Introduction to maintenance and Management of Ginkgo Biloba and Cinnamomum camphora in Shanghai

Shanghai Ginkgo biloba maintenance, camphor maintenance related knowledge introduction:

First of all, ginkgo biloba is a kind of deciduous tree, and the best season for transplanting is after falling leaves in autumn and winter and before sprouting in spring. You transplant 5 or 6 transplants after sprouting leaves, which is a non-seasonal transplant. Transplanting trees out of season generally requires shading, spraying and other technical measures according to the weather conditions. If the technical measures are not in place, the trees are likely to die.

Secondly, Cinnamomum camphora is an evergreen tree, and the best season for transplanting is in the early stage of its germination (about the first and middle of April). At the same time, we should pay attention to less damage to roots and soil balls, and at the same time, we should properly cut off about 1 inch of branches and leaves. When you transplant in May or 6, on the one hand, you have passed the best time for transplanting, on the other hand, you need to take other technical measures such as spraying because of the high temperature in Shanghai in May and June. You say, "the leaves of Cinnamomum camphora haven't grown yet." this sentence is difficult to understand, because camphor is an evergreen tree with branches and leaves when transplanting. As long as the branches and leaves are not withered and yellow and hang on the tree, they are not dead.

In addition, Magnolia and Magnolia are deciduous trees, transplanting in May and June belongs to non-seasonal transplantation, need to take corresponding technical measures, if the technology is not proper or not in place, it will lead to the death of trees. The initial bud of the newly planted tree is caused by the tree's own nutrients; the death of the bud indicates that the root system has not absorbed the necessary water in the new environment.

Shanghai ginkgo biloba maintenance, camphor maintenance questions answers Shanghai ginkgo biloba conservation, camphor maintenance questions answer-first, ginkgo is a kind of deciduous tree, the best season for transplanting is after falling leaves in autumn and winter and before sprouting in spring. You transplant 5 or 6 transplants after sprouting leaves, which is a non-seasonal transplant. Transplanting trees out of season generally requires shading, spraying and other technical measures according to the weather conditions. If the technical measures are not in place, the trees are likely to die. Secondly, Cinnamomum camphora is an evergreen tree, and the best season for transplanting is in the early stage of its germination (about the first and middle of April). At the same time, we should pay attention to less damage to roots and soil balls, and at the same time, we should properly cut off about 1 inch of branches and leaves. When you transplant in May or 6, on the one hand, you have passed the best time for transplanting, on the other hand, you need to take other technical measures such as spraying because of the high temperature in Shanghai in May and June. You say, "the leaves of Cinnamomum camphora haven't grown yet." this sentence is difficult to understand, because camphor is an evergreen tree with branches and leaves when transplanting. As long as the branches and leaves are not withered and yellow and hang on the tree, they are not dead. In addition, Magnolia and Magnolia are deciduous trees, transplanting in May and June belongs to non-seasonal transplantation, need to take corresponding technical measures, if the technology is not proper or not in place, it will lead to the death of trees. The initial bud of the newly planted tree is caused by the tree's own nutrients; the death of the bud indicates that the root system has not absorbed the necessary water in the new environment. Talking about the shaping and pruning of street trees

Abstract: from the description of pruning season, methods, pruning techniques, existing problems, solutions and matters needing attention, this paper expounds that pruning plays a decisive role in the unified and neat appearance, beautiful posture and healthy growth of street trees. Through pruning, the combination of branches can be adjusted, ventilation and light penetration can be improved, which is beneficial to the growth of street trees; the branches of diseases and insect pests can be cut off to reduce the latent and spreading conditions of diseases and insect pests; and the interference between street trees and public utilities can be reduced. Reduce the impact of typhoons.

