azalea

[Edit this paragraph] Basic information

Names in the household registration book

Rhododendron: Beauty lies in flowers.

Scientific name/Latin name: Rhododendron II & Simms；; Staphylococca rubra

(Rhododendron-subgenus Cynanchum,

Rhododendron Titsushi subgenus).

British name: Indian azaleas, azaleas

Alias: Yingshanhong, Shan Shiliu, Yamagata, Yamagata, Jindalai, Shanjuan, Rhododendron, Yanshanhong, Yanshan Flower, Qingming Flower, Gesanghua (Tibetan), Jindalai (Korean), Shan Shiliu, etc.

Classification of families and genera:

Field: the plant kingdom in the plant kingdom

Door: angiosperm magnolia door

Class: Subclass Dicotyledonous Magnolia

Objective: Ericaceae Ericaceae Ericaceae.

Family: Ericaceae

Genus: Rhododendron

Species: Rhododendron pentaphyllum

R. month and month

[Edit this paragraph] Introduction

Rhododendron: one of the top ten famous flowers in China. Among all ornamental flowers and trees, it can be said that flowers and leaves are beautiful, suitable for ground planting and potted plants, and are most widely used. Bai Juyi praised: "When I am at leisure, I have two branches in my hand. If I look closely, it doesn't look like anything in the world. This thing in the flower is a stone, and the peony is a whip. " In the natural distribution of rhododendrons in the world, there are so many kinds and quantities that no one in China can match them. China is the treasure house of azaleas in the world! Today, as many as seven or eight cities in Jiangxi, Anhui, Guizhou and other places regard azaleas as provincial flowers and designate them as city flowers, which shows that people love azaleas deeply. When azaleas are in full bloom, it is the time when azaleas are singing. The ancients left many poems and beautiful legends, and there was a custom of taking flowers as festivals. Rhododendrons are mostly shrubs or small trees, and have their own living habits and forms because of different ecological environments. The smallest plant is only a few centimeters high, cushion-shaped, and lives close to the ground. The largest is as high as tens of feet, standing tall and spectacular.

Rhododendron (Ericaceae) is a kind of woody plants with beautiful flowers and leaves. Rhododendron is an extremely diverse genus, including about 800 species. It is mainly native to the northern temperate zone, especially in the mountainous areas of Himalayas, Southeast Asia and Malaysia, where moist and acidic soil forms dense bushes. This genus includes rhododendron species, which some gardeners think is another genus.

The habits of rhododendrons vary from evergreen to deciduous, from low ground cover plants to tall trees. Upland cotton was first cultivated for garden viewing in the middle of 1 7th century, and its height can reach1m (3 feet). Other species range from mat-like dwarfing species with a height of only 65,438+00 cm (4 inches) to trees with a height of more than 65,438+02 meters. The former is the weeping wood native to Yunnan, China, and the latter is the Asian weeping wood, hairy weeping wood and big weeping wood native to Asia. Except rhododendron species, the leaves are thick, leathery and evergreen; Flowers are usually tubular to funnel-shaped and vary greatly in color, including white, yellow, pink, crimson, purple and blue.

There are a large number of rhododendrons (R. catawbiense) in the southeastern United States, and the June flower season is the scenic spot of Great Smoky Mountain National Park. The hybrid azaleas with willow leaves and related varieties can produce robust Kataba hybrid azaleas. Rhododendron willow (R. maximum) and Rhododendron willow have overlapping distribution areas and are more northeast, so they are often cultivated and ornamental. Both can grow into small trees over 6 meters. Rhododendron canadensis (R. canadense) is native to the northeast of North America, and it blooms rose-purple flowers before the leaves are unfolded.

[Edit this paragraph] Distribution of origin

China is the distribution center of rhododendron, with about 530 species distributed in all provinces except Xinjiang and Ningxia. Southeast Tibet, southwest Sichuan and northwest Yunnan are the most concentrated producing areas, with more than 100 species respectively, and Yunnan alone accounts for more than half of the rhododendron species in China. Many countries in the world are imported from here.

