How to Handle Yew with Alkaline Soil, Dry Leaf Edges, and Yellowing New Leaves

Growing Techniques Jan 1, 1970 0 views

Yew (Taxus) is relatively easy to grow, but not everyone has a smooth experience when cultivating it. What should you do when abnormalities appear during cultivation? For instance, what can you do when the leaves turn yellow and the edges dry out? Treating alkaline soil: Yew prefers slightly acidic soil.

1. Treating alkaline soil

Yew (Taxus) prefers slightly acidic soil. If it is watered with alkaline water over a long period, the leaves will turn from green to yellow and may even drop. Therefore, add acidic nutrients, or spray the leaves or water the potting soil with a 0.2% ferrous sulfate solution, once every ten days, for three consecutive times.

Fertilization precautions

Do not fertilize within three months after purchase. Simply water with a roughly 1000-fold dilution of monopotassium phosphate in the evening, or spray it on the foliage, every seven to ten days.
Control the amount of watering; do not water too much.

2. Treating dry leaf edges

When the leaf color becomes pale, the plant grows weak, the leaves turn yellow-white, and "dry scorched edges" appear on the leaf margins and tips, with premature leaf aging and dropping, apply urea and potassium sulfate after removing the sediment and water the potting soil, applying about once a month. It is best to use fully decomposed diluted soybean cake fertilizer water (about 10%-15%). Keep fertilizer away from the trunk and apply it along the inner wall of the pot as much as possible, once every half month.

On the second 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. Alternatively, dig two small holes in each pot and place five or six granules of urea and seven or eight granules of high-quality compound fertilizer inside, then cover with soil and water so the fertilizer dissolves. Yew bonsai should avoid raw fertilizer and concentrated fertilizer. Topdressing should be mainly nitrogen and phosphorus fertilizer, and must not be too concentrated.

3. Placement precautions

Yew bonsai should not be placed at the air outlet of an air conditioner, as the branches and leaves will quickly dehydrate, and the leaves will curl and dry up.

If placed in an air-conditioned room where the air conditioner runs every day, spray the foliage daily to maintain leaf moisture, and place a basin of clean water in the room.

In northern rooms with heating in winter, keep it farther from the radiator, and place a basin of clean water on the radiator to increase indoor air humidity.

4. Summer and winter care

In summer and autumn, when the temperature exceeds 30°C, strengthen shading and cooling measures; it can be moved to a ventilated room facing north. If necessary, spray water to cool it down, creating a cool and humid environment to benefit the growth of the yew.

Avoid direct afternoon west-facing sunlight shining on the yew. In winter, control the amount of watering for the bonsai and avoid the potting soil being too wet for a long time. Since the plant grows weakly in winter and the leaves transpire less water, if the potting soil is too wet for a long time, the surface of the potting soil will become compacted and impermeable, which can easily cause root rot. When growing indoors, be sure to ensure good indoor ventilation.

5. Yellowing new leaves

If the tender leaves appear dark yellow and lusterless, and the growing tips at the top of new shoots wilt, it is generally caused by watering too frequently and too much, causing the soil to compact and become impermeable, so that part of the root fibers rot and the ability to absorb water and nutrients weakens. For mild symptoms, control the amount of watering, use a hard but blunt object to gently loosen the surface soil of the pot to make the potting soil breathable, move it at night to a place where it can receive dew, and move it to a shady spot at eight or nine in the morning, which helps the root system recover healthy growth.

If the leaves yellow and curl within a short period, it indicates severe root rot. Immediately repot and 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.

6. Yellowing old leaves (leaves drop at a touch)

When old leaves turn yellow but new leaves are normal, it is generally caused by not watering thoroughly in one go, with too little water causing root water shortage.

The leaves at the top dry up and curl, and a large patch falls at a touch, also caused by root water shortage; water thoroughly in one go.

Handling method:

Before watering, first press down the cracks along the pot rim with an object to prevent water from quickly leaking out through the cracks. At night, it can be moved outdoors to receive rain and dew. Two hours of morning and evening sunlight can help the yew recover its growth.

7. Small care tips:

Every year in March and April, the yew will sprout a large number of tender buds, which consumes a lot of nutrients. At this time, you can remove the tender buds growing toward the inside to prevent the branches from becoming too dense and poorly ventilated, which would cause the leaves to yellow or drop. Thin out crossing branches, inward-growing branches and leggy branches, which can improve ventilation and light penetration, and save excessive consumption of water and nutrients. When the tender buds have just sprouted, it is best not to spray liquid fertilizer on the foliage or water concentrated fertilizer at the roots.

That is all for how to handle abnormalities that appear during yew cultivation. In this way, the yew can be grown happily.

How to Grow Yew in Pots

[Introduction] Yew is a shade-loving plant and should not be exposed to sun by the window. Spray water on the foliage every day to maintain humidity. It is a shade-loving plant at all times, but it does not mean no sunlight at all. You can let it get some sun here, but in moderation. Ventilate twice in the morning and evening, 15 minutes each time. The best ventilation time is 9-10 in the morning. On hot days, spray water twice a day, until water drips from the leaves. When watering and irrigating, be sure to water thoroughly in one go, and avoid watering every few days.

Yew (Taxus) 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 tree species left over from the Quaternary glaciation, with a history of 2.5 million years on Earth.

Because under natural conditions the yew grows slowly and has poor regeneration capacity

1. Yew likes shade and should not be exposed to direct sunlight. Placing it in the living room, bedroom, or the corner of a balcony is fine. In the evening, it can be placed on a windowsill to let it breathe. 2. The choice of watering time can be judged from the following aspects: (1) Yew leaves are upright and glossy. If the leaves appear wilted, it is time to water. If the leaves droop, it indicates severe water shortage. (2) Tap the pot lightly a few times with your hand; you can judge from the sound. If the sound is hollow, it means the soil is dry and it is time to water. (3) Judge from the potting soil: insert a finger 2-3 cm into the soil; if you feel the soil is dry, it is time to water.

