Southern yew (Taxus wallichiana var. mairei) planting methods: seed collection, processing, and pest and disease control

    The yew is a precious landscaping tree species in China, with a graceful tree shape and evergreen leaves throughout the four seasons. Its fruit is red and it has excellent ornamental and medicinal value. Below are the methods for seed collection, processing, propagation, cultivation, and management of the southern yew, for your reference.

    1 Seed collection and processing

    The seeds mature from November to December. Begin harvesting when the fruit skin turns dark red. Because the maturity time is not uniform, harvest each batch as it ripens. Pile the harvested fruit in a cool, moist place to ferment. After the fruit skin softens, rinse away the flesh with clean water and take out the seeds. The seeds should be rubbed to remove the waxy surface layer. Sun-dry the de-waxed seeds for half a day, then carry out ordinary sand storage at a ratio of seeds : river sand = 1:3, storing until sowing the following year.

    2 Seedling cultivation

    2.1 Sowing and seedling raising

    2.1.1 Selection and preparation of the nursery site

    Choose a paddy field harvested in the current year with deep soil and a loose structure as the nursery site. Deep-plow and break up the soil, then divide into beds. The bed surface is 1.2 m wide and 20 cm high. Apply about 4000 kg of decomposed pig and cattle manure and 100 kg of quick-dissolving high-quality compound fertilizer per mu. Mix the fertilizer thoroughly with the soil through mechanical land preparation. Spread a layer of 3 cm of yellow subsoil on the bed surface.

    2.1.2 Sowing

    Begin sowing when 30% of the seeds show radicles emerging in the following spring. Use broadcast sowing or drill sowing. Broadcast sowing: mix the seeds evenly with burned soil or fine river sand, spread evenly over the bed surface, then cover the bed surface with a layer of 0.5-1.0 cm of yellow subsoil, and cover the bed surface with dry grass. Drill sowing: open sowing furrows about 2 cm deep on the bed surface at a row spacing of 15-20 cm and a plant spacing of 10-15 cm, sow the seeds into the furrows, then cover the bed surface with a layer of 0.5-1.0 cm of yellow subsoil, and cover the bed surface with dry grass and keep it on the bed surface for a long time.

    2.1.3 Seedling stage management

    (1) Shading. After sowing, set up a shade shed 2.0-2.2 m high using shade netting. In the early stage, control shading at about 70%, and in the later stage at about 50%. It must be covered tightly and securely, and guard against wind damage, rodent damage, bird damage, and control of underground pests. Remove the shade netting in late September to allow the seedlings to receive light and enhance lignification.

    (2) Weeding. Weeds tend to grow in the early stage of seedling growth, so weeding must be timely and meticulous, and the number of weedings is relatively high.

    (3) Topdressing. During the seedling stage, use quick-acting nitrogen and phosphorus fertilizers diluted with water at a concentration of 0.1-0.3 to water the bed surface. In the middle and late stages of seedling growth, use quick-acting compound fertilizer diluted with water at a concentration of 0.1-0.3 to water the bed surface once every month. Stop fertilizing after September.

    (4) Water management. This can be combined with topdressing. Seedlings are afraid of waterlogging and must not have standing water.

    (5) Thinning and filling in seedlings. If sowing is uneven and seedlings are too dense, thin them; if too sparse, fill them in. From late May to mid-June, choose cloudy and rainy days or after rain for transplanting. After covering with dry grass, water the base of the plants with clean water.

    (6) Overwintering management. In winter low-temperature freezing weather, cover the seedlings with a layer of dry grass in advance to prevent freezing injury to the seedlings.

    2.2 Nutritional bag seedling raising

    2.2.1 Preparation of nutritional soil and bag filling

    Use local materials such as mountain red loam or forest topsoil and river sand as the nutritional soil. The ratio is: red loam (or forest topsoil) : river sand : burned soil (or plant ash, etc.) = 70% : 20% : 10%. Mix thoroughly. Use 15 cm x 18 cm (caliber x height) non-woven nutritional bags to fill with soil.

    2.2.2 Sowing

    Begin sowing when 30% of the seeds show radicles emerging in the following spring. Use dibbling, sowing 1-2 seeds per nutritional bag.

