1, cut dry in time
After stopping growing in spring every year, before the arrival of the second growing season (usually in early July), cut off the curved part at the top, send out new branches, and choose a vertical branch as the new trunk.
2, reasonable pruning
The so-called reasonable pruning is to keep as many side branches as possible without affecting the growth of the trunk, which is beneficial to the thickening and growth of the trunk, speeding up the lignification process and avoiding the bending of the trunk. Under the specific operation:
(1) Horizontal branches and branches close to horizontal branches are generally not cut, so let them be pruned naturally.
(2) The competitive branches that affect the growth of the main spike should be cut off in time.
(3) Control the growth of other lateral branches that do not form competitive growth, and cut them off in time when their thickness reaches 1/2 of the trunk thickness. Prevent the trunk from being too sharp and increase the height of the trunk. If it is cut too late, the wound is not conducive to healing.
Step 3 cut it dry again
For 2 ~ 3-year-old seedlings, when they start to grow in spring, if the seedlings have no obvious main spikes or are too skewed, they should be cut again, and the cutting opening should be selected at the beginning of skewness. In addition, it is necessary to stick a layer of callus antiseptic film on the trimming mouth to promote wound healing.
4. Other measures
Applying more phosphorus and potassium fertilizer in seedling stage and spraying new high-fat film on leaves in growing season are beneficial to strengthen photosynthesis, accelerate lignification process and prevent trunk bending. In short, in order to cultivate qualified Sophora japonica seedlings, the key lies in: ① timely cutting the head and changing the head. ② Avoid excessive pruning. ③ Maintain a reasonable density.