At different stages, plants need different amounts of water. During the growing season (March to November), they need more water; during the dormant period (December to February), they need less. As for the watering interval, it cannot be generalized. In spring and autumn, water generally once every 5-7 days; in summer, once every 3-5 days; in winter, water thoroughly once every 7-10 days.

3. Surrounding environment. Yew does not have great demands on the environment. Besides doing the first point of avoiding direct sunlight, also note not to let it face the air conditioner directly indoors, not to place it near heating in winter, and not to casually throw cigarette butts, tea leaves and other debris into the pot.

4. If the foliage turns withered and yellow or has pests and diseases, water or spray with thiophanate-methyl or monopotassium phosphate. The general dosage is: one small bag mixed with 1-2 liters of water.

5. Yew needs good ventilation and should avoid direct sunlight. In summer, do not let it face the air conditioner directly; in winter, do not place it near heating.

6. Because the northern climate is dry with little rain, water when the soil surface is dry, and be sure to water thoroughly in one go, especially in summer. The northern air is dry, and the leaf surface easily loses water and droops. When the foliage looks not plump, use a small spray bottle to spray water on the foliage from bottom to top (in summer, it can be sprayed every day). Yew is a shade-loving plant and is suitable for indoor placement, but it should not be placed at the air outlet of an air conditioner or beside heating, otherwise the leaf moisture evaporation of the yew will increase, easily causing the branches and leaves of the yew to dehydrate quickly, resulting in curled and dried leaves.

7. Yew bonsai should not be watered with tea water. Especially in Beijing, where the water is relatively hard and has high alkalinity, the water must be left to stand for a day before being used for watering and spraying.

"Pest and disease control": For southern yew (Taxus wallichiana var. mairei) during the rainy season, individual young trees may develop root rot, stem rot and root rot. A 500-800 fold dilution of 70% dexon can be used; in high-temperature and dry seasons, individual young trees may develop leaf blight and red blight, which can be controlled by spraying 1% Bordeaux mixture. Southern yew young trees rarely have insect pests.

"Bonsai shaping": Southern yew grows vigorously and tolerates pruning, and can be shaped at will. Through artificial means, it can be pruned into southern yew bonsai in various shapes such as umbrella, pagoda and round. At the same time, in order to maintain a beautiful crown width of the yew, the terminal buds and some lateral buds can be moderately removed.

1. For newly purchased yew bonsai when they have just sprouted new buds, try not to spray fertilizer liquid on the foliage, because at this time the yew bonsai has not truly survived or the leaves are too tender. If fertilized at this time, the tender leaves or tender buds will shrink and curl, thereby affecting the normal sprouting of new roots. Do not spray too much clean water on the foliage; 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, and do not leave water droplets at night (especially not when the amount is larger), 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 nutrients 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 yew bonsai about 40 cm tall, because transplanting from the growing base into the pot damages part of the root system, the nutrient supply between the roots and the branches and leaves becomes imbalanced. Especially for those bonsai with luxuriant branches and leaves, the transpiration of the foliage is greater than the absorption of the root system. When the potting soil remains moist, the top leaves 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 its growth as soon as possible. At the same time, control watering and keep the potting soil slightly dry, so as to facilitate the rapid growth of root fibers and speed up the restoration of normal nutrient supply. At the same time, yew has a strong sprouting ability, especially new branches have strong growth ability and are very tolerant of pruning; after surviving, it will soon sprout new branches and new leaves. If necessary, plant rooting or root-increasing agents can be used to water the potting 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 helps restore the supply balance between roots and leaves as soon as possible, so that the yew grows well.

3. Because the nutrients in a yew bonsai planted in a pot are limited and can only provide about half a year of growth needs, or because the current plant shape is relatively large and consumes a lot of nutrients, it is recommended that consumers repot the original pot as soon as possible after purchase. Because our company gives the bonsai a repotting recovery period of more than one month, and it is then stored for a period at the distributor, and because yew likes fertile, loose soil, it is best to repot as soon as possible. When repotting, calculating by the inner diameter of the pot, the new pot's inner diameter should be at least 5 cm larger. Do this before new buds sprout in February or March each year. When the potting soil is neither dry nor wet, pour out the tree together with the potting soil. Try not to break the original soil ball. If after survival you find there are too many roots, you may properly trim off the bad roots, place the tree into the new pot, fill nutrient soil around it and gently press it firm. Only by closely connecting the soil in the pot with the roots can the survival rate be improved; otherwise the plant will not easily survive or grow vigorously. But do not press the soil too firmly either; if it is too firm, the roots cannot breathe air, which will cause root rot and plant death. Immediately after planting, water thoroughly once. And place the pot in a cool place for a few days. After watering, the potting soil should not be turned or pressed again, otherwise the potting soil will easily compact, or the soil will be too firm and poorly aerated, easily causing root rot.

4. Fertilization method for yew bonsai: Plant growth requires 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 the bonsai is grown in limited pot space and limited cultivation soil, organic matter is decomposed by bacteria into inorganic salts and absorbed by the roots. As the yew grows and consumes nutrients, the nutrients in the potting soil gradually become insufficient, resulting in an inability to supply the needs of growth. Although prepared nutrient soil is used in the bonsai, do not fertilize within three months after purchase. Simply water with a roughly 1000-fold dilution of monopotassium phosphate in the evening, or spray it on the foliage, every seven to ten days. Control the amount of watering; do not water too much. Only when the leaf color becomes pale, the plant grows weak, the leaves turn yellow-white, "dry scorched edges" appear on the leaf margins and tips, and the leaves age prematurely and drop, apply a 1000-fold dilution of urea and an 800-fold dilution of instant high-quality compound fertilizer solution after removing the sediment and water the potting soil, applying about once a month. It is best to use fully decomposed diluted soybean cake fertilizer water (about 10%-15%). When applying, keep away from the trunk and apply along the inner wall of the pot as much as possible, once every half month. On the second 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. Alternatively, dig two small holes in each pot and place five or six granules of urea and seven or eight granules of high-quality compound fertilizer inside, then cover with soil and water so the fertilizer dissolves. Yew bonsai should avoid raw fertilizer and concentrated fertilizer. Topdressing should be mainly nitrogen and phosphorus fertilizer, and must not be too concentrated.

