1, bud stripping

In early spring, in the early stage of branch germination, the redundant and useless buds on the branches are stripped off by hand, which is called "bud stripping". When peeling buds, pay attention to protect the useful buds (for future use as main branches), and keep the buds in a reasonable direction and evenly distributed.

2. Land to the tiller

When the new buds are not lignified, it is called "tillering" to remove the useless new buds sprouting on the trunk or roots. Tillering should prevent tearing bark or leaving dead piles.

3. Shortcuts and coring

Cutting off a part of a branch is called "short cutting". In the growing season, removing the tips of branches is called "pinching". The short section of perennial branches is called "retraction". There are three kinds of short cut: light short cut, which is cut off at the full bud of the middle and upper branches to promote the growth of medium and long branches and enhance the ability to form branches; Heavy and short cutting, cutting in the middle and lower parts of branches, will reduce the number of branches after cutting, but it can promote the vigorous branches.

4, thinning branches

Cutting off useless branches is called "thinning branches". Thinning branches can make the trees ventilated and transparent, which can promote the local area; Weakening branches can concentrate nutrients and enhance tree potential. When thinning branches for deciduous trees, the incision should be flush with the growing branches, leaving no dead branches. For sparse shrubs, it is necessary to cut off the land. When thinning large branches of evergreen trees, a small stake of 1-2 cm should be left, not flush with the growing branches.

Second, the pruning period

1, winter pruning

Pruning from autumn defoliation to spring germination (165438+1October to March) is called "winter pruning". Places that are easy to cause bleeding after pruning (juice flows out from the cutting mouth after cutting off branches, which is called bleeding), such as grapes, walnuts, Pterocarya stenoptera, Acer truncatum, etc., should be pruned before defoliation in June+10, 5438.

2, summer pruning

Pruning from spring germination to autumn defoliation (April to165438+1October) is called "summer pruning". Summer pruning mainly includes operations such as stripping buds, removing tillers, removing cores, loosening over-dense branchlets, and adjusting the angle of main branches.

Third, the methods and requirements of trimming modeling

1, cultivation of deciduous trunk

(1) Dry cultivation of transplanted seedlings (seedlings transplanted in the spring of that year). Trees with full terminal buds, such as Populus euphratica, Populus pekinensis, Fraxinus mandshurica, Toona sinensis and Ginkgo biloba. , should not be cut off after transplantation. Trees with poor terminal bud germination ability, such as Populus tomentosa, Sophora japonica, Robinia pseudoacacia, willow, etc., must cut off their main shoots by 20-30cm after transplantation, and choose full buds to stay under the incision to sprout the elongated trunk.

(2) Maintenance method of seedlings (seedling raising in the second year after transplanting). Fast-growing tree species, such as poplar and willow, are pruned in winter mainly to raise the branch point to 1/2-3/5 of the tree height, and the competitive branches appearing in the upper part should be cut off. Trees with obvious terminal buds, such as Acer truncatum, have a higher degree of seedling transplantation, leaving more small side branches and removing thicker and upright side branches. When the trunk reaches the required height, it should be transplanted for the second time to help straighten the trunk, and then gradually increase the branch points after the trunk hardens. Trees whose trunks are not easy to grow straight, such as Phellodendron amurense, Luanshu, Euonymus japonicus, Eucommia ulmoides, etc. After transplantation, we should leave more branches and leaves, keep the roots well, cut them dry in the winter of the second year after transplantation, and strengthen the management of fertilizer and water in the second year, that is, they can grow into upright trunks.

2. Deciduous crown cultivation

(1) Tall deciduous trees, such as poplars and willows, generally do not need artificial shaping. Only when there are strong competitive branches in the upper part, should it be drained in time, otherwise it is easy to have two-headed main trees.

(2) Deciduous trees without central trunk, such as Sophora japonica, Acer truncatum, steamed bread willow, etc. , should be combined with the second transplant, pruning at a height of 2.5m, that is, all the trunk parts above 2.5m are cut off, and then 3-5 main branches radiating in all directions are selected to cultivate backbone branches. In the second year, these main branches should be shortened by 35-40 cm to promote their secondary growth.

(3) aft that grafted Sophora japonica survive, pruning is carried out at the drooping part of the branches in winter, so that the branches sprout upwards, and the crown expands outwards to form an umbrella crown.

3. Shrub pruning modeling

(1) single stem round head modeling. This tree is suitable for elm plum, purple plum, cotinus coggygria and other tree species. Its shaping method is: after transplanting, raise the trunk and cut it by 46-60 cm. After germination in the next spring, leave 3-5 main branches with uniform growth and appropriate angles, cut off the useless branches at the lower part, and cut it by 25-35 cm in the next winter to promote its secondary branching, thus developing into a single-stem round head shape.

(2) Dry shrubs, such as forsythia, Taiping flower, brocade flower, rose, etc. After transplanting, only 3-5 buds are left on each main branch from the surface, and the upper part is cut off to make it branch again from the near surface to form 3-5 dry and multi-dry shrubs.

(3) Hedge shrubs, such as ten sisters, climbing roses, roses and other shrubs that cannot stand upright, must be hedged high to increase ornamental value. In the stage of tending management, it is mainly to cultivate roots and 3-5 thick main vines, and at the same time, to remove redundant branches and vines during germination.

4. Pruning modeling of evergreen trees

(1) Conifers. Generally, the top of conifers has obvious advantages and the trunk is easy to raise. Among them, the main branches of Pinus tabulaeformis and Pinus armandii are whorled. If there are too many main branches in a year, the advantage of the central trunk will be easily weakened. Therefore, when there are too many main branches in rotation, only 4-5 main branches with reasonable and even distribution can be left in each round, and thinning can be carried out. When the seedlings planted as street trees leave the nursery, they should be cultivated once a year after they are 6-7 years old in the nursery, and the height of the branches can reach more than 2.5m when they leave the nursery.

Pine and cypress, such as Pinus bungeana and Sabina vulgaris, tend to grow long branches from the lower part, resulting in the phenomenon of double stems. In the process of nursery tending, the long branches tied to the central leadership should be deleted at any time. If the terminal buds of the above-mentioned Pinus species are damaged, the adjacent side branches (main branches) should be tied up with upright wooden sticks in time to replace the trunk.

(2) hedge seedlings. Hedge seedlings require dense branches below. In order to achieve this goal, the shoots should be cut off in the spring one year before the seedlings leave the nursery to promote more branches in the lower part.

(3) Lianas or climbers. Wisteria should be picked in autumn (after beginning of autumn in August) and stop growing early, so as not to reduce its cold resistance because the shoots are not easy to lignify. For Euphorbia humifusa, Lingxiao, etc. , mainly to cultivate roots, leaving 3-5 main vines.