    2.2.3 Seedling management

    After sowing, set up a shade shed 2.0-2.2 m high using shade netting. In the early stage, control shading at about 70%, and in the later stage at about 50%. Carry out seedling stage management such as cultivating and weeding, fertilizing, watering, and pest and disease control. The management measures are the same as for sowing and seedling raising.

    3 Afforestation

    3.1 Forest land selection

    Because the southern yew is shade-loving, afforestation should preferably be carried out under the forest canopy. Choose shady slopes or semi-shady slopes at middle and lower slope positions or valleys at an altitude of 400-1200 m in mountainous areas, and interplant in forest stands with a canopy density of 0.3-0.5. Mountain afforestation has relatively high requirements for site water and fertilizer conditions. Choose red loam or yellow loam forest land in hilly and mountainous areas as the afforestation site.

    3.2 Forest land clearing

    Completely cut down miscellaneous shrubs and weeds in the forest land. The height of stumps shall not exceed 10 cm. Do not burn the forest land. Stack logging residues in strips along contour lines at intervals of 1.5 m.

    3.3 Land preparation and hole digging

    For afforestation land preparation, hole cultivation should be used, digging open holes. After the holes are dug, backfill the topsoil into the holes to form a steamed bun shape. Apply base fertilizer (phosphate fertilizer). The hole specification is 50 cm x 50 cm x 40 cm. Land preparation is best done in autumn and winter. Plant spacing and row spacing: 1.5 m x 2 m.

    3.4 Planting techniques

    The afforestation season is from January to February. Before planting, soak the seedlings in clean water for 1-2 h. Seedlings transported from afar should be soaked for a longer time to replenish the water lost by the seedlings. When planting, keep the roots spread out, and press firmly with the foot to ensure full contact between the seedling roots and the soil. After planting, insert a support stick to straighten the seedling trunk, and cover the soil surface at the root zone with a layer of straw or weeds.

    4 Tending and management

    4.1 Hoeing weeds and loosening soil

    Tending should be carried out promptly after afforestation. Hoe weeds and loosen the soil every year, the first time in April-May and the second time in August-September.

    4.2 Fertilization

    Fertilization is a key cultivation technique. Fertilize 2 times each year in combination with hoeing weeds and loosening the soil.

    4.3 Bud removal and pruning

    Remove buds and prune the sprouting shoots at the base and the overly dense branches in the middle and lower parts.

    5 Control of main pests and diseases

    The southern yew has relatively few pests and diseases, mainly seedling stage diseases. The common diseases are root rot and damping-off. For control, after the seedlings emerge, spray alternately with 800-fold thiophanate or Bordeaux mixture every 15 d, which gives good control results.

    The yew is an excellent landscaping tree species, combining ornamental value, economic value, and medicinal value. Its planting method is simple, and it is worth planting. The above are the detailed methods for seed collection, processing, propagation, cultivation, and management of the yew, which you can save for reference.

Methods for raising southern yew seedlings under the forest

  Yew is the general name for plants in the genus Taxus. The genus has about 11 species, distributed in the Northern Hemisphere. China has 4 species and 1 variety.

  The yew is a shallow-rooted plant, with an inconspicuous main root and well-developed lateral roots. It is recognized worldwide as a rare natural anti-cancer plant on the verge of extinction. It is an ancient relict tree species left over from the Quaternary glaciation and has a history of 2.5 million years on Earth. Because the yew grows slowly under natural conditions and has poor regeneration ability, for a long time no large-scale yew raw material forest base has been formed worldwide.

How to plant yew_ Yew planting methods

Yew, also known as purple yew, is a “national treasure-level” plant of the genus Taxus. What methods are there for planting such a high-end plant? Today we will tell you about the methods for planting yew, and we hope it will be helpful to you!

Yew growth habits

Yew is suitable for planting in both northern and southern parts of China. It has the characteristics of being shade-loving, drought-tolerant, and cold-resistant, and requires soil pH of 5.5-7.0.

