The plastic pruning of garden trees can usually be divided into winter pruning and summer pruning, strong pruning and weak pruning (heavy pruning and light pruning), sparse pruning and short pruning (short cutting).

1. Winter pruning and summer pruning

Winter pruning is carried out in the dormant period from autumn to winter, so winter pruning is also called dormant pruning. Pruning in winter has an important influence on the crown shape, branch growth and the formation of flower and fruit branches of garden trees, so the age of trees should be considered when pruning. Usually, the pruning of young trees is mainly based on shaping. For foliage trees, the purpose is to control the growth of lateral branches and promote the growth of main branches. For flowering fruit trees, we should focus on cultivating backbone branches such as trunk and main branch, so as to take shape as soon as possible and watch flowers and fruits in advance.

Summer pruning is carried out in the growing season, so it is called growing season pruning. Pruning in the growing season needs to cut off a large number of branches and leaves, which has a certain impact on the appearance of trees, especially flowering fruit trees, and should be pruned as lightly as possible. For trees with thick branches, if the upright trunk is cultivated on the basis of pruning in winter, a large number of new branches near the top of the trunk must be shortened in order to control its growth, adjust and assist the growth and direction of the trunk. Pruning of roadside trees in flower and fruit trees mainly controls the occurrence and growth of competitive branches, internal branches, upright branches and long branches, and concentrates nutrition for the vigorous growth of main backbone branches. Hedge pruning in summer is mainly to keep it clean and beautiful (and the cut twigs can be used as cuttings).

2. Strong pruning and weak pruning

According to the pruning intensity, it can be divided into strong pruning and weak pruning. In the pruning of ornamental trees, the strength is usually expressed by the length of the cut branches. Branches that are partially cut off are called strong pruning. On the other hand, a branch is called weak pruning when part is cut off less and part is left more. Weak pruning plays a great role in relaxing tree vigor, especially for branches that are not cut for a long time. During the young tree period, only the main trunk branches are strongly cut to a certain extent, and other branches are suitable for weak cutting or slow cutting.

3. Sparse and short cut (short cut)

(1) refinement

Cutting off the whole branch from its base is called thinning (also called thinning and pruning). It has no obvious stimulating effect on axillary buds on the mother branch near the incision, and will not increase the number of branches on the mother branch, but will only reduce the number of branches. The main purpose is to dredge the over-dense branches in the crown, reduce the number of branches in the crown, adjust the uniform distribution of branches, create good ventilation and light transmission conditions for the crown, reduce pests and diseases, avoid bare legs in the crown, reduce the number of buds in the whole tree, and prevent excessive germination of new shoots, thus not consuming nutrients and being conducive to flower bud differentiation and flowering and fruiting. The target branches for thinning are: withered old branches, pest branches, aging drooping branches, competitive branches, clustered branches, tillering branches, etc. (as shown in Figure 1, 2, 3).

Figure 1 refinement (1)

Figure 2 Thinning (2)

Figure 3 Thinning (3)

After the big branches are thinned, the growth of the branches above the wound will be weakened and the growth of the branches below the wound will be enhanced. The method of thinning many branches can be used to weaken the tree potential or alleviate the growth of branches with strong upper and weak lower. Large branches with a diameter less than 10cm can be sawed off from the trunk 10 ~ 15 cm, and then the kerf is slightly inclined up and down on the left. When sawing a big branch with a diameter greater than 10cm, a shallow wound should be sawed from bottom to top at a distance of 10cm from the trunk, then a small incision should be sawed from top to bottom at a distance of 5cm from the wound, and then a residual pile should be sawed from top to bottom near the trunk. This can prevent the wound from being too big to heal because of the tear of the branch itself in the middle of sawing. In order to prevent rain and bacteria from invading and eroding the wound, after sawing, it should be trimmed flat and smooth with a sharp knife and coated with disinfectant or oily paint (as shown in Figure 4, 5 and 6).

Fig. 4 thinning of big branches (1)

Fig. 5 thinning of big branches (2)

Fig. 6 thinning of big branches (3)

(2) Short scissors

The pruning method of cutting off some annual branches is called short cutting, which can be divided into the following types according to the length of short cutting:

(1) Light pruning at the top of branches is mainly used to prune the strong branches of flowers and fruits (it can also be said that the total length of the cut branches is 1/5 ~ 1/4). Objective: Shoot removal stimulates the germination of most semi-full buds in the lower part, disperses the nutrients of branches, promotes the production of a large number of short and medium branches, and is easy to form flower buds.

② Medium pruning (pruning belt length is 1/3 ~ 1/2) to cut off the full buds in the middle or upper part of the branch. Because the cutting buds are strong and strong, the relative nutrients are concentrated, which stimulates many vegetative branches. It is mainly used to rejuvenate some weak branches, and this method is used to cultivate the backbone branches and extension branches of various trees.

(3) Re-pruning the half-full buds at the lower part of the branches, because most branches (2/3 ~ 3/4 of the total length of the pruning belt) are cut off, which is more exciting. Because the buds under the cut are weak buds, short branches can be formed at the lower part except 1 ~ 2 vigorous vegetative branches. This pruning is mainly used for rejuvenation and renewal of weak trees, old trees and old weak branches.

(4) The extremely heavy cutting leaves 2 ~ 3 buds at the ring mark at the base of the branch, and the cutting buds are of poor quality because they are flat buds. 1 ~ 3 short and medium branches often germinate, and sometimes vigorous branches can germinate, but rarely. This method is suitable for pruning Lagerstroemia indica in gardens (as shown in Figure 7).

Different degrees of chopped new branches and their growth.

