Rhododendron is divided into five strains: Spring Rhododendron, Summer Rhododendron, West Rhododendron, East Rhododendron and Mountain Rhododendron. It refers to the variety that blooms first and then germinates, and blooms in the middle, late April and early May. The so-called Spring Rhododendron was first introduced to Shanghai from Japan in the 1920s and 1930s, and the local flower farmers formed a unique variety in China through the breeding and hybridization of the original species. Because it blooms in spring, it is named Spring Roll, which has continued to this day.
Rhododendron in spring is native to China, and also distributed in Malaya Peninsula and South Asia. There are abundant species of evergreen rhododendrons in the mountainous areas of Sichuan, Yunnan and Guizhou, and deciduous rhododendrons are distributed from northeast to south China. Natural communities are distributed in high mountains and grow on shady slopes, belonging to semi-shade plants. I like to be born in places with cool climate, high air humidity and acidic soil. I am also barren-resistant, but not water-resistant.
Because of its hairy leaves, spring rolls are also called "Mao Juan", and because of its huge leaves, it is also called "Rhododendron macrophylla". It is a variety and hybrid of the original species of Rhododendron argenteum and Rhododendron Jinxiu. Evergreen, erect, solitary or clustered, with strong growth potential, long oval leaves, about 10 cm long and 3 cm wide, dark green in color, blooming in late April and early May, with flowers clustered at the top and covered with branches. Three flowers in one bud, 8 cm in diameter, wide corolla, trumpet-shaped, mostly single, 5-lobed. After flowering, 3-5 or 6-7 new buds appear, and flower buds begin to form in July and August. Cold-tolerant, many kinds of underground, because of its rapid reproduction and growth, it was used as the rootstock for grafting rhododendron or other new varieties. At the same time, in landscaping, it is also often used for ground cover color blocks or landscaping. Branches and leaves are the longest in spring and bloom from early May to June, so they are called Xia Juan. Xia Juan's main parents are said to be Rhododendron Gaoyue and Rhododendron Mayday.
It is characterized by an open evergreen shrub with low plant shape, strong branching, plump crown, pruning resistance, alternate leaves, short and dense internodes, leaves 3-4cm long, 0/-2cm wide, narrowly lanceolate to oblanceolate, thick, dark and hairy, and crimson after frost. The flowering period is from mid-May to June and can last until July and August. Corolla is wide, trumpet-shaped, about 5 cm in diameter, and the larger one is 7-8 cm. Single flap, double flap and nested flap vary greatly, including round, light, soft and hard, wavy and folded. Four seasons green, four seasons open, yellow, red, white and purple wonders, four seasons cultivation, beautify the environment. It can be potted or planted in the shade. Rhododendron trees cultivated on the balcony in summer should be trimmed neatly and arranged in a ball shape. Its shape is very beautiful. Rhododendron trees cultivated in the yard in summer should be cut into umbrellas to add interest and beauty. Suitable for group planting in damp and shady forests and rocks, and also suitable for planting in trees, forests, streams, Chi Pan and lawn edges in gardens; Hedges and flowers can be planted together on the shady side of buildings. Some kinds can be used as bonsai. Dong Juan is a variety of Rhododendron japonicum and its many hybrid offspring. It is imported from Japan, so it is called Dong Juan, because it corresponds to the western azaleas. Dong Juan blooms in spring, and some places are included in spring rolls.
Main features: low plants, soft branches, messy branches and many transverse branches. The leaves are oval, thin, hairy, tender green and shiny. There are 3-4 branches in the bud, each bud has 1-3 flowers, sometimes 4-5 flowers, and the flowers are dense. It's really "look at the flowers rather than the branches". Corolla is funnel-shaped, small, with a diameter of 2-4 cm and a tube length of 2-3 cm. Most calyx evolved into corolla, forming two sets, namely double sets and double sets. There are many colors, such as red, purple, white, pink, light yellow, white and green, edging, brocade and so on. There are 5 stamens, some of which become highly double flowers. The flowering period is several days earlier than that in Mao Juan. From July to August, old leaves fall and flower buds form at the same time. Not resistant to strong light, can be planted in the open field, has strong germination, is extremely resistant to pruning, and has slender flowers, branches and leaves. It is a good material for making color blocks in courtyard greening and an ideal material for making potted flowers. Because of its gorgeous flowers, it is a popular species. In particular, Belgium Rhododendron, because it is a hybrid horticultural variety between Europe and America, is called Western Rhododendron, also known as Western Rhododendron. After 1892 was introduced from Japan, the variety names of Xi Juan were translated into Japanese, so the varieties introduced from Japan in China are still translated into Japanese. At the same time, China has bred many new varieties by crossing with Xi Juan. Therefore, there are about 200-300 species of Xi Juan in China.
