Rhododendron - Beauty in Flowers
The scientific name of azalea is Rhododendron simsii amp; R.spp. Also known as azalea, mountain pomegranate, mountain azalea, red azalea, mountain azalea Rhododendron, etc.; belongs to the Rhododendron family and is one of the top ten famous flowers in China.
Among all ornamental flowers and trees, it can be said to have both beautiful flowers and leaves. It is suitable for both ground planting and potted plants. The most versatile one is the azalea. Bai Juyi praised it and said: "Two branches are broken off and held in the hand. If you look closely, they don't look like they exist in the world. The thing in the flower is Xishi, and the hibiscus and peony are all from the mother." Among the natural distribution of rhododendrons in the world, there are many types and huge quantities, none of which can match China. China is the treasure house of rhododendron resources in the world! Today, Jiangxi, Anhui, and Guizhou regard rhododendron as the provincial flower and the city flower. There are as many as seven or eight cities in the country, which shows people's love for azaleas. Azalea is a large genus with more than 900 species in the world, distributed in Europe, Asia and North America. Asia has the most, with 850 species, of which there are more than 530 species in my country, accounting for 59% of the world's species, which is particularly concentrated. Located in the Hengduan Mountains in the three provinces of Yunnan, Tibet and Sichuan, it is the birthplace and distribution center of rhododendrons in the world.
Bhutan, Sikkim, Nepal, Myanmar, and northern India in the Himalayas also have many species, while Japan, North Korea, Soviet Siberia, and the Caucasus have only a few species. In addition, there are about 280 species in the New Guinea-Malaysia region, which is the secondary distribution center of rhododendrons. Among them, there are more than 160 species in New Guinea, more than 100 species in Indonesia, and 10-20 species in the Philippines, Vietnam and the Malay Peninsula. Since this area is a tropical island mountain with a humid climate, almost all the azaleas produced are epiphytic shrubs. The seeds have strange filamentous long tail-like appendages that form a special type of tropical alpine. There are only 24 species in North America, distributed on both sides of the Atlantic and Pacific coasts of the United States, as well as Canada, Alaska and Greenland. There are even fewer in Europe, with only 9 species, and a few species are distributed around the Arctic. There is only one species in Oceania, which is distributed in Queensland, northern Australia. It is also a tropical alpine type.
The distribution of aldocks in my country has been basically clear through surveys and studies by modern botanists. There are more species in the south of the Yangtze River, but few in the north of the Yangtze River; the most species are in Yunnan, followed by Tibet, and Sichuan. The further away from this center, the fewer the varieties. Xinjiang and Ningxia are arid desert areas and have no natural distribution. The number of rhododendron species in each province (region) is roughly as follows: 257 species in Yunnan, 174 species in Tibet, 152 species in Sichuan, 75 species in Guangxi, 35 species in Guangdong, 43 species in Guizhou, 37 species in Hunan, 35 species in Fujian, 30 species in Taiwan, 27 species in Jiangxi, 27 species in Hubei, 18 species in Zhejiang, 15 species in Gansu, 13 species in Shaanxi, 13 species in Qinghai, 9 species in Anwei, 5 species in Jilin, 4 species in Jiangsu, 4 species in Liaoning, 4 species in Heilongjiang, 3 species in Inner Mongolia, 2 species in Shandong, and Henan , Hebei, and Shanxi each have 1 species. Vertically distributed, up to 4500-5000 meters above sea level.
Rhododendrons have different morphological characteristics in different natural environments, and the differences are very different. There are large evergreen trees, small trees, evergreen shrubs, and deciduous shrubs. Some have thick trunks, up to more than 20 meters tall. Rice, some are creeping, cushion-shaped or epiphytic types, only 10-20 cm high. The basic form is: the trunk is upright, solitary or clustered; the branches are alternate or false whorled.
