What principles should be followed in choosing garden plants for landscaping?

1. The principle of unification: also known as the principle of changing unification or the principle of multi-loading unification. When designing plant landscape, there should be some differences and changes in tree shape, color, lines, texture and proportion, showing diversity, but at the same time, it should maintain certain similarity, arouse a sense of unity, and be vivid and harmonious. If there are too many changes, the whole will appear chaotic, and even some parts will feel fragmented and lose their beauty. Too complicated colors can make people upset and lose their way, but they are straightforward, unchanging and monotonous. Therefore, we should master the principle of seeking change in unity and seeking unity in change.

Repetition method can best reflect the unity of plant landscape. For example, in the green belt of street trees, the same species should be planted at equal intervals. Trees of the same age, or shrubs of the same age planted under trees, have the greatest sense of unity in this precise repetition. When a city plans tree species, it is divided into keynote tree species, backbone tree species and general tree species. There are few kinds of tone trees, but a large number of them form the tone and characteristics of the city and play a unified role; However, there are many kinds of common tree species, each of which is small in number and rich in color, and plays a role in change. South of the Yangtze River, there are many kinds of bamboo. In the landscape design of bamboo garden, many kinds of bamboos are unified on the similar shapes and lines of bamboo leaves and bamboo poles, while clustered bamboos and scattered bamboos are scattered. Tall Phyllostachys pubescens, Dendrocalamus affinis or Dendrocalamus latiflorus are mixed with low bamboos and highly dispersed; The internode shapes of Bambusa gigantea, Bambusa gigantea and Bambusa gigantea are different. Pink bamboo, white bamboo, purple bamboo, jade bamboo, jasper golden bamboo, golden bamboo, yellow bamboo, Philippine white bamboo, etc. There are different colors. The ingenious planting of these bamboo species can illustrate the principle of seeking change in unity, as shown in Figure 6.

The landscape of gymnosperm area or commonly known as pine and cypress garden is unified to keep the landscape evergreen in winter. Pine trees are all pine needles and cones, but the needles of Pinus thunbergii are hard and dark green, while those of Pinus armandii and Qiao Song are soft and light green. The bark of Pinus tabulaeformis is brown and rough, the bark of Pinus armandii is gray-green and delicate, and the bark of Pinus tabulaeformis is white and mottled, which is rich in variety. Beauty pine bark is brown and red like beauty skin. Cyperaceae has scaly leaves, spiny leaves or subulate leaves, but juniper in Taiwan Province Province is steep. Taber. Shu Shu, pencil cypress; Cone cypress and phoenix cypress; Spherical and obovate juniper and cypress; The low and creeping Sabina vulgaris, Sabina vulgaris and Castanopsis carlesii reflect the posture of different species.

Second, the principle of harmony: that is, the principle of coordination and contrast. When designing plant landscape, we should pay attention to mutual connection and cooperation, embody the principle of harmony, and make people have a soft, calm, comfortable and pleasant aesthetic feeling. Find similarities and similarities, plant them together, and create a sense of harmony. On the contrary, differences and changes can produce contrast effects, produce a strong sense of stimulation, and form a feeling of excitement, enthusiasm and unrestrained. Therefore, in plant landscape design, contrast is often used to highlight the theme or attract attention.

When plants are planted together with buildings, attention should be paid to the coordination of volume and weight. For example, the main building of Zhongshan Memorial Hall in Guangzhou is coordinated with a huge white orchid with a crown diameter of 25m; On both sides of Sun Yat-sen Mausoleum in Nanjing, tall cedars are used to coordinate with the majestic mausoleum; The two ends of Brigham Park Bridge in England are coordinated by nine bodhi trees and nine European aesculus. The tall main building is closely clustered with nine cypresses, which looks like a huge cypress. Some rough building walls can be beautified with thick wisteria and other plants, but for exquisite tiles, mosaics and fine refractory brick walls, slender climbing plants should be selected for beautification. Bamboo should be planted in some small courtyards adjacent to the building colonnade in the south, and the bamboo poles and colonnade are very harmonious on the line, as shown in Figure 7. Some small proportion plants in rock gardens and spaces should choose dwarf plants or low horticultural varieties. On the contrary, the plant landscape near the huge overpass needs large colored shrubs or flowers to form large color blocks, in order to be in spiritual harmony with it.