It is shade-tolerant in habitat and can also grow under dense forest. It is perennial and does not form forests. It is mostly seen in coniferous and broad-leaved mixed forests dominated by Korean pine. It grows on rocky or barren soil on mountain tops, mostly in shrub form. In its place of origin, the average annual temperature is 2°C to 7°C, and the average annual precipitation is 750-1000 mm. It is mostly scattered under moist, fertile coniferous and broad-leaved mixed forests on shady or semi-shady slopes. It likes a cool and humid climate and can tolerate low temperatures below minus 30°C. It has strong cold resistance, with an optimum temperature of 20-25°C, and is a shade-loving tree species. It likes moisture but fears waterlogging, and is suitable for planting in loose, moist, well-drained sandy loam.

Yew planting methods

Seed propagation

Yew is mostly propagated by seed. The seeds can be harvested after they mature in November. After that, wash the fleshy seed coat clean and dry it, then immediately stratify and bury it with wet sand in a shady, dry place, covering it with plastic film and straw curtains. In summer and autumn, turn the seeds twice a month. By early March of the following year, they can be sown to raise seedlings. The seedbed should be chosen as a slightly acidic sandy loam plot sheltered from wind and with good drainage. The bed width is 1 m, the ditch width is 40 cm, and high ridges are made in an east-west direction. On both sides of the ridge, bury steel plates 25 cm high and 4 cm thick, at a depth of 10 cm. The bed soil should be deeply plowed and finely cultivated, and carbofuran should be applied to control underground pests. Use vermiculite, river sand, peat, and garden soil in equal parts, and add fungicides such as carbendazim or thiophanate-methyl, mix into a substrate and fill it into the steel plates, level with the side plates and 3-5 cm higher in the middle. Cover with plastic film and seal for fumigation for 3 to 5 days before sowing. Sow the seeds evenly on the bed surface, with a sowing rate of about 200 seeds per square meter. After sowing, press flat slightly with a wooden board, cover with 1 to 2 cm of mixed substrate soil, and cover with straw curtains or plastic film to keep warm and moist. In dry weather, spray water appropriately. Generally, after 40 days, they can germinate and emerge. At this time, remove the plastic film or straw curtains, and set up a 2 m high shade shed above the seedbed, covering it with shade netting to prevent direct sunlight. Keep the seedbed moist. In rainy weather, set up a low arch shed and cover it with plastic film to prevent excessive water in the seedbed. Do a good job in seedbed drainage and ventilation, and timely control pests and diseases. During the seedling stage, apply decomposed dilute cake fertilizer water once every 10 days. Do not use chemical fertilizers or concentrated fertilizers. After one year of careful maintenance and management, the seedlings can reach 15-25 cm in height and have 2-3 forked branches. Transplanting can be carried out in early April. The planting site should be chosen as a slightly acidic sandy loam site sheltered from wind, dry, and rich in humus. Deep-plow 20 cm, and apply 5 kg of decomposed organic fertilizer per square meter. Make high ridges and dig deep ditches. The ridge width is 100 cm and the ditch width is 30 cm. Plant 5 rows per ridge, with a row spacing of 20 cm and a plant spacing of 15 cm. Transplanting should preferably be done on cloudy days, and should be done as the plants are moved, with soil balls required. After transplanting, immediately water thoroughly once, and set up a 2 m high shade shed above it. Cover with shade netting on sunny days, and remove it on cloudy and rainy days and at night. During the growing period, strengthen fertilizer and water management, generally applying decomposed cake fertilizer water once every 10 days. Do a good job in pest and disease control and management. In summer, strengthen shading and cooling work, and if necessary, spray water to cool down, so as to create a cool and humid environment conducive to seedling growth. Yew is not only a superior material for making high-grade furniture, but also a medicinal material with great medical value, and moreover an excellent tree species for landscaping. With the maturity and development of artificial propagation and artificial cultivation techniques, the application scope of yew will become even broader.

When propagating seedlings with yew seeds, pay attention to the storage method of the seeds. They should be stored mixed with sand or treated with temperature control, which has a good effect on sprouting after overwintering and breaking dormancy habits. Before sowing, rub and damage the seed coat, soak the seeds in warm water, and treat with chemicals and hormones. Shading after emergence is key to seedling raising. It can prevent high-temperature scorching of seedlings and maintain moisture, with a suitable light transmittance of 40%. Both Japanese yew and southern yew can achieve an emergence rate of 70-80%, and the emergence temperature is required to be above 15°C.