The branches and leaves are hairy or not, and the branches, leaves and pedicels have scales or not; the leaves are multi-shaped, but not strip-shaped, with entire margin, rarely with fine serrations, leathery or papery, Evergreen, semi-evergreen or deciduous, with or without fragrance; flowers terminal, lateral or axillary, single flower, few flowers or more than 20 flowers integrated into racemose umbels, blooming before or after the leaves, with conspicuous corolla. Funnel-shaped, bell-shaped, radiating shank-shaped, bell-shaped, dish-shaped to bowl-shaped or tube-shaped, with 4-5 lobes, and some with 6-10 lobes; colorful flowers; dark spots or light halos on the throat ; Nectaries are present at the base or not; fragrant or tasteless; flowers are cup-shaped, 4-5 lobed, persistent; 5-10 stamens, rarely 10-25, unequal length, filaments hairy or absent, Carrying medicine, the top hole is cracked, the ovary is superior, 5-10 cells, the style and ovary are hairy or not, with or without glands; the gourd has 5-10 petals, many seeds, mostly powdery or chaffy shape. Original species classification: The whole genus is divided into 5 subgenus and 8 groups, 3 of which are further divided into 58 subgroups, and the groups are species. Namely:
1. Evergreen scaleless rhododendron subgenus 1. The evergreen scaleless rhododendron group is divided into 24 subgroups.
2. Evergreen scaly Rhododendron subgenus 1. The evergreen scaly rhododendron group is divided into 27 subgroups. 2. Bearded Rhododendron Group 3. Cranberry and Rhododendron Group The following are divided into 7 subgroups.
3. There is only one species of the subgenus Ovis in my country.
IV. Subgenus Azalea 1. Short calyx group 2. Azalea group
5. Subgenus Azalea 1. Ma Yinhua Group 2. Rhododendron group
The above three subgenera are customarily called evergreen rhododendrons, and the three and four subgenus are called deciduous rhododendrons.
Here are several evergreen azaleas introduced below:
Lantana azalea: also known as lantana, horse nose tassel, oxblood flower, dog blood flower, red camellia, dense Bucket flower. Evergreen shrub to tree, with a height of 2-15 meters and a diameter at breast height of 40 cm. The bark is grey-brown, maggot-thick, and peels off in irregular sheets. The leaves are leathery, oblong-lanceolate, and the back is densely covered with gray-white to brown spongy thin hairs. The flowering period is from February to May, with terminal spherical umbels with 10-20 flowers. The corolla is bell-shaped, 3.5-5 cm long, fleshy, deep rose red, with 10 stamens and 10-chambered ovary. The fruit is ripe from October to November. Produced in Yunnan, Guizhou, Guangxi and other provinces and regions, it is also distributed in Myanmar.
Azalea of ??Yunjin: also known as Tianmu Rhododendron and Yunjin Flower. Evergreen shrub, 2-4 meters high, with thick light green branchlets. The leaves are thick and leathery, oblong to oblong-elliptical or obovate, with dark green leaves, light green backs, and hairless leaves. The flowering period is in May. There are terminal racemose umbels with 6-12 flowers. They are fragrant. The corolla is funnel-shaped and bell-shaped, 4-5 cm long, 7-9 cm in diameter, pale pink, with 7 lobes, round and one-dimensional. There are 14 stamens and 10-chambered ovary. There are glands on the pedicel, flowers, corolla base, ovary and style. The fruit is ripe from October to November. There are many seeds, shaped like chaff. It is produced in mountain forests at an altitude of 600-2000 meters in Zhejiang, Anhui, Jiangxi, Fujian, Guangdong, Guangxi, Hunan, Sichuan and other places. In recent years, it has been successfully introduced into gardens in Kangzhou, Wuxi, Shanghai and other places.
Big Tree Rhododendron: Also known as Big Mountain Dog Whole Flower. A large evergreen tree, up to 25 meters high, with a diameter at breast height of 60 to 0 centimeters, and a maximum base diameter of 3 meters. The bark is light dark brown, peeling off in sheets; the branchlets are thick and covered with light gray felt. The leaves are leathery, oblong to oblanceolate, 24-34 cm long, with a blunt tip and a wide wedge-shaped base. The surface is dark green and the underside is light green. Terminal racemose umbels bloom from February to March, with 24 flowers. The corolla is bell-shaped, 5.5-8 cm long, 6-8 cm in diameter, water red, with 8 lobes, round, and 8 nectars at the base. Glandular sac, 16 stamens, 16-chambered ovary, densely covered with tomentose. The fruiting period is from October to November. Produced in the mountainous evergreen broad-leaved monsoon forest at an altitude of 2400-2600 meters in Gaoligong Mountain, Tengchong County, Yunnan Province. It was first collected by the British man G Forresst at the head of the Tengchong River in 1915. The saw diameter is 2.6 meters and the annual rings are 280 years old. The wood disc is now in the British Museum in London. It was announced as a new species in 1926 and had not been found in China for a long time. It was not until 1983 that Professor Feng Guoliu and others rediscovered it in Tengchong, and a large tree with a base diameter of 3.07 meters was found the following year.