Keywords: Street trees, pruning seasons, methods, shaping and pruning techniques, existing problems, solutions

1. Overview

Street trees are trees neatly planted on both sides of the road. In the city, street trees mainly take road shading as the main function, and have the functions of dust prevention, cooling, reducing motor vehicle exhaust pollution, beautifying the road environment and so on. The environment of street trees is more complex, first of all, it has something to do with traffic, some are affected by street direction, width, building height and so on, and there are many contradictions between urban areas, old urban areas and overhead lines, under the premise that the selected tree species are suitable, these contradictions must be solved through pruning to achieve the effect of crown and shade.

2. Pruning season

The pruning of deciduous street trees is usually carried out after defoliation in winter or before germination in spring. The Shanghai area is generally from mid-December to March of the following year, because the combination of branches can be re-adjusted by pruning when trees are dormant in winter, so that the storage and nutrients in the trees can be reasonably distributed after they germinate in the spring of the following year. and make the new branches have appropriate space to get sunlight for photosynthesis, promote the growth of trees, so as to achieve shade cooling and other functions of the street trees, and make the street trees have a unified and neat tree shape. To achieve the role of neatness and beauty.

In addition to winter shearing, street trees also peel their buds 2-3 times a year from May to June. In addition, the branches of some diseases and insect pests and the branches that interfere with the overhead line must be pruned at any time, and some new branches germinated on the winter cut, such as dense clusters, should also be thinned properly.

Evergreen street trees are generally best pruned before the first growth peak in spring and after the last growth peak in autumn. Shanghai is generally from March to April in early spring and from October to November in autumn.

3. Pruning method

3.1 thinning scissors

Cut off all the bases of withered branches, disease and insect branches, cross branches and over-dense branches in the tree, so as to improve the ventilation and light transmission conditions in the crown and avoid or reduce the phenomenon of barefoot in the bore branches. When thinning, the cut part must rely on the section, the cut should be on the opposite side of the cut bud, tilting 45 degrees, and the cut should be flat. If clustered branches and whorled branches need to be completely removed, they should be carried out in stages so as not to have too many wounds and affect the growth of trees.

3.2 short cut

Mainly cut off part of the tip of the branch, promote the lateral branch, and prevent the branch from protruding. The growing period is generally light, and the dormant period is generally heavy.

3.3 cut dry

To truncate the thicker main branches and backbone branches, this method can promote the renewal and rejuvenation of trees. In order to reduce the wound, it should be sawed obliquely downward from the upper part of the branching point, and the raised part of the lower part of the branching point should be retained, so that the wound is the smallest and easy to heal. In order to prevent the wound from decay due to water evaporation or the invasion of diseases and insect pests, the wound should be protected by applying protective agents or sealing the wound with wax or bandaging plastic sheeting to promote healing.

4. Common shaping and pruning techniques

4.1 Cup pruning

Cup-shaped pruning is mostly used under the overhead line, with a typical crown structure of "three strands, six branches and twelve branches". The trunk is 2.5-4 meters high. That is, after setting the stem, choose three main branches with suitable directions (120 °between the adjacent main branches and about 45 °with the trunk). Then two oblique branches close to the same plane were left on both sides of each main branch, and then two branches were also selected on each secondary branch. This process takes several years to complete before the cup-shaped crown can be formed. The street tree adopts cup-shaped pruning, which can vary according to the situation and according to the tree species.

After the skeleton is formed, the crown expands quickly, thinning dense branches and erect branches, promoting lateral branches, and inner branches can be properly retained to increase shading effect. If there is an overhead line above, do not let the branch touch the line, be sure to maintain a safe distance. The safe distance between the branches of the street tree and the overhead line includes horizontal spacing and vertical spacing, which varies according to the type of the line. In general, the safety spacing of power lines below 1 kilovolt is 1 meter, 3 meters under 1MUR 20 kV lines, 4 meters under 30 kV 110 kV high voltage lines, and 5 meters under 150 kV 220 kV EHV lines. The safe distance between branches and communication lines is 2 meters, and the safe distance between branches and communication cables is 0.5 meters. For the street trees near the side of the building, in order to prevent the branches from sweeping tiles, blocking doors and gambling windows, affecting indoor lighting and safety, the over-long branches should be cut short at any time.