The dynamic growth of seedling plants is as follows: the plant height and stem diameter of seedling plants grow slowly in the first two years after emergence, with plant height generally increasing by about 10 cm per year. After one year after transplanting, growth accelerates. From 3 to 5 years, the annual increase can reach 20-30 cm.

Cutting propagation

For yew cutting propagation, softwood cuttings are better in spring, and hardwood cuttings are better in autumn. Generally, low shed shading treatment is needed during cutting. The general cutting survival rate can reach more than 70%. Conventional cuttings, however, are only about 3%-20%. The shading rate should not be less than 60%. Careful rooting treatment should be done at the base of the cuttings. At the beginning, humidity should be kept intermittently at about 75-85%. Avoid strong winds causing water loss.

Factors affecting the cutting survival rate generally include: tree age, temperature, chemical treatment concentration, substrate, season, humidity, variety, and other human factors.

In the first year of rooting of cutting seedlings, the aboveground part grows slowly, but rooting is rapid and lateral roots are well developed. After transplanting in the second year, further shading treatment and seedbed management are needed. Ensure corresponding environmental conditions, and growth accelerates. Growth is fastest in summer, and slow in winter and spring. At this time, attention should be paid to temperature changes. Long-term dryness can cause growth inhibition or sudden death. However, after the seedlings are strengthened in the seedbed, the afforestation survival rate of yew is very high. Very few die, and they grow rapidly.

Seedling management

Temperature regulation

After cuttings are inserted, the bed surface ground temperature should be maintained at 18°C-25°C, the temperature inside the shed at 22°C-28°C, and the soil moisture at 60%-70%.

Seedling stage management

Observe the temperature and humidity inside the plastic shed every day. When there are water droplets inside the plastic film of the arch shed, it is not short of water; when there are no water droplets, it is short of water. When short of water, open the plastic film and appropriately let in rain or water. When the temperature inside the shed reaches 30°C, promptly open the plastic at both ends of the arch shed for ventilation. After sunset, seal the plastic film tightly again to maintain the temperature inside the shed. Before snowfall, remove the upper shade netting and move it under the plastic inside the arch shed to continue shading and prevent direct sunlight on the seedlings. About 45 days after cutting, the cuttings begin to root, and after about 65 days they have basically rooted completely. In the same year, they can grow 3-5 cm tender shoots. After 2 years, they can be transplanted, and at this time the root system is relatively well developed and easy to survive. When they grow to 6-8 years, the saplings are 80-90 cm tall.

Weeding and disease prevention

Weeding should be carried out when the weeds have just grown. If the weeds are large and strong-rooted, carelessness may pull out the seedlings together with them, or create air leaks that cause seedling death. Therefore, weed early and frequently to avoid loss of water and fertilizer. In the rainy season, yew seedlings are prone to root rot and stem rot. At this time, spray and irrigate with 70% dexon 400-700-fold solution. In dry and high-temperature seasons, seedlings are prone to leaf blight. Spray 1% Bordeaux mixture for control.

Tissue culture

Tissue culture makes use of the totipotency and clonability of plant cells. The tender stems, needles, bark, cambium, aril, embryos, etc. of yew plants are used as explants for culture research.

1. Select excellent yew varieties as explants, inoculate them into culture medium, and through steps such as callus formation, rooting, and shoot cluster formation, a large number of tissue culture seedlings can be obtained in the laboratory. After substrate transplanting, hardening, and inspection and quarantine, they become production seedlings.

2. The ratio of early to late callus formation in yew differs among different species and among different plants of the same species. At the same time, it is related to factors such as explant type, sampling site and collection season, light conditions, and culture medium type.