This is the tallest rhododendron tree in the world and is known as the "King of Rhododendrons".
Ma Yinhua: also known as egg-leaf azalea and Qingming flower. Evergreen shrub, 2-4 meters high. The leaves are leathery, broadly ovate, 3-3.5 cm long, the apex is sharp to blunt, with a convex tip, and the base is rounded. The flowering period is from March to May. The flowers are solitary in the leaf axils, pink, rose red, lavender or purple-white, with 5 lobes, 3 cm in diameter, pubescent throat, 5 stamens, and 5-chambered ovary. The fruiting period is from August to October. Produced in Jiangsu, Zhejiang, Anhui, Jiangxi, Hubei, Hunan, Fujian, Guangdong, Guangxi, Sichuan, Guizhou and other provinces and regions, at an altitude of 500-1200 meters, under sparse forests or in ravines and shrubs in the shade of hillsides. Horticultural varieties There are currently about 200 to 300 horticultural varieties widely cultivated in my country. Because their main lineage is azalea, although they do not lose their leaves in winter, they are still classified as deciduous azaleas. According to the morphology, traits, parents and origin, it is divided into 4 types: Eastern cuckoo, hairy cuckoo, western cuckoo and summer cuckoo.
Eastern cuckoo: It is the Eastern cuckoo, because it comes from Japan. Also known as Shiyan, cinnabar azalea, spring azalea, etc. This category includes Shiyan Rhododendron and its varieties, with many varieties. Its main characteristics: It is short in size, 1-2 meters high, with scattered branches, pale leaves, and few shiny hairs. It blooms in April with dense flowers. The flowers are the smallest, generally 2-4 cm in diameter, and the largest is 6 cm. , single petal or calyx petals formed into sleeve petals, rarely double petals, and various flower colors. Traditional varieties include 'Xintiandi', 'Xueyue', 'Bizhi', 'Sunrise', and 'Four Seasons Reputation' which can bloom twice in spring and autumn, etc.
Rhododendron: Commonly known as hairy-leaf azalea, big-leaf azalea, spring azalea, etc. This category includes Splendid Rhododendron, Hairy Rhododendron and their variants and hybrids. They are tall, up to 2-3 meters tall, strong in growth, strong in adaptability, and can be planted in the open field. They are excellent rootstocks for splicing azaleas. Young branches are densely covered with brown bristles. The leaves are up to 10 cm long, rough and hairy. The flowers are large, single-petaled, broadly funnel-shaped, rarely double-petaled, and come in red, purple, pink, white and multiple colors. There are more than 10 varieties, and the most cultivated ones are 'Jade Butterfly', 'Purple Butterfly', 'Ryukyu Red', 'Yu Ling', etc.
Western cuckoo: It was first bred in the Netherlands and Belgium in Western Europe, so it is called Western cuckoo, or Western cuckoo for short. It is a result of repeated hybridization of Gaoyue azalea, azalea, and hairy white azalea. It has the largest number of flower colors and flower types. , the most beautiful kind. Its main characteristics are short and stocky body, tight crown, delicate habits, and afraid of sun and cold. The leaves are thick, dark green, with few hairs, and the leaf shapes can be divided into light leaves, pointed leaves, twisted leaves, long leaves and broad leaves. The flowering period is from April to May, and the flowers are of various colors, including single color, flying white, bordered, reddish, bright spots, sandblasting, brocade, etc. Most of them are double and compound, and few are single. The flowers are long, narrow and round. Castrated, flat, turned back, wavy, flying, ruffled, curled, etc., diameter 6-8 cm, size can exceed 10 cm, traditional varieties include 'Crown', 'Jinpao', 'Tiannuwu', ' Sihaibo' and so on, a large number of new hybrid varieties have appeared in recent years.