5. Watering method for bonsai: The principle is "do not water if not dry; when watering, water thoroughly."

Water is an important component of the body of flowers and trees. All life activities of flowers and trees must be carried out with the participation of water. Whether photosynthesis or transpiration, water is indispensable. Water can maintain cell turgor and keep branches and leaves upright. However, beyond the limit, the plant will instead grow thin and weak. If there is too much water in the potting soil for a long time, it will cause the leaves to turn yellow, defoliate, root rot, and even death.

(1) If the surface color of the potting soil becomes slightly lighter, the leaves are slightly curled, pressing the potting soil with a finger feels somewhat soft, and tapping the upper middle part of the pot with a finger joint gives a relatively dull sound, then the potting soil does not need watering; just spray the foliage to supplement the leaf moisture. When the soil surface turns white, pressing with a finger feels relatively hard, a ring of cracks appears between the pot and the soil, tapping the upper middle part of the pot with a finger joint gives a crisp "bang bang" sound, and the young leaves at the new shoot tips wilt, then the potting soil should be watered. Before watering, press down the cracks between the soil and the pot with a hard object, then water. Use a large ladle to water; when pouring, the ladle should be close to the pot rim, pour the water in all at once, and water thoroughly in one go so that the potting soil absorbs enough water. If a small amount of water is poured into the pot and water is seen quickly flowing out from the bottom of the pot after a while, it means the soil and pot are not completely pressed together, and an object should be used to press the gap between the pot wall and the soil tight before watering. When the potting soil structure is normal, 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 the time. When using tap water for watering, first place the water in the sun for about three hours before watering, because light helps decompose oxides in tap water and can raise the water temperature. You can also place the water 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, besides watering the potting soil, also spray water mist on the foliage to keep the leaf surface moist, which is beneficial to growth. The potting soil can be kept slightly dry and must not be too wet. When there are many pots, be sure to inspect each pot according to the actual situation, and be careful not to miss watering or overwater.

(2) Yew leaves remain green all year round and are suitable for indoor placement. However, yew bonsai should not be placed at the air outlet of an air conditioner, otherwise the leaf moisture evaporation of the yew will increase, easily causing the branches and leaves of the yew to dehydrate quickly, resulting in curled and dried leaves. If placed in an air-conditioned room where the air conditioner runs every day, spray the foliage daily to maintain leaf moisture, and place a basin of clean water in the room. If in a northern room with heating in winter, keep it farther from the radiator, and place a basin of clean water on the radiator to increase indoor air humidity. In summer and autumn, when the temperature exceeds 30°C, strengthen shading and cooling measures; it can be moved to a ventilated room facing north. If necessary, spray water to cool it down, creating a cool and humid environment to benefit the growth of the yew. Also avoid rooms where afternoon west-facing sunlight shines directly on the yew bonsai. In winter, control the amount of watering for the bonsai and avoid the potting soil being too wet for a long time. Since the plant grows weakly in winter and the leaves transpire less water, if the potting soil is too wet for a long time, the surface of the potting soil will become compacted and impermeable, which can easily cause root rot. When growing yew indoors, be sure to ensure good indoor ventilation.

(3) The soil for planting yew should preferably be loose, rich in humus, fertile, and slightly acidic (pH=5.5-7). Do not pour tea water into the yew bonsai. If leftover tea water is often poured in, because tea water 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 the yew and also causes excessive soil moisture, hindering the breathability of the potting soil and causing the occurrence of root rot and stem rot. If conditions permit, about once a week, move the yew bonsai to the balcony at night to receive dew, and in the morning place it in the sun for about one or two hours to receive light (before ten in the morning), which is beneficial to the growth of the yew and improves disease resistance. In summer and autumn, prevent afternoon west-facing sunlight from shining directly on the yew through the window, so as to prevent high temperatures from scorching the leaves and affecting the ornamental value.

6. (1) Points to note: Because Yew No. 2 and No. 3 are small trees, pay attention to regulating light. They need light but should not be placed in strong light for too long. Generally, in summer and autumn, about two hours of sun before ten in the morning or after five in the afternoon is enough. At ordinary times, receive more scattered sunlight. Otherwise, the leaves will be scorched by strong light and the leaf tips will turn scorched yellow. Also maintain indoor ventilation so that the plant does not show wilting, drooping and other poor growth phenomena due to indoor air being too dry.

(2) If a new bonsai shows tender leaves that are dark yellow and lusterless, and the growing tips at the top of new shoots wilt, it is generally caused by watering too frequently and too much, causing the soil to compact and become impermeable, so that part of the root fibers rot and the ability to absorb water and nutrients weakens. For mild symptoms, control the amount of watering, use a hard but blunt object to gently loosen the surface soil of the pot to make the potting soil breathable, move it at night to a place where it can receive dew, and move it to a shady spot at eight or nine in the morning, which helps the root system recover healthy growth. If the leaves yellow and curl within a short period, it indicates severe root rot. Immediately repot and 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 the bottom upward, but new leaves generally grow normally. This is generally caused by not watering thoroughly in one go, with too little water causing root water shortage. Sometimes the top leaves dry up and curl, and dry leaves fall at a touch, but the old leaves grow normally; this is generally also caused by root water shortage, and you should water thoroughly in one go. When watering, be sure to first press down the cracks along the pot rim with an object to prevent water from quickly leaking out through the cracks after watering, creating the false appearance of thorough watering; over time, this will cause the roots to die from water shortage and cause the trunk to die. At night, move it outdoors to receive more rain and dew; two hours of morning and evening sunlight will help the yew recover its growth.

(4) Yew prefers slightly acidic soil. If it is watered with alkaline water over a long period, the leaves will turn from green to yellow and may even drop. Therefore, add acidic nutrients, or spray the leaves or water the potting 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, the yew will sprout a large number of tender buds, which consumes a lot of nutrients. At this time, you can remove the tender buds growing toward the inside to prevent the branches from becoming too dense and poorly ventilated, which would cause the leaves to yellow or drop. Thin out crossing branches, inward-growing branches and leggy branches, which can improve ventilation and light penetration, and save excessive consumption of water and nutrients. When the tender buds have just sprouted, it is best not to spray liquid fertilizer on the foliage or water concentrated fertilizer at the roots.