In terms of color composition, any primary color of red, yellow and blue is mixed with the other two primary colors to form complementary colors, thus producing bright, dark, cold and hot contrast colors. When they are juxtaposed, they are mutually exclusive and have a strong contrast, showing a refreshing effect. Used well, it can highlight the theme and contrast the atmosphere. For example, red and green are complementary colors, yellow and purple are complementary colors, and blue and orange are complementary colors. An example is that in China's gardening art, a little red in evergreen trees is often used. In Sheffield Park, England, a red maple is deep in the grass on the roadside. Red attracts tourists to appreciate, changes the route of tourists and becomes the theme. Fortunately, the golden autumn leaves of the tree and the thick green copy of the tree are in sharp contrast in color, as shown in Figure 8. In the distance, the steep peaks of Yulong Snow Mountain are very harmonious with the trees of nearby cypresses, as shown in Figure 9. This therapy is often used in northern Europe and the United States. On the lawn of Shanghai Xijiao Park, a beech and a ginkgo tree are planted. In autumn, the leaves of the building are purplish red and the branches are soft and oblique, while the leaves of Ginkgo biloba are golden and the branches are thick and oblique, which is in sharp contrast. The natural scenic forests in Zhejiang Province often take evergreen broad-leaved trees as the skeleton, most of which are hard-leaved glossy trees of Pterocarya, with red, purple and Huang San maple fragrance. The collocation of black buds and plants has a strong sense of contrast, which makes autumn colors stand out, as shown in figure 10. The population and main scenic spots in the park are often emphasized by color contrast. Proper use of the appeal of color can add a lot of color to the scenery. Yellow is the brightest, symbolizing the light source of the sun. The deep and dense scenic forest makes people feel mysterious and timid, and they dare not go deep. Such as planting one or a cluster of trees or shrubs with yellow autumn or spring colors, such as Mu Ye, Sapindus mukoraiensis, Ginkgo biloba, Rosa davurica, Litang or Hypericum chinense. It can make the forest suddenly bright and play the role of a sense of space. Red is warm, festive and unrestrained, and it is the color of fire and blood. Strong stimulation, favored by active young people. Garden plants such as pomegranate in the fire, flaming flowers reflecting the red sky, and phoenix trees blooming like red clouds can all be applied. Blue is the color of the sky and the ocean, which has a deep, cool and quiet feeling. Purple has a solemn and noble feeling. In addition to wisteria, lilac, blue lilac, purple bubble flower, hydrangea and so on, there are many wild flowers with blue color in mountainous areas that need to be developed and utilized urgently. Such as Aconitum, Alpine Zi Yuan, Crocodile, Shuiku, Clematis macrophylla, Clematis macrophylla, Hedyotis diffusa, forget-me-not, Lonicera edulis, Wild Grape, Baihao, etc. White is leisurely and elegant, which is a symbol of purity and has a sense of softness, which softens bright colors. In gardens, white walls are often used as paper, and beautiful plants are planted in front of the walls for painting, which has a wonderful effect, as shown in figure 1 1. For example, there is a white statue of a teacher in the green space, with purple peaches and red plums. The colors match each other, and the theme of peaches and plums all over the world is also extremely abrupt, which is most popular among middle-aged and elderly people and introverted young people. There are many kinds of plants in the garden with colorful colors, and the commonly used gray-leaf plants can achieve the effect of unifying different colors.

Third, the principle of balance: this is a layout method when planting plants. If plant species with different volumes and textures are planted according to the principle of balance, the landscape will be stable and pleasing to the eye. For example, plant species with strong colors, huge volume, large quantity, thick texture and dense branches and leaves give people a heavy feeling; On the contrary, plants with light color, small volume, simple quantity, soft texture and sparse branches and leaves give people a light feeling; According to the surrounding environment, planting has regular balance (symmetry) and natural balance (asymmetry). Regular balance is often used in regular buildings and solemn cemeteries or magnificent royal gardens. For example, two symmetrical osmanthus plants are planted on both sides of the door; Planted in front of the building at equal distance, symmetrical nanmu, locust tree, etc. ; Symmetrical pine or cypress trees are planted in front of the mausoleum and on both sides of the main road. Natural balance is often used in gardens, parks, botanical gardens, scenic spots and other more natural environments. On both sides of the winding garden road, if tall cedar is planted on the right side of the road, a large number of flowering shrubs with small volume per plant should be planted on the adjacent left side to achieve balance.

Fourth, the sense of rhythm and the principle of sense of rhythm: regular changes in planting will produce a sense of rhythm. A willow tree among peach trees in Bai Causeway, Hangzhou is an example. Yun Qi Bamboo Trail is surrounded by bamboo forests. If you plant a tall Liquidambar formosana at a distance of 50m or 100m, when you walk along the trail, it will not be monotonous, but will change rhythmically.