(1) planted separately
Single planting refers to the isolated planting type of trees. This kind of tree is also called an isolated tree. Sometimes, under certain conditions, it can also be two or three plants, which are closely planted to form a unit. But it must be the same tree species, and the spacing between plants should not exceed 1.5 meters, which is the same as that of single plant planting from a distance. Shrubs should not be placed under isolated trees. The main function of isolated trees is the need of composition art, as the main scene of local open areas, of course, it can also shade the sun. Isolated trees, as the main scene, are used to reflect the full growth and development of individual plants in nature, and their appearance should be tall and straight and magnificent.
(2) Intercropping
Intercropping refers to the symmetrical or balanced planting of two kinds of trees according to a certain axis relationship, which is mainly used to emphasize the entrance of parks, buildings, roads and squares, and at the same time, combined with shading and rest, as a configuration in spatial composition. In conventional planting, the trees of the same species and specifications are symmetrically arranged according to the central axis of the main scene, and the connecting line between the two trees is perpendicular to the axis and is equally divided by the axis. Conventional planting generally adopts tree species with neat crown. In natural planting, the opposite planting is asymmetric, but the left and right are balanced. Both sides of the natural garden entrance, both sides of the bridge head, both sides of the stone steps of the trail, both sides of the river entrance, the entrance of the closed space and the entrance of the building need natural introduction and induced planting. Natural planting is to achieve a balanced relationship with the central axis of the main scene as the fulcrum, distributed on both sides of the central axis of the composition, and must be the same tree species, but the size and posture must be different. The dynamic potential should be concentrated on the central axis, the vertical distance from the central axis should be close to the big tree, and the small trees should be far away. The planting points of the two trees should be connected in a straight line and cannot intersect the central axis at right angles.
(3) row planting
Row-by-row planting refers to planting trees and shrubs in rows according to a certain row spacing, or the row spacing has changed. The landscape formed by planting is neat, simple and magnificent. Row planting is the most widely used basic planting form in conventional garden green space. In natural green space, plastic parts can also be arranged. Row planting has the advantages of convenient construction and management. Planting is mostly used in areas with many buildings, roads and underground pipelines. Row-by-row planting combined with roads can play a role in landscape tailoring. Trees with regular crowns, such as round, oval, inverted oval, tower, cylinder, etc. You should choose to plant in rows instead of trees with sparse branches and irregular crowns. The row spacing depends on the characteristics of tree species, the size of seedlings and the main uses of gardens, such as landscapes and activity places. Generally, trees are 3-8m long and shrubs are 1-5m long. Row planting has two forms: equidistant and equidistant.
(4) Cluster planting
Cluster planting is usually a planting type consisting of two to ten trees or trees and shrubs. The ground with trees can be natural vegetation, grassland, grass flowers, rocks or terraces. Shrub is one of the most important planting types in garden green space. It mainly reflects the comprehensive image of tree group beauty, but this group beauty image is reflected by the combination of individuals, who are unified, but also have their own changes, contrast and set off each other. The selection of a single tree as a shrub is similar to that of a single tree, so it is necessary to choose a tree with special value in shading, tree posture, color and fragrance. Trees can be divided into simple trees and mixed trees. Shade trees are preferably in the form of simple trees. Generally, shrubs are not used or used less, and trees with tall crowns are usually suitable. However, as the main scene, induced scene and collocation scene in composition art, mixed trees and shrubs are often used. When trees are the main scenery, it is advisable to choose trees with mixed needles and broad leaves, which has a particularly good ornamental effect. They can be arranged in the center of the lawn, beside the water, by the river, on the island or on the mountain as the focus of the main scenery. In the classical landscape gardens in China, the composition of trees and stones is often set in front of the powder wall, and corridors can be used in the corner to form a small landscape of trees and stones with certain painting. Trees used as guides are mostly arranged at the entrance, fork in the road and bend, which fixes the scenic tour road into a curve and induces tourists to enjoy the colorful garden scenery according to the designed route. In addition, it can also be used as a sign of path divergence or cover the foreground of the path, thus achieving the effect of transferring another scene between peaks. Shrub design must be based on the local natural conditions and overall design intent, select the right tree species, fully grasp the biological characteristics of individual plants and their interaction, so that plants can get suitable conditions in growth space, light, ventilation, temperature, humidity, root growth and development, so as to maintain the stability of trees and achieve ideal results. The planting forms of cluster planting are: two trees, three trees, four trees and five trees.
(5) Group planting
Generally speaking, the number of individual trees planted in a group is more than 20-30. Trees mainly show the beauty of the group. Like isolated trees and bushes, trees are one of the main scenes in composition. Therefore, trees should be arranged in cheerful places with enough distance, such as large lawns near the forest edge, wide open spaces in the forest, small islands in the water, wide waterfront, hills and slopes, mounds and so on. In front of the main stand of the trees, at least four times the height of the trees and one and a half times the width of the trees should be reserved for tourists to enjoy. The planting scale should not be too large, and the composition is empty all around. The composition of the tree group and each tree should play a certain role in the appearance of the group. The combination of tree groups is preferably closed and layered. Visitors are not allowed to enter the trees at ordinary times, so it is inconvenient for tourists to enter, which is not conducive to enjoying the cool and rest. Trees can be divided into simple trees and mixed trees. A simple tree consists of one tree, and perennial flowers can be used as ground cover plants. The main form of tree species group is mixed tree species. The mixed tree species group is divided into five parts: tree layer, sub-tree layer, big shrub layer, small shrub layer and perennial herb vegetation. Each layer should be exposed, and the exposed part should be a prominent part of the ornamental characteristics of plants. The tree species selected in the tree layer should be particularly rich in crown posture, so that the skyline of the whole tree group is full of changes. The tree species selected in the secondary tree layer should be lush in bloom or beautiful in leaf color. Shrubbery should be dominated by flowers and trees, herbaceous ground cover plants should be dominated by perennial wildflowers, and the soil surface under the trees should not be exposed. The basic principle of arbor combination is that the arbor layer with high light should be distributed in the center, the secondary trees around, and the big shrubs and small shrubs at the outer edge. The planting distance of plants in the tree group should be varied, and it should form an equilateral triangle. It is forbidden to plant in rows, rows and belts. Evergreen, deciduous, foliage and flowering trees should be mixed in layers, small pieces and spots. The appearance of trees should have ups and downs, and attention should be paid to the seasonal changes and aesthetic feeling of the four seasons.