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

Potted Yew

For potted yew, loam soil is best. You can also choose peat soil, perlite, etc., mixed with loam to form a composite substrate. Water retention, fertilizer retention and breathability are beneficial to the growth of yew. Although clay retains water and fertilizer, it is not breathable, which is not conducive to the growth and development of the yew root system. Although sandy soil is breathable, it has poor fertilizer and water retention, and is also not conducive to yew growth. The best light for yew is from 7 to 11 in the morning every day, about 4 hours of light per day. In summer, the light time should be shorter; in autumn and spring, the light time can be longer. But no light at all also affects the photosynthesis and growth of the yew.

Yew Cultivation Methods and Precautions

Chinese scientific name: Yew (Hongdoushan)

Latin scientific name: Taxus chinensis (Pilger) Rehd.

Other names: Chinese arborvitae, Hongdou tree, Zisha

Binomial name: Taxus chinensis

Kingdom: Plantae

Division: Pinophyta

Subdivision: Gymnospermae

Class: Pinopsida

Order: Taxales

Family: Taxaceae

Genus: Taxus

Species: Taxus chinensis

Distribution area: Mainly produced in Shaanxi, Sichuan, Yunnan, Guizhou, Hubei, Gansu, Hunan, Guangxi and other places

Environmental distribution: Cold high-altitude limestone mountainous areas

Ecological habit: Shallow-rooted plant

Life form: Evergreen tree

Sunlight: Shade-loving

Water: Drought-tolerant

Temperature: Optimum temperature 20-25°C

Soil: Sandy loam

Altitude: Up to 1000-1200 m above sea level

Edible value: The leaves and fruit peel can be processed into tea

Medicinal value: Diuretic and swelling-reducing

Industrial value: Purification of taxol, wood carving

Special use: Greening and ornamental

Toxicity: Toxic

Symbolic meaning: Longevity

Plant height: About 30 m tall

Yew (Taxus), also known as Zisha, is a plant of the genus Taxus. 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, with a history of 2.5 million years on Earth. Because under natural conditions the yew grows slowly and has poor regeneration capacity, for a long time no large-scale yew raw material forest base has been formed worldwide. In 1994, yew was designated by China as a first-class rare and endangered protected plant, and at the same time it is called a "national treasure" by all 42 countries in the world that have yew. The United Nations has also explicitly banned its felling. It is truly a "plant giant panda." Yew is an evergreen tree, with branchlets alternate, turning yellow-green or pale reddish-brown in autumn; winter bud scales rounded on the back or with blunt ridge; sickle-shaped leaves, in two rows, 1.5-3 cm long, broader than other species of the genus Taxus, with a pointed and slender tip, and two yellow bands on the underside of the leaf; flowers axillary, dioecious, female flower with only one ovule, subtended by several scales; flat oval seeds, each side with an inconspicuous ridge, surrounded by a red cup-shaped aril.

1. Morphological characteristics

Yew can reach 30 m tall, with a diameter at breast height of 65-100 cm; bark grayish-brown, reddish-brown or dark brown, splitting into strips and falling off; large branches spreading, one-year-old branches green or pale yellow-green, turning green-yellow or pale reddish-brown in autumn; two- and three-year-old branches yellow-brown, pale reddish-brown or grayish-brown; winter buds yellow-brown, pale brown or reddish-brown, glossy; winter bud scales rounded on the back or with blunt ridge; leaves linear, dioecious, seeds flat and round. The seeds are used to extract oil and can also be used medicinally. It is a shallow-rooted plant with an inconspicuous main root and well-developed lateral roots.

LeavesSpirally alternate, twisted at the base into two rows, linear and slightly curved, 1-2.5 cm long, 2-2.5 mm wide, leaf margin slightly recurved, leaf tip gradually pointed, with 2 wide yellow-green or gray-green stomatal bands on the underside of the leaf, densely covered with small raised dots on the midrib, green band at the leaf margin extremely narrow, dioecious, male cones solitary in leaf axils, ovules of female cones solitary at the top of the lateral short axis on the upper part of the flower axis, with a disc-shaped aril at the base. Seeds flat ovate, with 2 ridges, seed ovate, aril cup-shaped, red.

2. Growth habits

YewSuitable for planting in both northern and southern parts of China, it has the characteristics of shade-loving, drought-tolerant and cold-resistant, and requires a soil pH of 5.5-7.0.
Its habitat is shade-tolerant, and it can also grow under dense forest, perennial, not forming forests. It is mostly seen in mixed coniferous and broad-leaved 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 annual average temperature is 2°C to 7°C, and the annual average precipitation is 750-1000 mm. It is mostly scattered under moist, fertile mixed coniferous and broad-leaved forests on shady or semi-shady slopes. It likes cool and humid climates, can withstand low temperatures below minus 30°C, has strong cold resistance, and the optimum temperature is 20-25°C. It is a shade-loving tree species. It likes humidity but fears waterlogging, and is suitable for planting on loose, moist, well-drained sandy loam.

3. Distribution range

Widely distributed in Lechang, Guangdong, Shaanxi, Hubei, western Anhui, and as far as Sichuan, Tongren City in Guizhou, the Fanjing Mountain and Foding Mountain areas, most of southwestern Chongqing, the Youyang Daban Ying primeval forest, southern Gansu and other places.
Except for Austrotaxus spicata in Australia, which is produced in the Southern Hemisphere, all other yews are produced in the Northern Hemisphere. There are 4 species and 1 variety of Chinese yew, distributed in most parts of China. The northeastern yew is mainly distributed in the Changbai Mountains of Jilin Province and the Heilongjiang area, with a small amount also distributed in the mountainous areas of eastern Liaoning. Yunnan yew is mainly distributed in 16 counties in western Yunnan and prefectures, with a total area of about 90,000 sq km. Its characteristics are wide distribution, scattered growth, no pure forests, and mostly scattered trees in forests. Southern yew is mainly distributed in eastern Yunnan, southwestern Yunnan, and eastern Yunnan in pure forests, mostly scattered trees in forests.

