Sophora japonica is a characteristic tree species commonly used in gardens. It has dense branches and leaves, and the shade is like a cover. It is suitable as a shade tree in the courtyard and is often used as a street tree in northern China. It is also suitable for planting in parks, buildings, neighborhood communities and lawns. Therefore, there are more and more Sophora japonica planted at present. How to prune the new species of Sophora japonica? Here's how to prune the new species of Sophora japonica reasonably.

First of all, the relationship between the fixed stem height and the branching point is unclear.

The fixed stem height is the trunk height of Sophora japonica after it grows to a certain height. At present, the most common fixed pole is 2.8 meters or 3 meters high. The branch point is the height of the main branch on the trunk closest to the surface. It can be said that these two concepts are very clear, and the height of the branch point is lower than that of the fixed stem. However, we can often see that the height of the stems of many Sophora japonica trees is basically the same as the branching points. This phenomenon is called "a pinch of hair", which means that the main branch we left is close to the incision of the trunk and is in a trajectory. It can be said that this phenomenon is the most common, and it also has a certain impact on the sales appearance and application of Sophora japonica. More seriously, choosing the main branch in this way will reduce the ability of the tree to resist the wind and snow load. When encountering strong convective weather and heavy snow, the main branch and trunk are prone to splitting.

Countermeasures: the branch point should be lower than the fixed stem height, and the selected main branches must be scattered up and down, not on the same track.

Second, the number of main branches is unscientific.

In practical work, we can often see three situations. First, there are too few main branches, leaving only two, which has become a "slingshot shelf"; Second, there are too many main branches, and the cut branches are not selected in time; The third is to blindly copy the "three strands, six forks and twelve branches", regardless of whether the tree is beautiful or not, only three main branches are reserved.

Countermeasures: "Slingshot frame" is unsightly, which also reduces the ability of the crown to resist snow and wind. Too many main branches will eventually affect the sales appearance and the growth of main branches. In addition, it is also incorrect to insist on retaining the three main branches. Sophora japonica generally has 3 ~ 5 main branches, and the number of branches to be retained should be determined according to the distribution of new branches. The ultimate requirement is that the crown is round, scattered up and down, each occupying its own side, and there is no shortage of corners.

Third, the length of the main branch is unreasonable.

We can often see that the length of the main branches of some newly planted Sophora japonica is very problematic, either too short, only about 20 cm, or too long, more than 100 cm. It can be said that both methods are unreasonable. Too short a main branch will inevitably affect the formation of the crown, while too long a main branch will affect the beauty of the crown and reduce the wind resistance of Sophora japonica.

Countermeasures: the length of main branches is generally controlled at 40cm ~ 60cm. When pruning, if the branches are thick, long and thick, you can leave a little more. If the growth is weak, short and slender, it should be kept short. In short, the length of the main branches of Sophora japonica is not fixed and cannot be absolute.

Fourth, the opening angle of the main branch is not appropriate.

The selected main branches should have a certain opening angle with the trunk, and its purpose is to make the crown round and wide. The main factor affecting the crown size is the opening angle of the main branch. During the investigation, the author saw that the opening angles of many main branches of Sophora japonica are relatively small, and some main branches even grow vertically, so the crown of the tree is like an egg placed vertically, which is not wide enough.

Countermeasures: When choosing the main branch, try to choose the branch with large opening angle. If the opening angles between all branches and trunk are not large, it is most appropriate to support them to keep the included angle between main branches and trunk at about 45 degrees. If the opening angle of the selected main branches and trunk can't meet the requirements and measures can't be taken, you can consider cutting off the branches, re-sprouting and re-selecting.

Fifth, when pruning, the bud position is unreasonable.

In practical work, especially before planting, pruning is extensive, and many people cut it casually. Not only do they not pay attention to the strength of the selected branches, but it is also unreasonable to leave "big flat heads" and leaves. The end result is that there are no new buds on the outside of the branch, but a bunch of buds appear inside. Unreasonable bud retention not only makes the tree look ugly, but also affects the opening of the tree.

Countermeasures: When pruning, you should carefully cut scissors, carefully observe each branch and make a choice. When cutting the remaining branches short, it is necessary to leave external buds under the incision, so as to make the later branches grow open and lay a good foundation for the wide crown.