidium goeringii, Cymbidium faberi, Bambusa multiplex f. fernleaf, Sasa fortunei, Cycas revoluta, etc. For ornamental plant species requiring an overwintering temperature not lower than 5°C, such as Araucaria heterophylla, Schefflera octophylla, Ficus elastica, Jasminum sambac, Michelia alba, Chloranthus spicatus, Chamaedorea elegans, Zantedeschia aethiopica, Syngonium podophyllum, Monstera deliciosa, Cymbidium ensifolium, Cymbidium sinense, Rhododendron hybridum, Bougainvillea spectabilis, Cyclamen persicum, Primula malacoides, Lantana camara, Fortunella margarita, Citrus aurantium 'Daidai', Citrus limon, Chrysalidocarpus lutescens, Pelargonium hortorum, Hibiscus rosa-sinensis, Bambusa ventricosa, etc., they can overwinter in double-layer plastic greenhouses. For species requiring an overwintering temperature not lower than 10°C, such as Codiaeum variegatum, Caladium bicolor, Peperomia, Maranta, Dracaena sanderiana, Caryota mitis, Dracaena fragrans, Pachira aquatica, Fittonia, Bromeliaceae, Calathea majestica, Euphorbia pulcherrima, Cymbidium hybridum, Clerodendrum thomsoniae, Pachystachys lutea, Aglaia odorata, Phalaenopsis, Cattleya, Paphiopedilum, Cycas revoluta, Erythrocephala, Oncidium, Cymbidium hookerianum, etc., in well-sealed double-layer greenhouses, appropriate heating should also be provided. During particularly cold periods, from 4 p.m. to 9 a.m. the next day, cover the top of the greenhouse with straw curtains, and remove them after the temperature warms up. For relatively cold-tolerant potted and bonsai plant species, such as Chimonanthus praecox, Prunus mume, Malus, Rhododendron simsii, Punica granatum, Ulmus parvifolia, Sageretia thea, Xylosma racemosum, Lagerstroemia indica, Wisteria sinensis, Buxus, Podocarpus macrophyllus, Acer buergerianum, Sabina chinensis 'Pyramidalis', Sabina chinensis, Sabina virginiana, Adina rubella, Ilex cornuta, Fraxinus, etc., when the temperature is not lower than -10°C, they generally will not freeze; in particularly cold weather, additionally cover with plastic film or soft grass for cold protection.

2. Watering
For most potted flowers and bonsai placed in conservatories, greenhouses, and rooms, keep the potting soil moist. If the temperature is on the low side and watering is excessive, it is very easy to cause root rot. When the temperature rises, increase the amount of watering and provide appropriate leaf surface spraying. For potted flowering plant species that bloom around Spring Festival, such as Camellia japonica, Camellia sasanqua, Rhododendron hybridum, Prunus mume, Chimonanthus praecox, Pericallis hybrida, Primula malacoides, Kalanchoe blossfeldiana, Hyacinthus orientalis, Narcissus, etc., and fruit ornamental types such as Citrus aurantium 'Daidai', Citrus limon, Citrus medica var. sarcodactylis, Fortunella, Glycine, Solanum pseudocapsicum, Ardisia crenata, Nandina domestica, etc., not only should the potting soil be kept moist, but leaf surface spraying must also be provided to facilitate flower bud enlargement and also increase the vividness of flowers and fruits. For most foliage plants placed indoors, keep the potting soil moist and also provide leaf surface spraying to always keep the plant leaf surfaces clean; for relatively less cold-tolerant foliage plant species, such as Calathea majestica, Syngonium podophyllum, Maranta, Codiaeum variegatum, Aglaonema 'Silver Queen', etc., when the room temperature is already close to the minimum temperature limit they can tolerate, special attention should be paid to controlling the amount of watering to ensure they can overwinter safely. The watering time in December is best during the 3 to 4 hours around noon, and the water temperature should be kept basically consistent with the air temperature and soil temperature, to avoid adverse reactions in potted flowers caused by water temperature being too low.

3. Fertilizing
For most potted flowers and trees, foliage plants, bonsai, etc., placed in ordinary greenhouses, fertilization should be stopped, otherwise it is very easy to cause root rot and death of the plants.

4. Pruning
Prune hedges, green walls, and ball-shaped topiary that were not pruned in November. Hedges and green walls include privet, small-leaf privet, Ligustrum sinense, Euonymus japonicus, Sabina chinensis, four-season osmanthus, Photinia davidsoniae, etc.; ball-shaped types include Ilex cornuta, Myrica rubra, Photinia, Buxus, Pittosporum tobira, Forsythia, Pyracantha fortuneana, Sabina chinensis 'Kaizuca', Juniperus rigida, etc. While completing pruning, fertilizer can be applied. For ground-planted flowering trees not pruned in November, such as Rosa chinensis, Lagerstroemia indica, Trachycarpus fortunei, Prunus cerasifera 'Atropurpurea', Photinia, Platanus orientalis, Prunus mume, Chimonanthus praecox, etc., carry out shaping and pruning, and after pruning is completed, bury and apply fertilizer around the root system. For bonsai plant species mainly pruned, such as Ulmus parvifolia, Sageretia thea, Ilex cornuta, Carmona retusa, Acer buergerianum, Xylosma racemosum, Fraxinus, Pyracantha fortuneana, Serissa japonica, Podocarpus macrophyllus, Sabina chinensis 'Pyramidalis', Sabina chinensis, Malus, Chaenomeles, etc., continue pruning in December to lay a good framework for next year's growth; for plants that have not been repotted for many years, repotting can be combined with pruning.