4. Related species

Yew (original variety) Taxus chinensis (Pilger) Rehd. var. chinensis
Tree, up to 30 m tall, diameter at breast height up to 60-100 cm; bark grayish-brown, reddish-brown or dark brown, splitting into strips and falling off; large branches spreading, one-year-old branches green or pale yellow-green, turning green-yellow or pale reddish-brown in autumn; two- and three-year-old branches yellow-brown, pale reddish-brown or grayish-brown; winter buds yellow-brown, pale brown or reddish-brown, glossy, bud scales triangular-ovate, without ridge on the back or with a longitudinal ridge, falling off or a few persistent at the base of branchlets. Leaves arranged in two rows, linear, slightly curved or relatively straight, 1-3 (mostly 1.5-2.2) cm long, 2-4 (mostly 3) mm wide, upper part slightly narrowing, apex often slightly acute, rarely acute or acuminate, upper surface dark green, glossy, lower surface pale yellow-green, with two stomatal bands, the midrib band densely and evenly covered with small round cuticular papillae, often the same color as the stomatal bands, rarely lighter. Male cones pale yellow, stamens 8-14, anthers 4-8 (mostly 5-6).
Seeds borne in a cup-shaped red fleshy aril, sometimes borne on a nearly membranous disc-shaped seed receptacle (that is, the ovule receptacle that has not developed into a fleshy aril), often ovate, narrowing toward the upper part, rarely obovate, 5-7 mm long, 3.5-5 mm in diameter, slightly flat or round, upper part often with two blunt ridges, rarely upper part triangular with three blunt ridges, apex with a protruding short blunt tip, hilum nearly round or broadly elliptic, rarely triangular-round.
Produced in southern Gansu, southern Shaanxi, Sichuan, northeastern and southeastern Yunnan, western and southeastern Guizhou, western Hubei, northeastern Hunan, northern Guangxi and southern Anhui (Huangshan), often growing on the upper part of high mountains above 1000-1200 m above sea level. Cultivated in Lushan, Jiangxi.
Southern yew (variety) Taxus chinensis (Pilger) Rehd. var. mairei (Lemee et Levl.) Cheng et L. K. Fu
The main difference between this variety and yew is that the leaves are often wider and longer, mostly curved sickle-shaped, usually 2-3.5 (-4.5) cm long, 3-4 (-5) mm wide, upper part often gradually narrowing, apex acuminate, lower midrib band without cuticular papillae, or locally with patchy or scattered cuticular papillae, or with one to several cuticular papillae on both sides of the midrib band adjacent to the stomatal bands; the midrib band is clearly visible, its color different from the stomatal bands, pale yellow-green or green, and the green marginal band is also wider and more obvious; seeds usually larger, slightly flat, mostly obovate, upper part wider, rarely columnar-oblong, 7-8 mm long, 5 mm in diameter, hilum often elliptic.
Produced in southern Anhui, Zhejiang, Taiwan, China, Fujian, Jiangxi, northern Guangdong, northern and northeastern Guangxi, Hunan, western Hubei, western Henan, southern Shaanxi, southern Gansu, Sichuan, Guizhou and northeastern Yunnan. Its vertical distribution is generally lower than that of yew, and in most provinces it often grows below 1000-1200 m above sea level.

5. Conservation status

Current status

Because the bark of yew contains an anti-cancer substance, taxol, many people enter the forest to strip the bark, causing the number of yews to drop sharply. The reason the yew suffered a catastrophe is that in the early 1990s, a certain American company discovered that taxol in yew bark has anti-cancer effects. When the news spread to China and to Yunnan, people suddenly realized that treasure was right beside them. People frantically stripped the bark of yews, and no one took the detailed Regulations on the Protection of Precious Tree Species in Yunnan Province to heart. As a result, more and more yew lives came to an abrupt end overnight.
The State Forestry Administration once made a clear instruction on the "Yew Project": "Yew is a first-class protected tree species in China, with both good ecological benefits and extremely high economic value. The state supports vigorously building yew forests within an appropriate range, and participation by all sectors of society in afforestation and greening undertakings in various forms such as contracting, leasing, auctioning and joint-stock cooperation should be advocated and encouraged."

Nature reserves

Liangyeshan National Nature Reserve is China's first national-level yew nature reserve, and also the only national-level nature reserve with southern yew as its protection target.
The Muling Northeastern Yew Nature Reserve was approved as a national-level nature reserve in 2009, and more than 160,000 northeastern yews, known as the "plant giant panda," will be further effectively protected.
This nature reserve was originally a provincial-level reserve, and is the largest and best-preserved concentrated distribution area of wild northeastern yew discovered so far in the northeastern forest region. Northeastern yew, also known as Zisha, is a world endangered species and a national first-class rare protected tree species.
The Muling Northeastern Yew Nature Reserve is located at the northern end of the Changbai Mountains and the southern foot of the Lesser Khingan Mountains, within the jurisdiction of the Muling Forestry Bureau, with a total area of 35,000 hectares.

Millennium yew

The millennium yew is in Group 3 of Huangdi Temple Village, Duba Township, Beichuan, and is called a "sacred tree" by the locals. According to measurement, the tree circumference is 5.3 m, the tree height is 24.7 m, and the trunk requires 4 adults to encircle it. Beichuan has built a fence around the tree and assigned a dedicated person to protect it. 68-year-old villager Luo Jingcheng said that because the locals regard the tree as a "sacred tree," even though it produces too many red beans every year, no villager will climb the tree to pick them; they only pick up the red beans under the tree.