During the growing period, we should often wipe the buds, do not tear the bark, do not leave residual branches. Cut off the cross branches, parallel branches, drooping branches, withered branches, damaged branches and erect branches on the back when pruning in winter.

4.2 Happy pruning

It is an improved cup-shaped form, the only difference is that the branch point is relatively low cup-shaped, the inner chamber is not empty, and the distribution of the three main branches has a certain interval, which is mostly used for tree species without central spindle or terminal bud self-cutting, and the crown develops naturally. In the Shanghai area, such as Albizia, when planting, leave the trunk 2.5 meters, with a maximum of no more than 3 meters or truncated, and the branch point near the side of the fast lane can be slightly higher. After sprouting in spring, 3 to 5 evenly distributed lateral branches in different directions were pruned to promote the growth of branches into main branches, and the rest were erased. The top of the main branch of the street tree on the same road or adjacent section of the road should be leveled. If it is determined that the main branch is cut a few meters from the ground, the main branch with high branch will be cut more, while the main branch with low branch will be cut less. In the growing season, only 3 to 5 suitable lateral buds were retained on the main branches, and 6 to 10 lateral branches were selected after germination in the coming year to promote secondary lateral branches to make the crown plump and symmetrical.

4.3 Natural pruning

Without affecting traffic and other public facilities, street trees can use natural crowns, such as tower shapes, oval shapes, and so on.

4.3.1 Street trees with central leading branches

For all tree species with obvious main axis, the height of the branch point is determined according to the characteristics of the tree species and tree specifications. During cultivation and pruning, attention should be paid to protecting its apical buds to grow upright upward. If the top of the trunk is damaged, choose a branch that grows upright upward or cut short at the strong buds, and erase the lower side buds and pull out the upright branches instead, so as to avoid the formation of a long phenomenon. This kind of tree species in Shanghai area, such as cedar, poplar and so on.

Conifers should cut off the vertical branches at the base, gradually increase the branching point as the tree grows, and protect the main tip to grow upright.

Broad-leaved tree species, such as Populus tomentosa, are not resistant to heavy wiping or heavy cutting, and should be mainly thinned in winter. The proper ratio of crown to trunk should be maintained when pruning, generally, the crown height accounts for 3 beat 5, the trunk (below the branch point) accounts for 2 prime 5, and the branch point next to the fast lane should be at least 2.8 meters high. Pay attention to the top and bottom positions of the three main branches should be staggered, the direction is symmetrical and the angle is appropriate. The lateral branches on the three main branches close to the trunk should be cut off in time, and the branches above the three main branches should be selected and arranged spirally upward to form a conical crown after germination.

The branches of Ginkgo biloba are truncated every year, and the lower branches should be longer than those of the upper branches, and form a conical crown after germination. After the formation, only the withered branches and over-dense branches are mainly thinned, and the amount of pruning is generally small.

4.3.2 Street trees without central leading branches

The tree species with weak trunk, such as dry willow, elm, Koeluan and Robinia pseudoacacia, are selected. The height of the branch point is generally 2-3 meters, and 6 main branches are left near the branch point. The distance between the main branches of each layer is short, so that the crown will naturally grow into an oval or oblate shape. The main objects of pruning every year are dense branches, dead branches, disease and insect branches, disabled branches and so on.

5. Common problems and solutions in street tree pruning at present

5.1 some street trees are trimmed by a single method

In Shanghai, such as Suzuki, "cup-shaped" or "happy-shaped" pruning is often used to avoid overhead power lines. With the improvement of road conditions in recent years, many road overhead lines have been put underground, which greatly alleviates the contradiction between the natural growth of street trees and overhead lines, and makes the pruning of Platanus trees no longer limited to the above two ways. areas with good space conditions can be pruned in a "natural" way.

