After removing the covering, it is necessary to set up a shed to shade the sun in time. Shading time and shading degree should depend on the local temperature and climate conditions at that time, so as to ensure that its seedlings are not damaged by sun burns. In autumn, the time and intensity of light should be gradually extended. Until receiving sufficient light to improve the lignification degree of seedlings.

2. Rational fertilization

Fertilization is an important measure to cultivate strong seedlings; After the long roots of seedlings are unearthed, it is advisable to combine watering and diligent fertilization. At the peak of annual growth; Nitrogen-based quick-acting fertilizer should be applied to promote the vegetative growth of plants. In autumn, nitrogen fertilizer should be stopped and phosphorus and potassium fertilizer should be applied to improve the lignification degree of plants and the cold resistance of seedlings. It is suitable to apply farm organic fertilizer as base fertilizer in winter, which can not only provide continuous nutrients for seedling growth, but also play a role in heat preservation and soil improvement. With the growth of seedlings, the amount of fertilizer should be gradually increased to meet the demand for nutrients for seedling growth. ?

Step 3: Shape modification

Luan tree has a nearly spherical crown and a straight tree shape, and generally adopts a natural tree shape. Due to different uses, its plastic requirements are also different. Roadside saplings require straight trunk, 2.5-3.5m high primary branches, complete and plump crown and evenly distributed branches. Courtyard shade trees require a large and dense crown, and the height of primary branches is lower than that of street trees. In the process of cultivation, corresponding pruning measures should be taken around the above requirements, which can generally be carried out in winter or when transplanting.

4. Maintenance of Luan tree

After the trunk of Luan tree is fixed, in winter or next spring, choose to leave 3-5 strong and evenly distributed main branches, cut them short by about 40 cm, and cut off the rest branches. In order to concentrate nutrients and promote the growth of lateral branches, the new buds sprouted on the main branches should be stripped in time in summer. Select 3-5 buds for each main branch for the first time, and leave 2-3 buds for the second time, with reasonable direction and even distribution; Shorten the branches in winter, so that the lateral branches on the main branches are evenly distributed and the direction is reasonable. Cut off 2-3 side branches, all the others, and cut off the length by about 60 cm. This kind of short cutting for 3 years, the crown is enlarged, the trunk is thick, and the spherical crown is formed.