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Key points for potted yew care

1. For newly purchased potted yew bonsai, when new buds have just sprouted, try not to spray fertilizer solution on the leaf surface, because at this time the yew bonsai has not truly survived or the leaves are too tender. Fertilizing at this time will cause the tender leaves or tender buds to shrink and curl. This will affect the normal sprouting of new roots. Do not spray too much clean water on the leaf surface; the degree should be that water droplets can be seen on the leaf surface but do not drip down. Spray two hours before dark in the afternoon. Do not leave water droplets at night (even less so when the amount is relatively large), otherwise it will affect the normal growth of tender leaves or cause the leaves to turn yellow, affecting the healthy growth of the plant. (The underside of the leaves can be sprayed more than the upper side, because the upper side of the leaf has a waxy protective film that hinders the absorption of nutrients and water, while the underside of the leaf has no waxy layer and more stomata, so its ability to absorb water and fertilizer is stronger. Therefore, the underside absorbs faster and more than the leaf surface.) Depending on the situation and temperature, do it once a day or two or three times a day. Note that the room needs frequent ventilation.

2. For newly purchased potted yew bonsai, because transplanting from the planting base into the flowerpot damages part of the root system, the nutrient supply between roots and branches and leaves becomes unbalanced. Especially for those bonsai with luxuriant branches and leaves, the transpiration from the leaf surface is greater than the absorption by the root system. While the pot soil remains moist, the top leaves may curl and dry up. At this time, it is best to properly prune the branches and leaves to reduce excessive consumption of water and nutrients by the branches and leaves and help the root system recover growth as soon as possible. At the same time, control watering and keep the pot soil slightly dry to facilitate rapid growth of the root hairs and accelerate the restoration of normal nutrient supply. At the same time, yew has strong sprouting ability, especially strong new branch growth ability and is very tolerant of pruning. After surviving, it will quickly sprout new branches and new leaves. When necessary, plant rooting or root-increasing agents can be used to water the pot soil about once every seven days, for three or four consecutive times (use products of good quality and do not use too much water at the same time), so that the root system can grow quickly and healthily. This will restore the supply balance between roots and leaves as soon as possible and make the yew grow well.

3. Because the nutrients in a potted yew bonsai are limited, they can only provide about half a year of growth needs, or if the plant shape is relatively large, nutrient consumption is very high. Therefore, consumers are advised to replace the original pot as soon as possible after purchase. Because our company carries out a replanting recovery period of more than one month for the bonsai, and it is stored for a period of time in the distribution company, and in addition yew likes fertile and loose soil. It is best to change the pot as soon as possible. When changing the pot, calculate by the inner diameter of the flowerpot. The inner diameter of the new pot should preferably be at least 5 cm larger. Do it before new buds sprout in February or March each year. When the pot soil is neither dry nor wet, pour out the tree together with the pot soil. Try not to break the original soil ball. If after survival the root system is found to be too numerous, the bad roots can be properly cut off. Place the tree into the new pot, fill nutritional soil around it, and press gently and firmly. Only when the soil in the pot is in close contact with the roots can the survival rate be improved; otherwise the plant is not easy to survive or does not grow vigorously. However, the soil must not be pressed too firmly. If it is too firm, the roots cannot breathe air, which will lead to root rot and plant death. After planting, immediately water thoroughly once. Place the pot in a cool place for a few days. After watering, the pot soil must not be turned or pressed again, otherwise the pot soil is likely to become compacted, or the soil may be too firm and poorly ventilated, easily causing root rot.

4. Fertilization methods for potted yew bonsai: the three major elements of plant growth are nitrogen, phosphorus, and potassium fertilizers. Nitrogen fertilizer can promote the growth of flowers, grass, branches, and leaves; phosphorus fertilizer can promote the formation of flowers and fruits; potassium fertilizer can promote the growth of stems and roots.