Rhododendron is a big genus, with more than 900 species in the world, distributed in Europe, Asia and North America. Among them, there are 850 species in Asia and more than 530 species in China, accounting for 59% of the world, especially in Hengduan Mountain area of Yunnan, Tibet and Sichuan provinces. It is the birthplace and distribution center of rhododendron in the world. There are many species in Bhutan, Sikkim, Nepal, Myanmar and northern India in the Himalayas, but there are few species in Japan, Korea, Siberia and Caucasus.

[Edit this paragraph] Morphological characteristics

Rhododendron has many kinds and different shapes. From big trees (more than 20m in height) to small shrubs (only 10 cm-20 cm in height), the trunk is erect or creeping, and the branches alternate or alternate. It is distributed in Europe, Asia and North America, and Asia is the largest. It is different from the western azalea in that its body is relatively short and its flower shape is relatively small.

[Edit this paragraph] Ecological habits

All provinces and regions in China except Xinjiang are distributed, especially Yunnan, Tibet and Sichuan are the world distribution centers of rhododendrons. There are many kinds of rhododendrons with different habits, but most of them are produced in high altitude areas, and they like cool and humid climate and hate hot and dry. It is required that the soil is rich in humus, loose, moist and acidic, and the pH value is between 5.5 and 6.5. Some species and horticultural varieties have strong adaptability, drought tolerance and barren tolerance, and can grow in the soil pH value of 7-8. But in the soil with poor viscosity or permeability, the growth is not good. Rhododendron has certain requirements for light, but it is not resistant to exposure. In summer and autumn, deciduous trees or shade sheds should be used to keep out the scorching sun, and the ground should be sprayed with water frequently. Rhododendron shoots in spring and autumn, mainly in spring. The optimum growth temperature is 15 ~ 20℃, and the growth stops when the temperature exceeds 30℃ or below 5℃. There is a short dormant period in winter, and then with the increase of temperature, the flower buds gradually expand. Generally, it blooms in the open field from March to May, and it blooms in high altitude areas as late as July and August. Greenhouse cultivation is in the north. 65438 can bloom from 0 to February. Rhododendron is resistant to pruning, and its hidden buds are easy to germinate after being stimulated, which can be used to control the tree shape and revitalize the tree. Pruning is usually carried out before May, and new branches can form buds in the same year. If it is too late, it will affect flowering. Generally speaking, new buds that germinate around early autumn can still be lignified. If the new buds form too late, they are vulnerable to freezing injury in winter. Evergreen or deciduous shrubs.

[Edit this paragraph] Common categories

The varieties often cultivated in China are: Mao Juan, Xia Juan, Xiyangjuan, Dong Juan, Chunjuan, Carya cathayensis, Rhododendron Hong Ying, Mayflower and Rhododendron Yunyin.

There are about 900 species of rhododendrons and about 850 species in Asia. There are about 530 species in China, which are distributed in all communities except Xinjiang. There are about 280 species in New Guinea and Malaysia, almost all of which are epiphytes. In addition, there are 24 species in North America, 9 species in Europe and 1 species in Oceania. There are many kinds of rhododendrons, which vary greatly, including evergreen trees, small trees, evergreen shrubs and deciduous shrubs.

Rhododendrons can be divided into deciduous and evergreen. Small leaves, often big green leaves. The colors of flowers are red, purple, yellow, white, pink and blue. Like cool, moist and cold-resistant, it grows mostly on slopes, alpine meadows, forest margins, stone walls and swamps at an altitude of 1000- 1400 meters.

[Edit this paragraph] Application value

In addition to ornamental purposes, some flowers can be used as medicine or extract aromatic oil, some flowers can be eaten, bark and leaves can be made into baking glue, and wood can be used as handicrafts. Rhododendron alpine has developed roots and is a good plant for soil and water conservation.