6. Cultivation Techniques

Propagation Methods

Seed Propagation
Yew (Taxus) is mostly propagated from seed. The seeds mature and can be harvested in November; after that, the fleshy seed coat is washed clean and dried, then immediately stratified and buried in moist sand in a shady, dry place, covered with plastic film and straw mats. In summer and autumn, the seeds should be turned twice a month, and by early March of the following year they can be sown for seedling raising. The seedbed should be chosen on a slightly acidic sandy loam plot that is sheltered from wind and well drained, with a bed width of 1 m and a trench width of 40 cm, with high ridges running east-west, and steel plates 25 cm high and 4 cm thick buried 10 cm deep on both sides of the ridge. The bed soil should be deep-plowed and finely worked, and carbofuran should be applied to control underground pests. Use equal parts vermiculite, river sand, peat and garden soil, 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, then sow. Scatter the seeds evenly on the bed surface at a sowing rate of about 200 seeds per sq m; after sowing, press flat slightly with a wooden board, cover with 1 to 2 cm of the mixed substrate soil, and cover with straw mats or plastic film to keep warm and moist. In dry weather, spray water appropriately; generally, germination and emergence occur after 40 days. At this point, remove the plastic film or straw mats, and set up a 2 m high shade shed above the seedbed, covered with shade netting to prevent direct sunlight. Keep the seedbed moist; on rainy days, set up a low arch shed and cover with plastic film to prevent excessive water in the seedbed. Do a good job of drainage and ventilation of the seedbed, and promptly control pests and diseases. During the seedling stage, apply decomposed dilute cake fertilizer water once every 10 days; avoid chemical fertilizers and 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 a wind-sheltered, dry, humus-rich, slightly acidic sandy loam, deep-plowed 20 cm, with 5 kg of decomposed organic fertilizer applied per sq m. Form high ridges and dig deep trenches, with a ridge width of 100 cm and a trench width of 30 cm. Plant 5 rows per ridge, with a row spacing of 20 cm and a plant spacing of 15 cm. Transplanting is best done on cloudy days, and the plants should be planted immediately after being moved, with soil balls attached. After transplanting, water thoroughly at once, and set up a 2 m high shade shed above; 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 of 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 moist environment conducive to seedling growth. Yew is not only a top-grade material for making high-end furniture, but also a medicinal material of great medical value, and moreover an excellent tree species for landscaping. With the maturity and development of its artificial propagation and artificial cultivation techniques, the application scope of yew will become even broader.
When propagating seedlings from yew seeds, attention should be paid to the storage method of the seeds; mixed sand storage or temperature-controlled treatment should be used, which has a very good effect on sprouting after overwintering and breaking dormancy. Before sowing, the seed coat should be rubbed and damaged, the seeds soaked in warm water, and treated with chemicals or hormones. After emergence, shading is key to seedling raising. It can prevent high-temperature scorching of the seedlings and maintain moisture; a light transmittance of 40% is appropriate. The emergence rate of both Taxus cuspidata (Japanese yew) and Taxus wallichiana var. mairei (Chinese yew) can reach 70-80%, and the emergence temperature is required to be above 15 degrees.
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, and growth accelerates after one year of transplanting. From 3 to 5 years, the annual increase can reach 20-30 cm.
Cutting Propagation
For the cutting propagation of yew, softwood cuttings are better in spring and hardwood cuttings are better in autumn. Generally, low-shed shading treatment is required during cutting. The survival rate of general cuttings can reach more than 70%. Conventional cuttings, however, only reach 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 maintained intermittently at about 75-85%. Avoid strong winds causing water loss.
The factors affecting the survival rate of cuttings generally include: tree age, temperature, concentration of chemical treatment, substrate, season, humidity, variety, and other human factors, etc.
During the rooting process in the first year, the aboveground part of the cutting seedlings 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. With the corresponding environmental conditions ensured, 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 cutting, the bed surface soil temperature should be maintained at 18°C-25°C, the temperature inside the shed at 22°C-28°C, and the soil humidity 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 lacking water; when there are no water droplets, it is lacking water. When lacking water, open the plastic film to let in rain appropriately 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, continuing to shade to prevent direct sunlight on the seedlings. About 45 days after cutting, the cuttings begin to root, and by about 65 days they have basically rooted fully; in that year they can grow 3-5 cm of tender shoots. After 2 years, transplanting can be carried out; at this time the root system is relatively well developed and easy to survive. When they grow to 6-8 years, the saplings reach 80-90 cm in height.
Weeding and Disease Prevention
Weeding should be carried out when the weeds have just emerged. If the weeds are large and their roots strong, carelessness may pull out the seedlings along with them, or create air leaks that cause seedling death, so weeds should be pulled 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, 70% dexon at 400-700 times dilution can be sprayed and poured: in dry and high-temperature seasons, seedlings are prone to leaf blight, and spraying 1% Bordeaux mixture can be used 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 the culture medium, and through steps such as callus formation, rooting, and seedling bud cluster formation, a large number of tissue-cultured 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 medium type.