The main characteristics of Xi Juan are: (1) the plants are low, semi-open, slow growing and evergreen; (2) The branches are short and strong, and the branches are green or red in that year, which is related to the color. Red branches have more red flowers, and green branches have white, pink and pink flowers; (3) The leaves are thick and dark green, with many branches, the size of which is between Mao Juan and Dong Juan, and the hairs on the leaves are few, and the shape changes are many. From the change of leaf tip color, we can know the color of flowers, such as white and transparent leaf tips, white or other light colors, red leaf tips and red flowers. Among them, by standardizing cultivation techniques, the four-season flowering period of rhododendron can be advanced to New Year's Day and Spring Festival. The flower pattern is large, with a diameter of 6-8 cm, and the maximum can reach more than 10 cm. The petals of double petals are mostly rich and varied in shape and color, which has high ornamental value. Judging from the local planting situation for many years, Xi Juan has poor adaptability and disease resistance. You can only use potted plants, shade properly in summer and keep warm in winter. The western cuckoo introduced from Dandong by Chaiqiao since 1984 is mainly Belgian cuckoo. At present, there are 7 varieties of Belgian rhododendron series, 3 varieties of German rhododendron series, 4 varieties of Hamburg series, 3 varieties of Baijiaren series, 5 varieties of Sihai series, 6 varieties of Wuqiu series, 4 varieties of Crown series and 32 varieties of * * series. The main representative varieties are: Five Treasures (Wuxi: Brocade), Crown (Dandong: icing on the cake) and Four Waves (Wuxi: Tiannv Dance). It is an ideal material for making potted flowers. Rhododendron alpine is an alpine evergreen shrub or small tree of Ericaceae.
Morphological characteristics of alpine rhododendron: evergreen shrub or small tree, with plant height of 65,438+0-3m, stout branches, foliage, top branches, thick leathery, length of 6-65,438+02cm, width of 2-5cm, and flowering period of April-May. The flower pattern is mainly set petals and double petals, and there are also a few single petals, and the flowering period is about 65,400. Colors are white, pink, reddish, pink, yellow and so on. It generally grows in Shan Ye at an altitude of 600-800 meters and has strong adaptability. After artificial domestication and cultivation, it is expected to become an evergreen ornamental plant in garden green space.
A simple identification method for Dong Juan, Curly, Xi, Juan and Xia Juan;
1. Similarity: All four rhododendrons belong to deciduous rhododendrons; Cold-resistant, afraid of heat; The soil should be fertile, acidic, loose and transparent.
Second, the difference:
1. Different sources: Dong Juan and Xia Juan belong to Rhododendron Tianzhu; Rhododendron in China is Rhododendron; The cuckoo is a western cuckoo.
2. Different shapes: Dong Juan is short, 1 to 2 meters high, with scattered branches; Mao Juan is tall, 2 to 3 meters high, with vigorous growth and young branches densely covered with brown bristles; West Rhododendron is short and strong, with tight crown; Xia Juan's body is very small, the branches are slender and dense, and the crown is plump and tidy.
3. Leaf shape: Dong Juan's leaves are thin and light, and the hair has little luster; Mao Juan's leaves are big and long, rough and hairy; Rhododendron leaves are dark green with little hair, and the leaf shapes can be divided into flat leaves, pointed leaves, twisted leaves, long leaves and broad leaves. Xia Juan leaves are narrow and closely arranged.
4. Flowers: Dong Juan's flowers are the smallest, blooming in April, with dense flowers. Petals or tubular petals are emitted from calyx petals, with few double petals and many colors; Mao Juan's flowers are large and simple, wide and funnel-shaped, with few double petals, and the colors are generally red, purple, pink, white and compound colors; Rhododendron occidentalis is the most beautiful, and its flowering period is April-May. Xia Juan blooms first and then flowers. The flowering period is from mid-late May to mid-June, and the color and petals are the same as Xi Juan.