Rhododendron is an excellent bonsai material because of its lush foliage, beautiful appearance, strong germination, pruning resistance and peculiar root system. Gardens are most suitable for planting in clusters near forest edges, streams, Chi Pan and rocks, or scattered under sparse forests. Rhododendron is also a good material for hedges, and Mao Juan can also be pruned and cultivated into various forms. Rhododendron Garden has its own characteristics. Rhododendron can be used as medicine, and some can be eaten. The flower acid of azalea is non-toxic and can be eaten raw. The flowers of Rhododendron giganteum and Rhododendron pachydermum are beautiful vegetables for people in central Yunnan. The branches, leaves and flowers of Mao Dujuan are soaked and retted, which can be used as insecticidal pesticides; Rhododendron in Xing 'an, etc. , which can be used in pharmacy. Some kinds of bark and leaves are rich in extracts, which can extract tannin extract; Rhododendron's wood and root pocket are delicate and tough, which can be used for making bowls, chopsticks, pots, bowls, pipes, roots and other daily labor and art. Du Juanhua is sweet, slightly bitter, flat and fragrant, and has certain medicinal value in medicine. It can dispel wind and dampness, regulate menstruation and blood, soothe the nerves and remove dryness. People often cook this flower with pig's trotters, which can cure female leucorrhea. Long-term drinking has the effect of whitening and removing spots.

★ Warning:

The plants and flowers of Rhododendron flavum contain toxins, which can cause poisoning after eating by mistake; The flowers of Rhododendron leucocephala contain tetracyclic diterpenoids, which cause vomiting, dyspnea and numbness of limbs after poisoning.

[Edit this paragraph] Cultivation management

Seeding, cutting and grafting are commonly used for propagation, and layering and branching are also feasible. Sowing, evergreen azaleas are best sown with harvest, and deciduous azaleas can also store seeds until the next spring sowing. When the temperature 15 ~ 20℃, the seedlings will emerge in about 20 days. Cutting: Generally, semi-lignified branches of the current year are selected as cutting in May-June, and then shaded in shed. They can take root in 1 month at about 25 degrees Celsius. Rhododendron occidentalis takes root slowly, which takes about 60 ~ 70 days. Grafting, the propagation of Rhododendron occidentalis is widely used, often with twigs splitting, and the grafting time is not limited. The rootstock is mostly two-year-old Rhododendron, and the survival rate is over 90%. Wild rhododendrons and cultivated varieties from Mao Juan, Dong Juan and Xia Juan can be potted or planted in the shade. Xi Juan is potted all over the country, and the cultivated soil is mostly black mountain soil. Culture soil made of peat soil, Huangshan soil, humus soil, pine leaf soil, cinder and sawdust can be used as long as the pH value is between 5.5 and 7. O, good drainage, rich in humus. Pot filling is usually carried out in April or June 165438+ 10. Rhododendron roots expand slowly, so it is advisable to use 3-inch pots for 1 ~ 2 years, 4-inch pots for 3 ~ 4 years, change pots 1 time every 3 ~ 5 years, and trim roots at the same time. Water, according to the weather, plant size. Pot soil is dry and wet, which needs to be mastered flexibly. The water quality should be alkaline. When tap water is used, it is best to store 1 ~ 2 months in the water tank. Going out in mid-April is at the peak of growth, and the water demand is large; During the rainy season, water should be prevented; In the high temperature season from July to August, the evaporation is large, so it should be watered with the sun, and water should be sprayed on the ground and leaves at noon and night to cool down; 165438+1entered the room in early October. If there is heating in the room, the growth is still vigorous and the water demand is still large, especially when flowering and topping. If it is not heated indoors and grows slowly, it can be watered once every 3 to 5 days. Be thin, be fat and be diligent. For 2-4-year-old seedlings, in order to accelerate the formation of plants, the formation of new branches is often promoted by coring and bud picking. After the plant is formed, the diseased branches, weak branches and overlapping branches are mainly cut off, and thinning is the main method.

Key points of propagation: sowing, cutting, grafting and layering can be used for propagation.

[Edit this paragraph] Maintenance points

1. environmental conditions: it is best to cultivate azaleas indoors and indoors. Use indoor environment in winter. In the Yangtze River valley, as long as there are certain lighting and ventilation conditions indoors, there is generally no need for heating. The northern winter is extremely cold and dry, so it is suitable for cultivation in a greenhouse with moderate temperature (about 15℃). Outdoor venues, used in summer and autumn, with mud as the best, avoid cement. The venue should be spacious, ventilated and cool, with a shade shed, a reed curtain or a natural tree-lined shelter, and the light transmittance should be around 30%. It is forbidden to bask in the sun at night.