Potted Maintenance

1. For newly purchased potted yew bonsai that have just sprouted new buds, 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 affects 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 larger), 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 has 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 flower pot damages part of the root system, the nutrient supply between the roots and the branches and leaves becomes unbalanced. Especially for those bonsai with luxuriant branches and leaves, the transpiration of the leaves is greater than the absorption of the root system; while the pot soil remains moist, the top leaves curl and dry up. At this time, it is best to prune the branches and leaves appropriately, so as to reduce the excessive consumption of water and nutrients by the branches and leaves and restore root growth as soon as possible. At the same time, control watering and keep the pot soil slightly dry, so as to facilitate the rapid growth of root hairs and speed up the restoration of normal nutrient supply. At the same time, yew has a strong sprouting ability, especially strong new branch growth ability and is very tolerant of pruning; after surviving, it will soon 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 a better-quality product and do not use too much water at the same time) so that the root system can grow quickly and healthily. This allows the supply balance between roots and leaves to be restored as soon as possible, so that the yew grows well.
3. Because the nutrients in a potted yew bonsai are limited and can only provide about half a year of growth needs, or the current plant shape is relatively large and nutrient consumption is great, it is recommended that consumers replace the original pot as soon as possible after purchase. Because our company carries out a re-potting period of more than one month for the bonsai, and it is then stored for a period of time at the distribution company, and moreover yew likes fertile and loose soil. It is best to change the pot as soon as possible. When changing the pot, calculated by the inner diameter of the flower pot, the inner diameter of the new pot should be at least 5 cm larger. Carry it out before new buds sprout in February or March each year, and when the pot soil is neither dry nor wet, tip the tree and pot soil out together. Try not to break the original soil ball. If after survival the root system is found to be too much, the bad roots can be appropriately cut off, and the tree placed into the new pot, with nutrient soil filled around and pressed lightly and firmly. Only by making the soil in the pot closely contact the roots can the survival rate be improved; otherwise the plant is not easy to survive or does not grow vigorously. But the soil should not be pressed too firmly either; if too firm, the roots cannot breathe air, which will lead to root rot and plant death. After planting, water thoroughly at once. And place the pot in a cool place for a few days. After watering, the pot soil should not be turned or pressed again; otherwise the pot soil is prone to caking, or the soil is too firm and poorly aerated, which can easily cause root rot.
4. Fertilization method 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 and branches and leaves; phosphorus fertilizer can promote the formation of flowers and fruits; potassium fertilizer can promote the growth of stems and roots.
Because the bonsai is cultivated in the limited space of the pot and in limited cultivation soil, organic matter is decomposed by bacteria into inorganic salts and absorbed by the roots. With the consumption of yew growth, the nutrients in the pot soil gradually become insufficient, resulting in an inability to supply the needs of growth. Although prepared nutrient soil is used in the bonsai, do not fertilize within three months after purchase. Just water with about 1000 times diluted potassium dihydrogen phosphate solution or spray on the leaf surface 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 is thin and weak, the leaves are yellowish-white, "dry burnt edges" appear at the leaf margins and tips, and the leaves age prematurely and fall off, apply 1000 times diluted urea and 800 times diluted high-quality instant compound fertilizer solution of potassium sulfate, remove the sediment, and water the pot soil; apply about once a month. It is best to use fully decomposed dilute bean 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 a month. On the second day after fertilizing, water once more with clean water to dilute it in case the applied fertilizer 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 be mainly nitrogen and phosphorus fertilizer, and must not be too concentrated.
5. Watering method for bonsai: the principle is "do not water if not dry; when watering, water thoroughly."
Water is an important component of the flower and tree body. All life activities of flowers and trees are carried out with the participation of water. Whether photosynthesis or transpiration, none can do without water. Water can maintain the turgor pressure of cells, making the branches and leaves upright. But exceeding the limit will instead make the plant grow thin and weak. If the pot soil contains too much water for a long time, it will cause the leaves to turn yellow, leaf drop, root rot, and even death.
1. When the surface color of the pot soil becomes slightly lighter and the leaves are slightly curled, and when pressing the pot soil with a finger feels somewhat soft and loose, and when lightly tapping the upper middle part of the pot body with a finger joint produces a relatively dull sound, 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 produces a crisp "bang bang" sound, and the young shoots and young leaves wilt, the pot soil should be watered. Before watering, the cracks between the soil and the pot should be pressed firm with a hard object, then water with a large ladle; when pouring, the ladle should be close to the pot rim, pour the water in all 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 out quickly from the bottom of the pot, it means the soil and pot are not completely pressed firm; an object should be used to press tight the gap between the pot wall and the soil before watering. When the pot soil structure is normal, after watering it is better for water to seep out slowly 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 the time. When using tap water for watering, first place the water in sunlight for about three hours before watering, because light helps decompose the oxides in tap water and can raise the water temperature. Water can also be placed in a large basin for half a day or a night 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, water mist should also be sprayed on the leaf surface to keep the leaves 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, taking care not to miss watering or overwater.
2. Yew leaves are evergreen all year round and are suitable for placement indoors. But potted yew should not be placed at the air outlet of an air conditioner; otherwise it will increase the evaporation of water from yew leaves, easily causing rapid dehydration of yew branches and leaves, resulting in curled and dried leaves. 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 humidity, and place a basin of clean water indoors. If in a room with heating in northern winter, it should be kept away from the radiator, and a basin of clean water should be placed on the radiator to increase indoor air humidity. When the temperature in summer and autumn exceeds 30°C, shading and cooling work should be strengthened; 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 yew growth. And avoid rooms where direct afternoon sunlight from the west shines on the potted yew. In winter, the watering amount of the bonsai should be controlled to avoid the pot soil being too wet for a long time. Because plant growth is not vigorous in winter and the leaves volatilize less water, if the pot soil is too wet for a long time, the surface of the pot soil will cake and be impermeable, which can easily cause root rot. When raising yew indoors, be sure to pay attention to frequent indoor ventilation.
3. The soil for yew planting should be loose, rich in humus, fertile, and slightly acidic (PH=5.5-7). Do not pour tea water into the potted yew. If leftover tea water is often poured in, because the tea contains theophylline and other plant bases, it will change the soil pH and also have a relatively destructive effect on the organic nutrients in the soil. This inhibits yew growth and will cause excessive soil humidity, hinder pot soil aeration, and cause root rot and stem rot. If conditions permit, about once a week, move the potted yew 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 in the morning), which is beneficial to yew growth and improves disease resistance. In summer and autumn, prevent direct afternoon sunlight from the west from shining through the window directly 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, attention should be paid to regulating light. It needs light but should not be placed in strong light for too long. Generally, in summer and autumn, about two hours of sunlight before ten in the morning or after five in the afternoon 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 excessively dry indoor air.
2. If a new bonsai shows tender leaves that are dark yellow and lusterless, and the growing tip of the new shoot wilts, it is generally caused by watering too frequently and too much, causing the soil to cake and be impermeable, so that part of the root hairs rot and the ability to absorb water and fertilizer weakens. For mild symptoms, control the amount of watering, and use a hard and blunt object to gently loosen the surface soil of the pot so that the pot soil can breathe. 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 beneficial to the healthy recovery and growth of the root system. If the leaves yellow and curl within a short period, it indicates severe root rot; immediately turn over the pot to check the root rot condition (normal fibrous roots are tender, plump and white in shape). If more than half are affected, generally it cannot be saved.
3. Yellow leaves occurring from the bottom upward on old leaves, while new leaves generally grow normally, are generally caused by not watering thoroughly in one go, with too little water causing root water shortage. Sometimes the top leaves dry and curl, and dry leaves fall off at a touch, 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 firm the cracks at the pot rim with an object to prevent water from quickly leaking out through the cracks after watering. This creates the false appearance of thorough watering, and over time the roots will die from water shortage, causing the trunk to die. Move it outdoors at night 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 irrigated with relatively alkaline water for a long time, it will cause the leaves to turn from green to yellow, and even leaf drop. 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 that have yellowed due to 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 picked off to prevent the branch shape from being too dense and unventilated, which would cause the leaves to yellow or fall off. Thin out crossing branches, inward-growing branches and leggy branches, which can improve ventilation and light penetration and save excessive consumption of water and nutrients. When the 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 for topdressing nitrogen fertilizer, the concentration is generally 0.1%; if potassium dihydrogen phosphate is used alone for topdressing phosphorus fertilizer, the concentration used is 0.1% to 0.2%, with an interval of seven to ten days between topdressings.