Because bonsai are cultivated in the limited space of a pot and in limited cultivation soil, organic matter is decomposed by bacteria into inorganic salts and absorbed by roots. As the yew grows and consumes nutrients, the nutrients in the pot soil gradually become insufficient, resulting in an inability to supply growth needs. Although prepared nutritional soil is used in the bonsai, do not fertilize within three months after purchase. Just water with about 1000-fold potassium dihydrogen phosphate solution or spray on the leaf surface once every seven to ten days in the evening. Control the amount of watering; do not water too much. Only when the leaf color becomes lighter, the plant becomes weak, the leaves appear yellow-white, and “dry-burned edges” appear at the leaf margins and tips, and the leaves age prematurely and fall, apply 1000-fold urea solution and 800-fold potassium sulfate quick-dissolving high-quality compound fertilizer solution after removing sediment to the pot soil, about once a month. It is best to use fully decomposed dilute soybean cake fertilizer water (about 10%-15%). When applying, avoid the trunk area and apply as much as possible along the pot wall, once every half month. The next day after fertilizing, water once more with clean water to dilute the fertilizer in case it is too concentrated. The above two fertilizers can be used alternately, or two small holes can be dug in each pot and five or six granules of urea and seven or eight granules of high-quality compound fertilizer placed inside. Then cover with soil and water so the fertilizer dissolves. Potted yew bonsai should avoid raw fertilizer and concentrated fertilizer. Topdressing should mainly be nitrogen and phosphorus fertilizer and must not be too concentrated.

5. Watering methods for bonsai: the principle is “do not water if not dry; when watering, water thoroughly”

Water is an important component of the bodies of flowers and trees. All life activities of flowers and trees must be carried out with the participation of water. Whether photosynthesis or transpiration, none can do without water. Water can maintain cell turgor and keep branches and leaves upright. However, exceeding the limit will instead make the plant grow thin and weak. If there is too much water in the pot soil for a long time, it will cause the leaves to turn yellow, fall off, root rot, and even death.

1. If the color of the pot soil surface has slightly become lighter and the leaves are slightly curled, and pressing the pot soil with a finger feels somewhat soft and loose, and lightly tapping the upper middle part of the pot body with a finger joint gives a relatively dull sound, then the pot soil does not need watering. Just spray the leaf surface to supplement the water in the leaves. When the soil surface turns white, pressing with a finger feels relatively hard, a ring of cracks appears between the pot and the soil, lightly tapping the upper middle part of the pot body with a finger joint gives a clear “bang bang” sound, and the young tips and young leaves wilt, then the pot soil should be watered. Before watering, press the cracks between the soil and the pot firmly with a hard object, then water. Use a large ladle to water. When pouring, the ladle should be close to the pot edge, pour the water in at once, and water thoroughly in one go so that the pot soil absorbs enough water. If a small amount of water is poured into the pot and after a while water is seen flowing quickly out from the bottom of the pot, it indicates that the soil and pot are not completely pressed firmly. Use an object to press the gap between the pot wall and the soil tightly before watering. When the pot soil structure is normal, after watering it is better if water slowly seeps out from the bottom of the pot after about 40 seconds to one minute. The water temperature for watering must be close to or consistent with the temperature at that time. When using tap water, first place the water in sunlight for about three hours before watering, because light helps decompose oxides in tap water and can raise the water temperature. Water can also be placed in a large basin for half a day or overnight before watering. If there are many bonsai, it is best to place the water in a large vat so that the water temperature is as close as possible to the air temperature and soil temperature. Especially in hot seasons, in addition to watering the pot soil, also spray water mist on the leaf surface to keep the leaf surface moist, which is beneficial to growth. The pot soil can be kept slightly dry and must not be too wet. When there are many pots, be sure to check each pot according to the actual situation, and be careful not to miss watering or overwater.

2. Yew leaves are evergreen throughout the four seasons and are suitable for placement indoors. However, potted yew bonsai should not be placed at the air outlet of an air conditioner, otherwise the water evaporation from yew leaves will increase, easily causing rapid dehydration of yew branches and leaves and causing the leaves to curl and dry up. If placed in an air-conditioned room where the air conditioner is turned on every day, spray the leaf surface every day to maintain leaf surface humidity, and place a basin of clean water indoors. If in a heated room in northern winter, it should be placed farther from the radiator, and a basin of clean water should be placed on the radiator to increase indoor air humidity. In summer and autumn, when the temperature exceeds 30°C, strengthen shading and cooling work, and it can be moved to a ventilated room facing north. When necessary, spray water to cool down, so as to create a cool and humid environment conducive to the growth of yew. Also avoid rooms where direct west-facing sunlight shines on the potted yew bonsai. In winter, control the amount of watering of the bonsai and avoid long-term excessive moisture in the pot soil. Because plant growth is not vigorous in winter and leaves transpire less water, if the pot soil is too wet for a long time, the pot soil surface will become compacted and impermeable, easily causing root rot in the plant. When raising yew indoors, be sure to pay attention to frequent indoor ventilation.