2. Potted soil requirements: Rhododendron likes loose, porous, well-drained, humus-rich acidic soil with PH value of 5.0-6.0. If clay or alkaline soil is used, it is difficult to survive. Especially Xia Juan and Yang Juan, they must be mountain soil. Mountain soil needs to be improved. At present, three kinds of cultivated soil are usually used. (1) It is prepared by mixing 7 parts of mountain soil, 1 part of dry moss sheet, 2 parts of dry humus soil and 1 part of dry fertilizer. (2) Stack 3 parts of mountain bark soil (topsoil), 3 parts of horse manure, 3 parts of deciduous weeds and 1 part of human manure in layers, and sieve after 1-2 years. (3) Mix 3 parts of mountain soil, 3 parts of humus soil, 4 parts of garden soil and 2 parts of sandy soil, and add 50g of sesame sauce residue and bone meal to each pot.

Third, the choice of flowerpots: flowerpots for planting azaleas can generally choose pottery pots and purple sand pots according to their uses. Clay basin has good ventilation and water permeability, which is beneficial to root growth. It is used for the cultivation of production units. Molded azaleas, especially those that have been molded, are generally planted in elegant purple sand pots for indoor and outdoor display. The teapot is exquisite in texture, rich in color and beautiful in shape, which can increase the ornamental value. The permeability of purple sand basin is not as good as that of clay basin. When planting, broken tiles (old tiles) should be placed around the basin wall to facilitate drainage. The size of the flowerpot depends on the age of the plant. Generally speaking, 5-inch flowerpots are used for 4-6 year-old plants. 6-inch flowerpot for 7- 10 annual plants; 11-15 8-inch pot for reproductive plants.

Fourth, improve water quality: it is best to use rainwater for watering azaleas, followed by river water and pond water. If tap water is used, it is best to store the water for 1-2 days, so that chlorine gas can be volatilized and then reused. When it is used, 0.2% ferrous sulfate is added, and it is poured every 7- 10 days in the growing season, and it is frequently used to ensure that the soil is acidic.

Five, fertilizer and water management: azaleas like wet, not too dry. More water is especially needed during flowering. In winter, azaleas have entered the dormant period, and the water demand is not much. Generally, water should be poured 1 time every 4-5 days, and around noon on sunny and warm days. According to the dryness of the basin soil, appropriate amount of water can be applied. In March, the roots of rhododendron germinated and the water demand increased. The growth and development of summer rhododendron is a little late, and the watering amount is less than that of spring rhododendron. Generally, water every two days in the afternoon 1 time. From April to June, azaleas bloom one after another, and the branches and leaves begin to sprout, which requires a lot of water. Generally, water 1 time every morning and evening. During the high temperature and drought season from July to early September, water 1 time in the morning and evening, and the amount of water should not be too much. At noon, water should be sprayed on the leaves and the ground to maintain a humid environment. From mid-September to165438+1October, the weather gradually turns cold, which is the adaptive period for the growth of rhododendrons. In order to prevent the autumn shoots from pulling out and enhance the cold resistance in winter, the watering amount should be reduced appropriately. Generally, water 1 time every other morning to keep it moist. Rhododendron prefers fertilizer. Generally, water with decomposed cake fertilizer, fish meal, broad bean or Chinese milk vetch, and human excrement and urine are prohibited. Apply 1 thin fertilizer every 10 day, with the concentration of 15%, and apply * * * 2-3 times, so as to promote the old leaves to turn green and sprout new roots. Fertilize 5-6 times from mid-May to early July to promote the growth of branches and leaves after flowers wither. If it rains continuously, dry fertilizer can be applied. Fertilize 1-2 times before entering the house and before the growth of azalea is about to stop.