Afforestation

Selection of Afforestation Site
Slopes in the middle and lower parts of hillsides, slope toes, Cao gullies, and shady slopes of mountain bays with a slope of less than 35 degrees, soil pH 4.5-7.0, and plots with high fertility, moisture and good drainage can all be used as afforestation sites. Artificial young forest land with a canopy density of no more than 0.4 can also be used for afforestation.
Site Preparation
Strip or pit site preparation. The pit specifications are 40 cm x 40 cm x 30 cm (length x width x height). According to different land conditions, fertilizer can be applied in combination with site preparation based on the land fertility situation.
Afforestation Density
1100 per mu. Plant and row spacing 60 x 400 cm (across the mountain x along the mountain). When afforesting in artificial young forest, its density should be determined according to the actual canopy density of the young forest; the principle is to plant in open spaces with good light conditions outside the crowns of the young trees.
Afforestation Time
Spring February-April, autumn September-November.
Management and Operation
After afforestation, tending should be carried out 2-3 times each year. Hoe tending twice in May-June and August-September, and knife tending in July. Starting from the second year after afforestation, combine topdressing with hoe tending each May. Starting from the fourth year after afforestation, raw materials can be harvested each year by pruning branches and leaves, or the whole plant can be dug out (including the root system) for extracting taxol. For landscaping, prune according to the shape requirements.

Pest and Disease Control

Yew stem rot is one of the most serious diseases harming yew cutting seedlings during the growing period. About 2 months after cutting, stem rot occurs successively at the stem base of the cutting seedlings (where the underground and aboveground parts of the cutting meet), spreading from individual diseased plants at first to entire clusters, causing the leaves of the cuttings to lose green, wither and die and fall off. Because this disease mainly occurs in the high-temperature seasons of summer and autumn, the cutting seedlings are damaged by high soil temperature, which provides conditions for pathogen invasion. The occurrence and prevalence of the disease mainly depend on the temperature in July-August; if the disease occurs earlier, the seedlings have weak heat resistance, and the disease is more severe.
Control Measures
1. Lower the surface soil temperature of the seedbed in summer and autumn to prevent scorching the stem base of the seedlings, so as to avoid wounds that lead to pathogen invasion;
2. Increase fertilizer application to promote the growth of cutting seedlings and enhance their disease resistance.
3. Use pentachloronitrobenzene powder + dexon powder mixed with water at a concentration of 5 g/kg for watering; its control effect is the best at 89%, or use carbendazim + thiophanate-methyl wettable powder mixed with water at a concentration of 4 g/kg for watering; its control effect reaches 83%.
4. For large-area control of this disease, alternate the above 2 methods, which can basically control the occurrence of stem rot in cutting seedlings.

7. Main Value

Economic Value

According to a report on page 5 of the People's Daily on October 17, 2001, in 2000 the price of high-quality taxol on the international market had reached as high as 180,000 US dollars per kilogram.
The heartwood is orange-red, the sapwood is light yellow-brown, the grain is straight, the texture is fine, the specific gravity is 0.55-0.76, it is solid and durable, and cracks little after drying. It can be used as timber for construction, vehicles, furniture, utensils, farm tools and stationery, etc.

Medicinal Value

The medicinal value of yew is mainly embodied in its extract - a secondary metabolic derivative - taxol. Taxol was first isolated from the bark of Taxus brevifolia as an anti-tumor active ingredient. It is one of the best drugs for treating metastatic ovarian cancer and breast cancer, and also has significant efficacy against lung cancer and esophageal cancer, and has obvious inhibition against nephritis and parvovirus inflammation.
The roots, stems and leaves of yew can all be used as medicine. They can treat difficult urination and relieve swelling and pain, and have therapeutic effects on: diabetes, female irregular menstruation, and increased blood volume. Yew can also be used for postpartum conditioning and has a certain therapeutic effect on female conditions.

Landscaping and Ecology

Landscaping
In landscaping and indoor bonsai, it also has very broad development prospects, such as high-end bonsai made from rare yew trees. The Taxus cuspidata (Japanese yew) bonsai treated with dwarfing techniques has a simple and elegant shape, with branches and leaves compact but not dense, spreading but not loose; red stems, red branches, green leaves and red berries give it multiple ornamental values of stem appreciation, branch appreciation, leaf appreciation and fruit appreciation.
Air Purification
Yew can purify indoor air very well, and can absorb indoor toxic gases such as formaldehyde from new house decoration very well, thus reducing the content of toxic gases indoors. Yew itself can absorb carbon dioxide and release oxygen, making it a natural oxygen bar that can be used both day and night. It belongs to the CAM category of tree species and can prevent respiratory diseases and maintain the cleanliness and safety of the air. Modern environmental monitoring has proven that yew can absorb many toxic gases such as sulfur dioxide and carbon monoxide into its body, purifying indoor air.