There are many pruning methods for seedling modeling, mainly including bud stripping, tillering, coring, short cutting, branch bending and thinning. The shape of saplings varies with tree species:
1. Trunk cultivation
Trees with obvious terminal buds, such as Ailanthus altissima, Toona sinensis and Ginkgo biloba. It is not easy to produce competitive branches, and it is easier to keep dry. After transplanting, the main shoot should not be cut off, and the pruning should be light. Trees with poor terminal bud germination ability, such as Sophora japonica, paulownia, willow, etc. After transplantation, the main shoot must be cut off by 20 ~ 30 cm, and full buds should be left under the incision to promote germination and become an extended trunk. Competitive branches (branches that compete with the main branches for nutrients and with the central axis) should be cut short or thinned. Tree species with low trunks, such as Luan tree and Eucommia ulmoides. After transplantation, we should leave more branches and leaves, cultivate roots first, cut them off in the following winter, strengthen fertilizer and water management, and cultivate upright trunks.
2. Crown cultivation
Tall trees, such as poplars and beech trees, generally do not need artificial shaping. When competitive branches appear, they can be cut off in time. In order to ventilate the shed, dense branches, pests and dead branches must be removed. Trees whose trunks are not obvious under the leadership of the central government, such as Sophora japonica and Steamed Bread Willow, can be fixed at a height of about 2.5 meters, that is, cut off the trunk part above 2.5 meters, and then select 3-5 main branches radiating in all directions to cultivate them into backbone branches. In the second year, these main branches should be shortened by 35-40 cm to promote secondary branching, and an ideal crown can be cultivated.
3. Shrub modeling
(1) There are several main branches with many stems and leaves. From the surface, only 3-5 buds are left on each branch, and the upper part is cut off to make it branch again from the near surface, so that 3-5 dry stems can be cultivated, such as peony, forsythia, brocade flower and rose.
(2) Cluster type: Trees are plucked and pruned many times in their tillering stage or growing period, which makes the whole plant become low and cluster, such as plum blossom, Tang Di and bauhinia.
(3) After single stem round head transplantation, first raise the trunk and fix it at a height of 40-60 cm. After germination in the second spring, 3-5 main branches with uniform growth and suitable angles are left, and the height of the main branches is shortened by 20-30 cm in the second winter to promote secondary branching, such as purple plum and cotinus coggygria.
(4) Climbing type is mostly used for liana trees, so that the branches are attached to the wall and wound around fences or dead trees to grow, such as Parthenocissus tricuspidata, Lingxiao and Luoshi.
(5) Crawling covers the ground or rocks by using the natural creeping growth characteristics of branches. Such as spreading cypress trees.
(6) Scaffolding: plants are attached to a certain form of scaffolding by artificial traction to form a flower gallery or flower hole. Mostly used in lianas, such as honeysuckle, wisteria, grapes, etc.
(7) Spherical shape: after coring and pruning for many times, dense lateral branches are formed, and then the prominent lateral branches are cut short, and the whole crown is cut into round or oblate spheres, such as boxwood and Ilex cornuta.
(8) Trim or tie the whole plant into the shape of an animal or a building, such as juniper and juniper.