Cultivation and Garden Application of Rhododendron

China has a long history of rhododendron cultivation, and artificial cultivation was recorded as early as the Han Dynasty. In the Tang Dynasty, rhododendron began to be used in private gardens. Because of its beautiful plant shape and colorful flowers, it is deeply loved by people. Rhododendron generally refers to the genus Rhododendron of the rhododendron family. There are about 960 species in the world. China is the birthplace and distribution center of rhododendron, with about 542 species, mainly distributed in the Hengduan Mountains of southwest, Yunnan, Xizang and Sichuan provinces.

Rhododendron likes cold and cool, and avoids hot sun. The growth temperature is from 15 ℃ to 25 ℃. Most varieties can withstand the low temperature of minus 8 ℃ to 12 ℃. Garden cultivation should be arranged under the forest and beside the valley. too strong light is easy to cause leaf yellowing, anti-curling and poor growth. lack of light affects flower bud differentiation and flowering quantity, and the soil is better in acid humus soil. Cuckoos like rainy, foggy, high-temperature environment, avoid waterlogging, planting land should have a certain slope, stagnant water is easy to cause rotten roots. Rhododendron roots are shallow and dense, so do not plant too deep when transplanting, otherwise the recovery period will be long and the growth will be slow. After a few years, the old roots will gradually rot, and new roots will grow again from the topsoil layer, forming "multi-layer roots". Rhododendron has no destructive diseases and insect pests except for seedling quenching disease, but the occurrence of brown spot and weevil will seriously affect the ornamental value of rhododendron, so it should be controlled in time. The flowering period is 15 to 25 days, and it takes about 140 days from flowering to fruiting and maturing. Wild rhododendron is mainly sown and propagated. Although cutting and grafting propagation can survive, it is difficult. Seedlings begin to blossom in 6 to 8 years, and rhododendron grows in 40 to 60 years, and its life span can be as long as hundreds of years.

Most of the wild azaleas live deep in the mountains and valleys, because of the inconvenient transportation, little-known, coupled with strict environmental requirements, cultivation is difficult, garden application is very little. At present, rhododendron horticultural varieties are widely used in urban landscaping, with few species and single color. With the improvement of people's appreciation level, a variety of wild rhododendrons will be widely used.

In the garden layout, rhododendron can be cultivated in a large area according to the ecological habits of different species according to the mountain, stone and water, so as to create a garden atmosphere of "natural simplicity, quiet elegance and winding path", thus forming a landscape landscape coordinated with the local natural environment. According to the difference of shape and color of rhododendron, mixed planting of many kinds of trees and shrubs can be used to form a garden group with scattered elevation and distinct plane, and the rhododendron can be planted in the foothills of the hills by imitating natural growth. to form the scenery of Rhododendron Mountain, Rhododendron Ridge, Rhododendron Valley and so on. Conditional parks can also be arranged according to the rhododendron classification system, closely related species are arranged adjacent to each other, and different groups are separated by paths in the garden, which can not only create a unique landscape atmosphere, but also allow visitors to increase their botanical knowledge during the visit. In landscaping, according to the shape and habit of rhododendron, the shrubby rhododendron with short plants, luxuriant branches and leaves and resistance to pruning can be planted by roadside, wall root or the edge of flower bed lawn to form hedgerows; evergreen large shrub rhododendron can form tree wall and flower screen; tall, straight branches, many flowers, bright leaves, dense crown or unique evergreen rhododendron can be planted alone in open areas such as lawn. The rhododendron with slender trunk and sparse branches can be planted in clusters, combined with garden pruning to form tree balls and flowers; large area landscaping should be based on flake planting, combined with color blocks, to win more and highlight the main body of rhododendron landscaping. In order to increase the overall ornamental effect, the rhododendron scenic spot can also be equipped with some background flowers and trees, such as pine, cypress, sweet-scented osmanthus, camellia, maple, plum blossom, crape myrtle, cherry blossom, etc., dotted with butterfly, white ear, sorrel, silk orchid, fern and Compositae to form a three-dimensional landscape.