6. Outdoor shading: it is advisable to see more sunshine before going out and flowering; At noon in flowering period, it should be shaded for a short time, with a light transmittance of 60%; The plum rain period from June to early July is the flowering period of azaleas, so try to see more sunshine. However, in the case of strong sunshine, it should be shaded from 9: 00 am to 4: 00 pm to avoid burning new leaves. From mid-July to early September, we should shade the sun from 8 am to 5 pm every day to prevent the sun from exposure. In the autumn growing season after September, the shading time can be shortened. Generally, it can be shaded from 10 to 4 pm, and it is advisable to see more sunshine after 10. Cut off long branches, weak branches, deformed branches and damaged branches after plastic surgery.

Seven, shaping and pruning: Rhododendron grows slowly, generally let it grow naturally, only after flowering, shaping, cutting off long branches, diseased branches, deformed branches and damaged branches.

[Edit this paragraph] Pest control

Pest control: During the hazardous period, the military pest control (also known as Wang Guan Bug) is sprayed with 40% dimethoate 1500 times, and sprayed with 1 times every 7 days for 3 times in a row. The control methods of leaf roller in terminal bud stage mainly rely on manual capture and killing, and larvae or pupae can also be killed by spraying 40% dimethoate emulsifiable concentrate or 1500 times dichlorvos.

Dicofol solution 1000 times can control red spider. Using 1500 times dimethoate or dichlorvos can control the cobia. The most common disease is brown spot, which can be controlled with 800 times Tobuzine or the same amount of Bordeaux mixture.

[Edit this paragraph] bonsai making

Rhododendron can be propagated by layering, cutting, branching and grafting. Bonsai can also be made of old rhododendron piles that have grown for many years and have simple roots. Most of them should be excavated and transplanted before the flowers wither in late autumn and early winter or spring. When transplanting, they should bring more soil, trim the trunk and taproot properly, cut off the branches that affect the shape, and leave more lateral roots and fibrous roots. For larger branches, check carefully to ensure that the shape is not needed before removal. First plant it in a soil basin or underground for green cultivation, and the soil should be sandy soil with good drainage. After planting the piles dug in late autumn and early winter, all of them are buried with sand, only a few branches are exposed, and after watering, they are covered with plastic bags to keep warm and moist. Piles dug in spring should also be buried in the soil for 2/3. After planting, keep the soil moist without watering, and then gradually remove the sand from the trunk after the plants germinate. During blank cultivation, leaves and trunks should be sprayed with water frequently to increase air humidity, but the roots should not be too wet, especially to avoid water accumulation, otherwise it will cause rotten roots. Pay attention to shading in summer to prevent sun exposure.

Rhododendron can be made into various forms of bonsai, such as straight dry type, inclined dry type, curved dry type, double dry type, multi-dry type, exposed root type, cliff type, attached stone type, flood and drought type and so on. Seedlings propagated by cutting, layering and other methods can be shaped year by year after 3-4 years of growth, and the modeling time is mostly before spring germination or summer and autumn growing season. Pruning is the main thing, winding is the auxiliary thing. When modeling, we should follow the principle of coarse first and fine later, properly wrap the trunk and main branches, and trim other branches for modeling. Because the branches of rhododendron are fragile and easy to break, be careful when operating. In the growing season, if a branch breaks, you can put yellow mud on the wound and wrap it with plastic film, which will soon heal and recover. However, the old azalea pile should be shaped by pruning, but some branches can also be properly tied. In order to improve the ornamental value, Mao Dujuan Laodui, which has grown for many years and has strong branches and beautiful appearance, can be used as rootstock, and excellent varieties of Rhododendron can be used as scions for grafting through docking or cutting. According to the situation of the stump, you can gradually remove part of the soil and lift the roots out of the ground, so that the roots are exposed in the air, which is simple and energetic.