5. Cultivation and propagation: Rhododendron occidentalis is delicate. It takes 2 months to propagate hairy roots by cutting, and the survival rate is low, so grafting propagation is generally used. The other three cuttings take root quickly and have high survival rate. They can be planted in pots or in the ground. This method is the most widely used, and its advantages are simple operation, high survival rate, fast growth and stable characters.
① Time: West Rhododendron from late May to early June, Mao Dujuan in early and middle June, and Spring Rhododendron and Summer Rhododendron in middle and late June. At this time, the branches are old and tender, and the climate is warm and humid.
(2) Cutting, that is, taking the newly lignified branches of that year, breaking them with the heels, smoothing the hairy heads, cutting off the lower leaves, keeping the upper 3-5 leaves, and keeping them moist for cutting;
③ Cutting management: Cutting substrate can be orchid soil, mountain humus soil, yellow core soil, vermiculite, etc. The cutting depth should be 1/3 to 1/2 of the ear length. After cutting, water should be sprayed, plastic film should be covered with moisture, and proper shading should be given. The cutting substrate should always be moist within one month, so that Mao Juan, Chunjuan and Xia Juan can take root in about one month.
Cutting propagation, it is best to use a new shallow pottery jar with a diameter of 20 cm, because it is breathable and easy to take root. The substrate can be cultivated soil mixed with 20% humus garden soil, 40% horse manure chips and 40% river sand. Cutting time is best in spring (May) and autumn (65438+1October), when the temperature is between 20-25℃, which is most suitable for cutting. When cutting, select the semi-lignified and robust branches of the year as cuttings and press the knife with the daughter-in-law. Cut 6- 10 cm from the node, and the incision should be smooth and tidy. Cut off the lower leaves, leaving only 3-4 leaflets at the top. Buy 1 Vitamin B for injection12. After unsealing, soak the strips in the medicinal liquid, take them out and dry them for a while before cutting. Before cutting, the soil in the pot should be sprayed with a watering can the day before, but not too much. The next day was just wet, which was most suitable for cutting. The insertion depth is 3-4 cm. When inserting, first leave a hole in the soil with chopsticks, then insert the cuttings, compact them by hand, let the pot soil fully contact with the cuttings, and then water them again. After inserting, it is best to cover the flowerpot with a plastic bag, tie the bag mouth tightly with a belt, open it when watering is needed, and tie it tightly after watering. The cut flowerpot should be placed in direct sunlight, and the cut flowerpot soil should be sprayed with water for 65,438+00 days every day, except in rainy days, 65,438+0 times in cloudy days and twice in dry climate, but the amount of water sprayed should not be too much every day. After 10, always keep the soil moist. Shade it for 4-5 weeks and let it gradually receive some sunshine until it germinates. It usually takes about 2 months to take root. After that, it only needs to be shaded for 2-3 hours at noon, and the rest of the time can be exposed to light, so that it can make its own nutrients in its photosynthesis. Multiple ears can be grafted from one rootstock, with many varieties, fast growth, good plant type and high survival rate.
① Time: from May to June, twig splitting method or abdominal transplantation method was used;
② Rootstock: 2-year-old Mao Juan was selected, and the thickness of new branches and scions was appropriate. Mao Juan "Jade Butterfly" and "Purple Butterfly" are better rootstocks.
(3) scion: on the mother plant in Xi Juan, cut off the tender branches with the length of 3 cm to 4 cm, remove the lower leaves, keep 3 to 4 leaflets at the end, and cut the base into a wedge shape with a blade, with the section length of about 0.5 cm to 1.0 cm. 5. Grafting management: cut off the new shoots of Mao Juan at 2 cm to 3 cm, remove the leaves at this position, longitudinally cut 1 cm, insert the wedge-shaped end of the scion, align with the cortex, bind the joint with plastic film tape, and tie the mouth with plastic bags to keep moisture; Put it under a shade shed to avoid direct sunlight and exposure. After 7 days, as long as there are small drops of water in the bag and the scion does not wilt, it is possible to survive; Unpack the package after 2 months, and unpack the binding tape in the spring of the following year. Rhododendron is a shade-loving plant, and direct sunlight is not good for its growth. Therefore, it is best to choose a shady place, or take this into account when designing greening, and deliberately arrange trees in a special garden. Rhododendron likes acidic soil with good drainage, but because all kinds of gardens and landscapes use cement as roads and pavements, the soil in Rhododendron planting area is alkaline, so it is necessary to replace the soil in planting area and add a certain amount of peat soil.
