Silk cottonwood is a tree.

Arbors refer to tall trees with independent trunks arising from the roots, and the trunk and crown are clearly distinguished. Woody plants with an upright trunk and usually six to tens of meters in height are called trees. They tend to be tall trees with an obvious tall trunk. It can also be divided into four levels according to its height: Wei Qiao (above 31 meters), Da Qiao (21 to 30 meters), Zhong Qiao (11 to 20 meters), and Xiao Qiao (6 to 10 meters).

Trees correspond to low shrubs. Commonly seen tall trees are trees, such as kapok, pine, magnolia, birch, etc. Trees are divided into deciduous trees and evergreen trees according to whether they shed their leaves in winter or the dry season.

There are also differences between trees with needle leaves and broad leaves. Coniferous trees generally have dense branches and leaves, small crowns, and are mostly evergreen species. They should be avoided in scattered use in small courtyards and should be concentrated in a centralized layout. They are the main material that forms the background and barrier of small courtyards. Since evergreen coniferous plants generally have darker leaves, they tend to create a solemn atmosphere and give people a gloomy and dull imagination.

Therefore, it should not be used too much in small courtyards to avoid giving people a bad look and feel. Broad-leaf plants come in a variety of shapes, colors and textures, making them good landscape materials for areas with warm climates.

The role of trees in gardens

Arbors refer to tall trees with independent trunks from the roots, and the trunk and crown are clearly distinguished. Woody plants with an upright trunk and usually six to tens of meters in height are called trees. They tend to be tall trees with an obvious tall trunk. Arbors are the backbone tree species in gardens. They play a leading role in both function and artistic treatment, such as defining space, providing shade, preventing glare, regulating climate, etc.

Most of these trees can form rich seasonal changes in color, lines, texture and tree shape with the growth and fall of leaves. Even after the leaves fall in winter, they can still show the beauty of the lines of their branches. A large number of ornamental tree species should be planted to produce flowers in three seasons. Special emphasis is placed on the combination of slow-growing trees and fast-growing trees in the selection of plants, so that they can quickly become landscapes while ensuring long-term ornamental value.