5.2 Street tree-controlled high-strength pruning

At present, many street tree maintenance units in Shanghai are greedy for convenience and adopt a simple one-step "height control" method to prune street trees. the reasons for using this method do not hinder the following aspects: first, street trees are in a busy city and belong to old trees, which have never been pruned. The height of this kind of street tree is more than 10 meters, which requires mechanical operation to complete pruning, and the pruning process is relatively elongated. The geographical location also involves traffic, residents and other factors, and the project is so huge that the maintenance department has been delaying pruning without affecting the overhead lines and residential lighting, and has to take one step to "control height" to complete the pruning task when it has to be trimmed. Second, at present, most of the maintenance of street trees belongs to various maintenance contracting units, which will use alternate year pruning in order to reduce maintenance costs, and pruning is only limited to really unsightly parts. When the maintenance period is about to expire and is not ready to continue the contract, use one-step height control before handover, complete pruning at one time, and so on.

Although this method can be done under special circumstances, it will rapidly reduce the green amount of street trees and have considerable lethality to street trees. Therefore, the pruning of street trees or the promotion of standardized work, whether it is "cup-shaped", "happy-shaped" or "natural-shaped" pruning, should be gradually shaped to achieve non-renewal needs, then do not take a simple method of height control and strong cutting.

5.3 ineffective prevention and control of diseases and insect pests, but to renew and re-cut street trees

The prevention and control of diseases and insect pests of street trees in daily maintenance is not timely and complete. After the trunk and branches are eaten, they can only be renewed and re-cut to repair instead of prevention, which greatly affects the landscape and tree potential. On weekdays, it is necessary to strengthen the prevention and control of diseases and insect pests. Once diseases and insect pests are found, they should be prevented as soon as possible, giving priority to prevention, and even if they cannot be prevented, they should be treated early, small, and cured, and unsightly branches of diseases and insect pests should be cut off in time to prevent them from being discovered to the point where they must be re-pruned before they can be saved.

6. Pruning of several common street trees in Shanghai

6.1 Platycladus orientalis

Platanus mandshurica is a tree species growing in the spindle type with terminal buds. There are two pruning methods: coaxial trunk pruning and cup pruning, and cup pruning is more common in Shanghai. When cup-shaped pruning, it is necessary to cut off the head and set the stem above a certain height, which will promote the sprouting and branching of buds under the shearing mouth. At this time, the method of peeling buds and thinning branches by stages can be adopted, and 3-5 strong buds or main branches can be left. During the growing period, the upper lateral branches (buds) can be continuously picked and strengthened. After stopping growing in winter, two short lateral branches are selected in each main branch, thus initially forming a cup-shaped shape of "three strands, six branches and twelve branches". Then remove the original erect branches, cross branches, and then cut off the main branches every winter, properly retain the weak branchlets as auxiliary branches, subtract the overdense side branches, so that they interact with the side branches, but the length should not exceed the main branches. The strong branches should be retracted and pruned in time to prevent the crown from being too large and the leaf curtain layer too thin. at the same time, the disease and insect branches, cross branches, overlapping branches and erect branches should be cut off in time. After shaping, the big tree can be trimmed once every 2 years, which can prevent hair pollution.

Spindle trunk pruning of Platanus orientalis requires healthy and strong terminal buds and erect buds to develop robust branches at all levels so that the crown can be continuously expanded.

In recent years, natural pruning of Platanus acerifolia has been advocated in Shanghai. The natural pruning of Platanus orientalis is to cultivate the primary and secondary skeleton, expand the shade and allow the upper part of the tree to grow naturally. Daily pruning focuses on wiping buds, pruning disease and insect branches, growing branches, rotten heads and so on. Keep as many healthy branches as possible and increase the amount of green.

6.2 Albizia

Albizia in Shanghai area is mainly pruned in natural happy shape, and fixed pruning can be carried out when the trunk is as high as 2-2.5 meters or more. choose the side branches scattered up and down as the main branches, and do not choose the lateral branches at the same base point as the main branches. lest the force borne by one trunk is too large, cut short to the three main branches in winter, cultivate several side branches on each main branch, scatter each other and occupy a certain space. If the crown expands too far, it should be retracted and trimmed in time, and several robust buds in the lower part should be selected to gradually replace it, and a new trunk can be formed when it germinates in the next spring. This cycle can form a natural happy crown, like a large sunshade, fully demonstrating the unique function of the street tree. Usually pay attention to cut off dead branches, disease and insect branches, over-dense branches, cross branches and so on.