Rhododendron likes warm and humid semi-cloudy environment and needs good ventilation. Usually it can be maintained under strong light, and it should be shaded in summer and early autumn to avoid exposure to the hot sun. Otherwise, the strong light will burn the leaves, but it should not be too shaded, so as to avoid the plants growing white and affecting flowering. It can be maintained in a cool shed or shade. Keep the soil moist during the growing period, but don't accumulate water. Pay attention to drainage in rainy season. When the air is dry, sprinkle water on plants and the surrounding ground to increase the air humidity and prevent the leaves from drying up. You can also cover the surface of the pot soil with a layer of soft grass to prevent the fine fibrous roots on the surface of the pot soil from being burned by the hot sun. Apply decomposed dilute liquid fertilizer every 15 days. In order to prevent yellowing, a small amount of black alum can be added to the fertilizer solution to make the leaves dark green and bright in color. Adding 1 ~ 2 times of phosphate fertilizer such as bone meal and calcium superphosphate in bud stage can promote the flowers to be large and colorful. Move indoors to the sunny place in winter, keep the soil above 0℃ from freezing, and control watering to make the basin soil slightly moist. Prune once a year after flowering, cut off pests and diseases, dead branches, cross branches, overlapping branches, weak branches and long branches, and cut off short branches appropriately, so as to make the plant beautiful in appearance and reasonable in branch distribution, strengthen ventilation and light transmission in the inner room, which is beneficial to plant growth. In spring or late autumn, the basin should be turned once every two years, and the basin soil should be rich in humus, fertile and loose slightly acidic sandy soil.

Function of plant dyes: As a foil for flowers, the function of branches and leaves of rhododendron has not been paid attention to. It is actually a natural dye. Uses: branches and leaves.

In the domestic environment, potted azaleas are better. It is appropriate to choose early spring or late autumn as the time to go to the basin. Rhododendron roots expand slowly, so it is advisable to use 3-inch pots for 1 ~ 2 years, 4-inch pots for 3 ~ 4 years, change pots 1 time every 3 ~ 5 years, and trim roots at the same time. Water, according to the specific situation of flexible grasp. When the temperature is low, there is little water; In high school, you should water while drying, but you must not accumulate water. Fertilization should be thin and diligent. For 2 ~ 4-year-old seedlings, in order to accelerate the formation of plants, the methods of coring and bud picking are often used to promote the growth of new branches; After the plant is formed, the diseased branches, weak branches and overlapping branches are mainly cut off, and thinning is the main method.

[Edit this paragraph] category

Rhododendron, also known as Rhododendron by the masses, refers to all kinds of red rhododendron, describing its bright red brilliance to make the mountains red. In fact, which rhododendron is red, today's plant taxonomy only takes "Yingshanhong" as one species (including many cultivated varieties). There are nearly 300 species in China and Yunnan province alone. China is the birthplace of rhododendron, and Yunnan is its distribution center.

Rhododendron azalea is a common rhododendron, which is named after it blooms all over the mountains. It is distributed in the mountainous areas above 500 meters above sea level such as Xijiang, Fenghuang Mountain, Zhuangkou and Lanshan in Huichang County, Ganzhou City, Jiangxi Province. Yingshanhong is known as "the king of woody flowers". Scholars at all times and all over the world wrote many beautiful poems praising Yingshanhong, such as a poem by Yang Wanli in the Song Dynasty, "Why don't you watch the spring breeze in the famous garden?" Every day, Jinjiang is like a brocade, and Qingxi shines on the mountains. "Praise the simple and tenacious vitality of Yingshanhong.

Climb the lush Yantou Mountain, and you will see the flaming azaleas steaming among the green hills and trees, in clusters, blooming so warmly and beautifully. Flowers are like red agate, standing upright in the wind, delicate and charming, with dense petals. The petals are very close, very close, attracting countless bee discs to fly around. Every flower is ethereal and subtle, picturesque and beautiful, which makes people linger.

Rhododendrons are mostly shrubs and small trees, one or two meters high. For ten days, Rhododendron and Rhododendron purpurea flowers crawled on the rocky ground, only a few centimeters high. There are dozens of feet of azaleas and thousands of flowers. The top of the azalea is an umbrella-shaped tidbit, which consists of several bell-shaped or funnel-shaped flowers, just like a full hydrangea. Most leaves are leathery. They are as big as a batch of handles and as small as nails. There is also a rhododendron with sharp leaves, more than 70 cm long and 20 cm wide. The fruit is a capsule and the seeds are as fine as dust. Sowing must be carefully managed before seedlings can be unearthed.