Summer cuckoo: native to India and Japan. In Japan, it is called Satsuki cuckoo. It sprouts branches first and blooms the latest, usually from late May to June, hence the name. The main characteristics are slender branches and leaves, dense branches, plump and neat crown, about 1 meter high. The leaves are narrow and closely arranged. The flowers are wide and funnel-shaped, with a diameter of 6-8 cm. The colors and petals are as rich and varied as those of the azalea. The flowers have single, double or double petals. They are a good material for making landscapes. Traditional varieties include 'Changhua', 'Dahongpao', 'Chenjia Yinhong', 'Wubao Lvzhu', 'Zichendian', etc. Among them, 'Wubao Green Pearl' has a small flower in the shape of a pavilion, which is the most double-petaled type among azaleas.
The main producing area of ??rhododendrons in my country is the Hengduan Mountains in the three provinces of Yunnan, Tibet, and Sichuan. Its complex topography and topography constitute a special climate, with extremely uneven rainfall distribution. It is dry in winter and spring and rainy in summer and autumn. The vertical distribution is obvious. In the low and flat valleys between 1000 and 2000 meters, there are Rhododendron acuminata and Rhododendron axillaris, etc. At 2000-2800 meters, the climate is warm and cool, and there are Rhododendron lucidum, Rhododendron rhododendron, Yunnan Rhododendron, Rhododendron axillaris, etc.
The sunny slope of the valley at 2800-4000 meters is a mixed forest of evergreen broad-leaved and broad-leaved broad-leaf. On the forest edge or grass slope, it is densely composed of yellow cup azalea, white snow azalea, tufted azalea, woolly rhododendron, prairie azalea, etc. The inaccessible Rhododendron Forest or Hong Kong Cluster has the largest variety of Rhododendrons. The flowering period is from April to July. They are colorful and as bright as brocade. Sometimes they can cover the entire mountain top up to 10 to 20 square kilometers. The area of ??4000-4500 meters is full of trees and shrubs. Very rarely, polytechnic azaleas, procumbent azaleas, and golden azaleas with a height of 10 to 20 centimeters become cushion plants and multiply in gravel graveyards or flowstone beaches. There are no rhododendrons above 4,500 meters. Alpine evergreen rhododendrons have long grown in humid and cool high-altitude mountainous areas. The introduction must create similar environmental conditions, such as no water on the ground, soil pH 5-6, good permeability, rich in organic matter, and the ability to cover sprouts and spray. Water, cooling and other equipment.
Azalea is the representative of deciduous azalea and is the most widely distributed, ranging from Henan and Shandong in the north, to the Pearl River Basin in the south, to Fujian and Taiwan in the east, to Sichuan and Yunnan and Guizhou in the west, in high mountains, low hills, shady and sunny slopes There are traces of it in mountains, valleys, rocks, forest edges, and grass and shrubs. Jiangnan flowers bloom in March-April, and it is a brilliant red. The mountain people used it as firewood and cut it repeatedly, which shows its adaptability and vitality. In the past, transplantation was difficult to survive, which was related to the lack of re-pruning. Although horticultural varieties have been artificially improved, they still reflect the basic habits of the original species, which are cold-tolerant and heat-resistant, and require fertile, acidic, loose and transparent soil. Some rhododendrons have a very long life span. For example, there is a big tree rhododendron in Yunnan that is more than 500 years old, and there is a beautiful rhododendron that has been planted in the open field in Wuxi for more than 50 years.
1. Sowing: Rhododendron has high fruiting bunches, many seeds, and a high germination rate. The seeds can produce a large number of offspring, and the seedlings have strong plasticity and vitality. They are an important means of introduction and breeding.
1. Seed collection: Harvest the gourds in autumn when they turn green-brown or yellow-brown, place them indoors to dry, wait until they crack, shake out the seeds, and store them in a dry place indoors. Sow in the following spring.
2. Sowing: Use shallow pots, wooden boxes or in the ground bed, lay the bottom with well-drained coarse-grained soil, and use orchid mud or leaf mold soil for the top layer of 2 cm (both need to be disinfected). After the seeds are evenly removed, cover them with a thin layer of fine soil. Or add 0.5-1 cm of crushed sphagnum moss on the orchid mud, and sow the seeds directly into the sphagnum moss without covering it. Then add water to moisten the pot soil, cover it with a film or glass plate, and place it in a shaded place.
3. Management: Before seedlings emerge, keep the pot soil moist. Generally, at 15-20°C, seedlings will emerge in about 20 days, with a germination rate of 75-85%. After that, the covering can be removed, and attention should be paid to ventilation to improve the resistance of the seedlings. When dry, use a spray nozzle to spray moisture, and do not wash away the seedlings.