6.3 Koreuteria paniculata

After setting the trunk of Luan tree, 3-5 main branches with strong growth and uniform distribution were selected in the same winter or the next spring, about 40 cm were intercepted, and the rest of the branches were cut off. In order to concentrate nutrients to promote the growth of lateral branches, peel off the new buds from the main branches in time in summer. In the first time, 3-5 buds were selected for each main branch and 2-3 buds were left for the second time. The direction of the buds retained should be reasonable and the distribution should be uniform.

Branch thinning and truncation is carried out in winter so that the lateral branches on each main branch are evenly distributed and the direction is reasonable. Cut 2-3 side branches and cut off the rest, with a short length of about 60 cm. After a short period of 3 years, the crown is enlarged and the trunk is stout, forming a spherical crown.

Every winter, cut off dry and withered branches, disease and insect branches, cross branches, thin and weak branches, dense branches. If the extension of the main branch is too long, it should be retracted and pruned in time and continue to be the extension head of the main branch. For erect overgrown branches on the back of the main branch, cut off from the base. Keep some small lateral branches on both sides of the main branch, so that there is space, does not disturb the tree shape, and does not affect the growth of the main branch.

6.4 camphor

Cinnamomum camphora pruning should prune 4-6 lateral branches that grow more than the main branch under the terminal bud and peel off the lateral buds near the terminal bud to ensure the superiority of the terminal bud. If the lateral branch is strong and the main branch is weak, you can also keep the side, replace the main branch with the side, subtract the competitive branches of the new main branch, trim the overlapping branches on the trunk, keep 2-3 branches as the main branches, and make them scattered up and down, gradually shortening from the bottom to the top. In the growing season, it is necessary to cut short the competitive branches near the main branches to ensure the dominance of the top of the main branches. Pay attention to pruning the whorled branches in the crown so that the upper and lower branches are scattered with each other as far as possible. Thick main branches can be retracted and pruned to expand the crown. Camphor has more branches, so there are many tender shoots, so it is necessary to remove the tender shoots as far as possible and retain the old leaves.

7. Pruning matters needing attention

The order of pruning street trees should not be pruned randomly and without thinking. They should be pruned according to the order of "from base to tip, from inside to outside", that is, to see what form the crown should be trimmed as a whole, and then gradually prune the base of the main branch from the inside to the outside.

The score height of the street trees on the same road should be basically the same, and the branching height of the adjacent plants should be roughly the same.

The segmented pruning method should be adopted for the big branches that are too stout to prevent cracking.

Due to the influence of street direction, high-rise buildings and underground pipelines, street trees are often skewed and tilted, so the center of gravity should be adjusted by pruning as soon as possible. For the branches of the weaker side, as long as they do not contradict the overhead lines and buildings, light pruning should be carried out in order to ease the tree potential and balance the growth.

Tree pruning should comply with safety operation rules to prevent safety accidents. Carefully check whether the ladder and seat belt are secure before climbing the tree. At the same time, pay attention to the safety of pedestrians and nearby buildings.

References: 1. Lu Jianguo garden plant cultivation.

2. Garden construction management of Hangzhou Lantian Vocational training School, Department of Urban Construction of Zhejiang Province.

3. Shanghai Greening Administration textbook compilation group landscaping construction project construction and maintenance management in 2000.

4. Seedling management of landscaping construction project of Shanghai Greening Administration Bureau in 2000.

5. Hu Changlong ornaments the manual of shaping and pruning of flowers and trees.

6. Shanghai Green [2007] No. 0219 notice of Shanghai Greening Administration on standardizing the pruning and maintenance of street trees