5. Pest and disease control
For flowering trees whose leaves are prone to pests and diseases, such as Vitis, Malus, Rosa rugosa, Rosa chinensis, Camellia japonica, Lagerstroemia indica, etc., collect the fallen branches and leaves under the plants and burn them, which can reduce the occurrence of diseases next year. At the same time, spray lime sulfur mixture for sterilization and disinfection. For powdery mildew on potted Pericallis hybrida and gray mold on Primula malacoides, the former should be controlled promptly with triadimefon or thiophanate-methyl, and the latter with thiophanate-methyl. For species in greenhouse greenhouses that are prone to scale insects, such as Citrus aurantium 'Daidai', Citrus medica var. sarcodactylis, Cycas revoluta, Camellia japonica, Aspidistra elatior, etc., first wipe them once with a cloth, then use pesticides such as Supracide for control. For flowering tree species that commonly develop aphids on potted plants when ventilation is poor, such as Michelia alba, Aglaia odorata, Citrus aurantium 'Daidai', Rosa chinensis, Carmona retusa, etc., tobacco water can be used for control. For the trunks and large branches of open-ground cultivated flowering trees such as Pittosporum tobira, Osmanthus fragrans, Platanus orientalis, Camellia japonica, small-leaf privet, Pyracantha fortuneana, Nerium oleander, Malus, Magnolia denudata, Cercis chinensis, Gardenia jasminoides, Cedrus deodara, Photinia, Lagerstroemia indica, Chimonanthus praecox, etc., where various scale insects often appear, such as Ceroplastes ceriferus, Ceroplastes japonicus, Ceroplastes rubens, Diaspididae, Unaspis yanonensis, Pseudococcidae, Eriococcidae, etc., at this time use higher-concentration pesticides such as Supracide, quinalphos, and buprofezin for spraying and killing, with little phytotoxicity.

6. Composting fertilizer
For next year's seedling raising and preparation of culture soil, use the winter slack time to pour rapeseed cake, soybean cake, tea seed cake, etc., into water vats or water tanks, add water, and seal them for soaking, composting, and fermentation. Stack dry withered grass, fallen leaves, shrubs, branches, etc., in layers with garden soil, ignite and burn them to form burnt soil, which is excellent covering soil for sowing and raising seedlings next year. Mix stable manure, pond mud, chicken droppings, pigeon manure, etc., with garden soil, pile and compost them, and seal for fermentation, which can be used for topdressing seedlings and preparing culture soil the following year.

7. Preparing culture soil
Use the free time in winter to find an open space or a place under tree shade and pile up as much culture soil as possible to prepare for repotting and potting herbaceous flowers next spring. Generally, use 4 parts garden soil, 2 parts leaf mold (or 2 parts alpine humus soil), 1 part fine sand, 1 part each of composted sawdust, tobacco powder, or chaff ash, plus about 5% composted cake fertilizer and 2% to 3% compound fertilizer. The garden soil and leaf mold should be sieved to remove stones, tree roots, and other debris, then mix them thoroughly and cover with plastic film. They can also be piled indoors. After 3 to 4 months, they can be used for repotting or potting herbaceous flowers.

8. Turning soil and freezing clods
For garden land to be used next year for sowing, cuttings, and planting seedlings, plowing can be done in December; for garden land for sowing and planting seedlings, cake fertilizer, stable manure, pond mud, etc., can be applied before turning and planting; do not make beds for the time being, and after overwintering and freezing clods, make trenches and beds in early spring next year, which can greatly reduce the cost of seedling management and also reduce the occurrence of pests and diseases. Ornamental plant species suitable for bonsai shaping in December include: Podocarpus macrophyllus, Thujopsis dolabrata, Sabina chinensis, Sabina chinensis 'Pyramidalis', Chamaecyparis pisifera 'Squarrosa', Platycladus orientalis, Juniperus procumbens, Juniperus chinensis 'Shimpaku', Pinus thunbergii, Pinus parviflora, Pinus densiflora, Adina rubella, Ilex cornuta, Ilex chinensis, Euonymus verrucosoides, Ginkgo biloba, Serissa japonica, Caragana, Ulmus parvifolia, Sageretia thea, Acer buergerianum, Corylopsis, Tamarix, Chaenomeles speciosa, Malus halliana, Chaenomeles, Buxus sinica, Buxus sinica var. parvifolia, Wisteria sinensis, Lagerstroemia indica, Ficus microcarpa, Carmona retusa, Fraxinus, Xylosma racemosum, etc. For bonsai plants fixed and shaped with palm fiber (rope) or metal wire, if the fixation time has already been one year, or obvious constriction marks are found on the trunk or branches, the original binding material should be removed and metal wire or palm rope should be used again for hanging, pulling, and guiding. For ground-planted shaped plum stumps, Podocarpus macrophyllus, Malus, Ginkgo biloba, Sabina chinensis, Lagerstroemia indica, etc., after carrying out some necessary pruning and shaping, choose suitable pots and plant them well, strengthen management, so that they can be used for display in public places or rooms next year.