3. The soil for yew planting should preferably be loose, rich in humus, fertile, and slightly acidic soil (pH=5.5-7). Do not pour leftover tea water into the potted yew bonsai. If leftover tea water is often poured in, because the tea contains theophylline and other raw alkalies, it will change the soil pH and also have a relatively destructive effect on the organic nutrients in the soil. It inhibits the growth of yew and also causes excessive soil moisture, hindering pot soil ventilation and causing root rot and stem rot. If conditions permit, about once a week, move the potted yew bonsai to the balcony at night to receive dew, and in the morning place it in sunlight for about one or two hours to receive light (before ten o'clock in the morning), which is beneficial to yew growth and improves disease resistance. In summer and autumn, prevent direct sunlight from west-facing windows from shining on the yew, so as to prevent high temperatures from scorching the leaves and affecting ornamental value.

6. Key points to note

1. Because the yew tree is small, pay attention to regulating light. It needs light but should not be placed in strong light for too long. Generally, in summer and autumn, two hours of sun exposure before ten in the morning or after five in the afternoon each day is enough. At ordinary times, receive more scattered sunlight. Otherwise, strong light will scorch the leaves and cause the leaf tips to become scorched yellow. Also maintain indoor ventilation so as not to cause poor growth phenomena such as wilting and drooping due to indoor air being too dry.

2. If a new bonsai shows tender leaves that are dark yellow and lusterless, and the new shoot tips wilt, it is generally caused by watering too frequently and too much, and soil compaction and poor ventilation causing part of the root hairs to rot, weakening the ability to absorb water and fertilizer. For mild symptoms, control the amount of watering, and use a hard and blunt object to gently loosen the surface soil of the pot to make the pot soil breathable. Move it at night to a place where it can receive dew, and move it to a cool place at eight or nine in the morning, which is conducive to healthy root recovery. If within a short period the leaves turn yellow and curl, it indicates severe root rot, so immediately repot to check the root rot condition (normal fibrous roots are tender, plump, and white in shape). If more than half are affected, it generally cannot be saved.

3. Old leaves turn yellow from bottom to top, but new leaves generally grow normally. This is generally caused by not watering thoroughly in one go, watering too little, and root water shortage. Sometimes the top leaves dry up and curl, and dry leaves fall off when touched, but the old leaves grow normally. This is generally also caused by root water shortage, and watering should be done thoroughly in one go. When watering, be sure to first press the cracks along the pot edge firmly with an object to prevent water from quickly leaking out through the cracks after watering. This causes the illusion of thorough watering, and over time the roots will die from water shortage, causing the trunk to die. At night, move it outdoors to receive more rain and dew, and receive two hours of sunlight in the morning and evening to help the yew recover its growth.

4. Yew is suitable for weakly acidic soil. If it is irrigated with alkaline water for a long time, it will cause the leaves to turn from green to yellow, and even cause the leaves to fall off. Therefore, add acidic nutrients or spray the leaves or water the pot soil with a 0.2% ferrous sulfate solution, once every ten days, for three consecutive times. This can make leaves yellowed by alkalinity turn green again.

5. Every year in March and April, yew will sprout a large number of tender buds, which will consume a large amount of nutrients. At this time, the tender buds growing toward the inside can be removed to prevent the branch shape from being too dense and unventilated, causing the leaves to turn yellow or fall off. Thin and prune crossing branches, inward-facing branches, and leggy branches, which can improve ventilation and light transmission and also save excessive consumption of water and nutrients. When tender buds have just sprouted, it is best not to spray liquid fertilizer on the leaf surface, or apply concentrated fertilizer at the roots.

6. For normal fertilization amount, if urea is used alone as nitrogen topdressing, the concentration is generally 0.1%; if potassium dihydrogen phosphate is used alone as phosphorus topdressing, the concentration used is 0.1% to 0.2%, with an interval of seven to ten days between topdressings.