4. Split seedlings: Deciduous azaleas grow quickly. They can be transplanted for the first time when they have 2-3 true leaves. The spacing between plants is 2-3 cm. After autumn, when they grow to 2-3 cm high, dig them up again and transplant them into 3-inch small pots, 3 plants per pot. In the second year, the seeds will be divided into seeds depending on the growth conditions. Flowers will usually appear in 3-4 years. Evergreen azaleas are transplanted for the first time in autumn and again in the following autumn. During the seedling stage, strong light, heavy rain, and strong winds need to be avoided. The soil should not be too wet, and watering and spraying are still allowed.
2. Cutting: It is the most widely used method. It has the advantages of easy operation, high survival rate, rapid growth and stable traits.
1. Cuttings: Take the young and lignified branches of the current year, break them off at the heel, trim the hairs, cut off the lower leaves, and leave 4-5 leaves on the top. If the branches are too long, they can be cut off Top tip. If it cannot be picked and inserted at will, the base can be wrapped with wet cloth or moss, covered with plastic film, and placed in a shaded place where it can be stored for several days.
2. Time: In the south of the Yangtze River, cuttings are taken before the mildew season, with the highest survival rate. The west cuckoo is from late May to early June, the hairy cuckoo is from early to mid-June, and the east cuckoo and summer cuckoo are in Mid to late June. At this time, the cuttings are moderately old and tender, the weather is warm and humid, and the survival rate is over 90%.
3. Method: A small amount can be inserted in the pot, and a large amount can be inserted in the bed. The medium can be orchid mud, Huangshan soil, river sand or hard rock, perlite, etc. It is required to have few pathogens, no weeds, and no fertilizers. Insert 1/3 to 1/2 of the cuttings, spray them with a fine-hole pot and place them under a shade shed. The bottom of the basin needs to be raised by one brick; the depth of the planting bed is 20 cm, and the bottom of the bed is filled with a 7-8 cm thick drainage layer to facilitate drainage.
4. Management: Within one month after cutting, focus on shading and spraying water to keep the cuttings fresh. Avoid the impact of rain during heavy rains. Pay attention to drainage when it rains for consecutive days. Spray 1/1000 thiophanate to prevent black spot. In high-temperature seasons, increase water spraying on the ground and leaves, and pay attention to ventilation and cooling. The hairy cuckoo, eastern cuckoo and summer cuckoo take root quickly, about 1 month; the western cuckoo takes 60-70 days. After the roots grow, the top ends and if flower buds form, they should be removed. Reduce shading after September to make the seedlings gradually strong, and apply light fertilizer in October. It can be potted in the second half of the year. If an automatic spray device for electronic leaf leaves is installed on the planting bed and the medium is stone or perlite, then shading is not required. Under full sunlight, roots will take root in more than 20 days, with a survival rate of over 95% and transplantation in 2 months.
Grafting: It is often used when breeding cuckoos. Its advantages are: the scion only requires a section of young shoot; the young shoot can be grafted at any time without restriction; several varieties can be grafted on the same plant; it grows faster than cuttings and has a high survival rate. There are many grafting methods, the most commonly used is split grafting at the top of young shoots. The best time is May to June, with a survival rate of 90%.
1. Rootstock: Choose a 2-year-old solitary cuckoo, and the new shoots should be similar in thickness to the scion. The best species of rhododendron are 'Jade Butterfly' and 'Purple Butterfly'. The original species of rhododendron are generally not used.
2.Scion: Cut 3-4 cm from the mother plant of cuckoo. To grow young shoots, remove the lower leaves, leaving 3-4 leaflets at the top, and cut the base into a wedge shape, and the cut surface is 0.5-1 cm long.
3. Method: Cut off 2-3 cm of the new shoot of the current year, remove the leaves, cut 1 cm lengthwise, insert the scion, align the cortex, tie with plastic film tape, and connect the joint with the scion Put it into a plastic film bag and tie the mouth of the bag tightly.
4. Management: Place under a shade shed and avoid direct sunlight. Pay attention to whether there are water droplets in the bag. If not, untie the scion and re-tie it to wet the scion. If the scion does not wilt for 7 days, you are sure of success. Remove the bag after 2 months and untie the binding in the next spring.