North of the Yangtze River, potted plants are used for viewing. Potted soil consists of humus soil, sandy soil and the same soil (7:2: 1) mixed into cake fertilizer, manure and so on. , stir well and plant. Generally, change pots or soil in March in spring. The area south of the Yangtze River is mainly planted in the ground, which should be planted before germination in spring. The place should be in a ventilated and semi-cool place. The soil should be loose and fertile, rich in humus, and acidic sandy loam is suitable, and it is not suitable for water accumulation, otherwise it is not conducive to the normal growth of rhododendrons. After planting, be sure to water it. Rhododendron requires the soil to be wet, not wet. Generally, in spring and autumn, cuckoos planted in the open field can be watered once every 2-3 days, and in hot summer, at least once a day. Do not use alkaline water for daily watering, and pay attention to the water temperature not to be too cold when watering, especially in hot summer, when watering thoroughly with cold water, the soil temperature suddenly drops, which affects the water absorption of roots and interferes with the physiological balance of plants.
After planting and soil improvement, water 1 time to make the roots fully contact with the soil, which is beneficial to the survival and growth of the roots. Pay attention to watering during the growth period, and gradually increase the amount of watering from March, especially in summer, always keep the basin soil moist, but don't accumulate water. Reduce watering after September, and then water after entering the house in winter. At the end of winter and the beginning of spring every year, it is best to apply some organic fertilizer as base fertilizer to Rhododendron Garden. After the azalea blooms in April-May, because the plant consumes a lot of nutrients during the flowering period, with the germination of leaf buds, new buds are taken out and fertilizer can be applied every 15 days. After lodging, most branches have stopped growing. At this time, it is in the high temperature season, and the physiological activity is weakened, so topdressing can be stopped. After autumn, the climate is getting cooler and there is autumn rain, and the temperature and humidity are suitable for the growth of azaleas. At this time, topdressing can be carried out for the last time, and fertilization is generally not suitable after winter.
Rational fertilization is the key to raising rhododendron, and it is preferable to fertilizer. During the spring and autumn growing season, 10 times liquid water of pancake fertilizer should be applied every 1 0 day, which can be fermented with rice washing water, peel and vegetable leaves. In autumn, you can supplement some phosphorus and potassium fertilizers, and you can use fish and chicken viscera and meat washing water, rice washing water and some peels. In addition to the homemade household fertilizers mentioned above, you can also buy some household fertilizers to use, but remember to apply them "thinly". Apply dry fertilizer 1 time (small amount) before winter, and don't apply base fertilizer when changing pots. In addition, when watering or fertilizing water, tap water should not be used directly, but should be acidified (adding ferrous sulfate or vinegar) and then used when the pH value reaches about 6. Pruning is an important measure in daily maintenance management, which can regulate growth and development, thus making growth vigorous. Daily pruning needs to cut off a few diseased branches and delicate old branches, combined with crown shape to delete some over-dense branches, which is beneficial to plant growth. The cuckoo garden should be inspected frequently, and the dead branches and diseased branches should be removed in time to reduce the spread of pests and diseases in the cuckoo garden.
Pick buds in time during bud stage, so as to concentrate on supplying nutrients and promote colorful flowers. Pruning branches is usually carried out in spring and autumn. Cut off cross branches, over-dense branches, overlapping branches and weak branches, and remove residual flowers in time. Plastic surgery is generally a natural tree, with a little artificial modification, which is arbitrary because of the tree shape. If you want to see flowers in the Spring Festival, you can move the potted flowers to the sunny place at 20℃ in the greenhouse in June+10 in 5438 or 20 days before the Spring Festival. Other management is normal, and flowers can be seen during the Spring Festival. If you want to see the flowers in May 1 day, you can move the flowerpot indoors below 5℃ for cold storage before germination in early spring, move it to the sunny place in the greenhouse at 20℃ in April 10, and move it out on April 20th, so you can see the flowers on May 1 day. Therefore, the temperature can adjust the flowering period, and it will open at four o'clock as you like. In addition, the plants cut immediately after flowering can bloom in late June at 65438+ 10; If pruned in the peak season, the flowering period can be delayed by about 40 days; If pruning is combined with cutting, the flowering period can be postponed to February of the following year. Therefore, pruning in different periods also affects flowering time.