5. Site: Cultivation of cuckoo requires both indoor and outdoor environments: indoors are used to prevent cold in winter, and the coldest temperature is not lower than -2-3℃. In order to survive the hot summer, they are kept outdoors from mid-April to early November in the Jiangnan area, which requires natural shade from deciduous trees or artificial shade sheds to create a semi-shady and cool growing environment. The ground should have a drainage slope, and the pots should be placed on shelves.
6. Selection of pots: In production, clay pots with good permeability and low price are used. Rhododendrons have shallow roots and slow expansion. Try to use small pots for cultivation to avoid watering out of control and hindering growth. Regarding plant age and pot size, please refer to the following table: 1-2 years old: use 3-inch pots; 3-4 years old: use 4-inch pots; 5-7 years old: use 5-inch pots; 8-10 years old: use 6-inch pots 11-15 years old: use 7-8 inch pots; 16-20 years old: use 9-inch pots; 20 years and above: use 10-inch pots.
7. Soil used: Black mountain soil (orchid mud) is commonly used, preferably black in color and light in quality. When using, spread it out and expose it for several days, pick out the debris, sift out the thickness, and pot it in layers to ensure that the water is flowing smoothly. In addition, peat soil, Huangshan soil, leaf humus soil, pine needle soil, or even mixed soil made of cinders, sawdust, etc. can be used as long as the pH is between 5.5-7, is well drained, and is rich in humus.
8. Potting: This is usually done when leaving the house in spring or when entering the house in autumn. Fill the bottom of the pot with a drainage layer of coarse-grained soil. After potting, place it in a bright place for a few days, and then move it to a suitable location. Location. During the seedling stage, the pots need to be changed more frequently, once every 2-3 years. After 10 years, it can be replaced every 3-5 years. As long as there are no problems with the old tree, it can last for many years without replacement.
9. Watering: It should be flexibly controlled according to weather conditions, plant size, pot soil dryness and wetness, and growth and development needs. The water quality should be alkaline-free and clean. If you use tap water to water the flowers, it is best to store them in the tank for 1-2 days. The water temperature should be close to the temperature of the pot soil. After November, the temperature drops, the growth is slow, and the water requirement is small. When the room is not heated, it is not a problem not to water for 3-5 days; in late February, the growth gradually increases, and the amount of water should be appropriately increased; from March to June, flowering and shoot shoots will occur. The water needs is large, once a day on sunny days, and if it is insufficient, water must be replenished at night; in the rainy season, if it rains for days, water must be poured into the side basin in time.
During the high temperature season from July to August, water should be watered as dry as possible. Water should be sprayed on the ground and leaves at noon and evening to cool down and increase humidity. The weather is still hot in September and October, so watering should not be neglected.
10. Fertilization: West cuckoo requires thin fertilizer applied frequently. Commonly used fertilizers are grass juice water, fishy water, and rapeseed cake. Grass juice is made from retting young leaves and leaves. It is the best nitrogen fertilizer and can be used as water. The fishy water consists of fish offal, heads and tails, smelly fish and rotten shrimps, etc. Add water 10 times, store it in a tank, seal it and ferment it for more than half a year. When using, take the original solution and add water, and apply it at a concentration of 3-5%. This fertilizer is rich in phosphorus, which can make the leaves bright and the flowers colorful, but it should be rinsed with clean water once the next day. Rapeseed cake is a comprehensive fertilizer, which also needs to be crushed and retting for several months before being applied with water.
11. Shade: The cuckoo must be shaded from May to November. The height of the shed is about 2 meters, and the light transmittance of the reed curtain is 20-30%. A curtain should also be hung on the west side to shade it every day. Shade time: May 9:00-15:00, June 8:30-16:30, July-August 8:30-17:00 in the southeast corner in the morning, curtains in the southwest corner in the afternoon September 8:00 -16:00, 9:00-15:30 in October, and noon in November. Cover the curtains appropriately. Do not cover the curtains after the middle and late days. If you need to delay the flowering period from December to April, cover the curtains. In this way, the cuckoo can bloom as late as late April and reach its peak on May Day
12. Pruning: In order to speed up the formation of skeletons of seedlings within 2-4 years, the flower buds are often removed, or the new ones are pruned. Pinch the tips when they reach 4-5 cm in length to promote the germination of side branches. Some varieties have short and numerous new shoots, so they should not be topping but should be thinned appropriately. The 5-10-year-old seedlings should not bloom too much, and some flower buds should be removed. After it grows into a large tree, it is mainly necessary to prune diseased branches, weak branches and branches with disordered tree shape, mainly using sulfur pruning.
13. Flowering period management: When the azalea blooms, place it indoors, away from the sun and rain, and it can last for 1 month. If indoor ventilation is poor, it should not be left for a long time and should be replaced in one or two weeks. The buds of the cuckoo bloom between July and August. They enter the house after autumn and maintain the temperature at 20°C. They will bloom after half a month. According to this, it can bloom on New Year's Day and Spring Festival. If it has been kept in a cold room with a low temperature of 3-4℃ and taken out in mid-September, it will bloom during the National Day. After flowering, the remaining flowers should be removed promptly, pruned, and properly maintained.
14. Pest control: The most common pests are red spider mites and armyworms. Spider mites cause serious damage when the temperature is high and dry from June to August, often causing the leaves to turn yellow and fall off. They can be sprayed with 1/1000 trichloride, once a week, 3 times in a row. The armyworm is harmful from May to October and spreads faster in dry climate. It can be sprayed with 1/1500 dimethoate or dichlorvos. Brown spot is the most common disease. It mainly occurs in the mildew season. Brown patches appear on the leaves, causing cyclic infection and causing great harm. It is the main cause of defoliation. The control method is: spray 1/800 before and after flowering. thiophanate or an equal amount of Bordeaux mixture, pay attention to improving lighting conditions, strengthening ventilation, and burning diseased leaves at any time. Artificial pollination hybridization is a conventional breeding method. Varieties with well-developed pistils and high fruiting rates should be selected as female parents, and pollen should be collected from varieties with special ornamental value in flower color and pattern. Pollen can be refrigerated in ice bottles for long-distance transport. Pollination should be done when the stick is secreting mucus. In order to improve the success rate, pollination should be repeated 2-3 times. Since the self-pollination strings are very low, there is no need to emasculate them in advance. In cold climates and without insect interference, bagging is not required.
After the seeds are sown, the deciduous azaleas will bloom after 3 years. They need to be screened, and then cultivated for 2-3 years. If the characteristics are stable, they will be screened again, and only a few percent will be ideal. Hybridization, screening, and cultivation are long-term tasks. In terms of horticultural varieties in China, there are hundreds of new varieties obtained from hybridization, with rich colors and patterns. But the growth and development process of evergreen rhododendrons is longer, and cross-breeding work has just begun. Horticultural varieties themselves are a complex of multiple genes, and various variations often occur in flower color and flower shape. New varieties can also be obtained by utilizing the budding phenomenon of branches, such as 'Qingnv', 'Xinhong', ' Rhododendrons such as "Feng Lai" and "Qiu Shuibao" are all selected from buds and are excellent bonsai materials.
It has the advantages of slender branches and leaves, evergreen all year round, resistant to cutting, strong germination, unique root structure, few pests and diseases, colorful flowers, and long life. It can be dried straight by methods such as bending branches, braiding, cutting, and lifting roots. , curved trunks, double trunks, multiple trunks, jungles, roots, cliffs, lifting roots, stone attachments and other artistic shapes can be made into tree stump bonsai with beautiful shapes, branches, leaves and flowers.
In addition to potted ornamental plants, rhododendrons, eastern cuckoos, and summer cuckoos can all be used for courtyard decoration, ranging from small ones on patios and corners, to large ones such as forested hillsides, creekside roadsides, and lawn stones. Planting in clumps or patches along the bank can form a beautiful landscape. Rhododendrons can also be used to form green barriers and pavements in flower tubes. They are blooming in spring and evening, dense and green in summer, and have colored leaves in autumn and winter, so they can be enjoyed in all seasons.
In addition, azaleas also have edible and medicinal values. The flowers of azalea are sour and non-toxic and can be eaten raw; the flowers of large white azalea and rough-stemmed azalea are still beautiful vegetables for the people in central Yunnan; soaking and retting the branches, leaves and flowers of sheep's legs can be used as insecticides; Xing'an azalea etc., can make medicine. The bark and leaves of some types of trees are rich in dipping substances, which can be used to extract gum; the wood and roots of azaleas are fine and tough in texture, and can be used to make bowls, chopsticks, pots, bowls, pipes, roots and other daily crafts and arts. .