(5) Shrinking pruning (retraction pruning) Short-cut perennial branches are called retraction pruning. It can reduce the position of top advantage, improve lighting conditions and make the base of perennial branches younger. When pruning, the growth of lower branches is often affected by wounds, so it is necessary to temporarily leave appropriate protection piles. After the mother branch grows thick, the pile becomes thinner. Because the wound area is relatively reduced at this time, it does not affect the rooting of the lower part. The wound caused by the thinning of the branches did not obviously weaken the mother branches, so the protective piles could not be left. When the branch is extended, the incision is shortened, and the diameter of the wound is thicker than the first branch under the incision, the protective pile must be left. When thinning perennial non-main branches, if the mother branches are not prosperous and the wound is bigger than the cut branches, protective piles should also be left. When recovering the central leading branch, you need to choose the direction of cutting the lower vertical branch. When the direction of the vertical branch is consistent with the trunk, the posture of the new leading branch is natural. When the direction of the branch is not consistent with the trunk, the posture of the new leader branch is unnatural. The incision direction should be consistent with the extension direction of the branch under the incision (as shown in Figures 8 and 9, 10).

Figure 8 Shrinkage (1)

Figure 9 Shrinkage (2)

Figure 10 Shrinkage Shear (3)

4. Auxiliary pruning

(1) fracture

In order to prevent branches from growing too vigorously, or to distort branches to form various vigorous and powerful artistic shapes, branches often crack when buds sprout slightly in early spring. The rough method is to break the branches by hand, but when precious trees is subjected to artistic modeling, it should be cut obliquely with a knife, and the depth is 2/3 ~ 1/2 of the diameter of the branches, and then the branches should be carefully bent, and the inclined planes at the broken xylem parts should be used to resist each other (as shown in figure 1 1). Carefully manage and smear mud on the incision to avoid excessive transpiration.

Figure 1 1 branch fracture method

(2) Bud removal (bud wiping)

Removing excess buds is called bud removal. This measure can improve the nutrient supply of other remaining buds and increase their growth potential. Some remove the main buds, secondary buds or hidden buds to inhibit the growth potential or delay the germination period. For example, in order to prolong the grafting period of Chimonanthus praecox, flower farmers in Yanling, Henan Province often remove the main buds from the branches of the mother plant and let the new buds regenerate and then use them as scions.

(3) Choose the heart

The measure to remove the top of the new bud is called coring. The excised part is about 2 ~ 5 cm long. Tapping can inhibit the growth of new shoots and transfer nutrients to flower buds, fruits or branches, which is beneficial to the differentiation of flower buds, the hypertrophy of fruits or the enrichment of branches. However, after the core is removed, the buds on the upper part of the new branches can easily germinate into secondary branches, and the core can be removed after several leaves grow.

(4) Torsion skills

The measure of bending and twisting the new branch without breaking the mother branch is called twisting the new branch. This method is mainly used when the new buds grow too long. The stimulation produced by the twisting tip method is small, and it is not easy to promote the secondary tip. The disadvantage is that the twisted part is not easy to heal, and it will be cut flat again later. In addition, the method of "breaking the tip" is also useful, that is, replacing the twisted tip with the method of constantly breaking the new tip.

(5) Bending branches (bending branches, binding branches, binding branches)

This is induced measures, such as bending, binding or establishing branches or new buds. Because the growth of buds and buds has the top advantage, buds or buds can be controlled by bending branches. Vertical induction can enhance the growth potential; When induced horizontally, it has moderate inhibitory effect; When downward buckling is induced, it has a strong inhibitory effect. In some green spaces, this method is often used to tie trees into various artistic postures when planting key landscapes.

(6) picking buds

In order to get full flowers, such as peony, roses and so on. Side buds can often be removed to make the main buds grow fully. For some ornamental trees, the dead flowers are often removed after the flowers wither, which can not only improve the ornamental value, but also avoid the consumption of nutrients when they bear fruit.

(7) Picking fruits

In order to enrich the growth of branches and avoid excessive consumption of nutrients, young fruits are often picked. For example, roses and crape myrtle must be cut off from time to time in order to keep them blooming. As for the purpose of harvesting fruit, it is often to make the fruit fat, improve the quality or avoid the phenomenon of "big and small years", and pick the right amount of fruit.

(8) Sculpture

This is a measure to carve the wound near the bud or branch. The depth can reach xylem. When cutting above a bud or branch, nutrients and water concentrate on the bud or branch due to the obstruction of the wound, which can strengthen the growth potential. When cutting under buds or branches, the growth potential will be weakened, but due to the accumulation of organic nutrients, the branch buds will be enriched, which is beneficial to the thickening growth and the formation of flower buds. The deeper and wider the incision, the stronger the effect.

(9) Longitudinal damage

It is a measure to cut branches vertically with a knife and reach the xylem directly. The function is to reduce the binding force of bark, which is beneficial to the thickening and growth of branches. One twig can be injured longitudinally, and several twigs can also be injured longitudinally.

(10) lateral injury

It is to cut the trunk or thick main branches in several places with a knife and go deep into the xylem. The function is to block the downward transport of organic nutrients, enrich branches, facilitate flower bud differentiation and promote flowering, fruiting and high yield. This method is often used in jujube trees.

(1 1) girdling (girdling)

It is a measure to cut off and peel off a circle of cortical tissue on dry branches or new shoots with a knife or an endless belt. Its function is the same as that of transverse injury, but it is much stronger. The width of girdling is generally 2 ~ 10 mm, which depends on the branch thickness, the callus ability of tree species and the growth rate. But avoid too wide, otherwise long-term non-healing is not good for tree growth. It should be noted that this measure is not suitable for tree species that overflow or flow easily.

(12) Rooting

It is a measure to completely or partially cut off the root system of plants in a certain range. This method has the special effect of inhibiting the overgrowth of crown. Root cutting can stimulate the production of new fibrous roots, so it is beneficial to the survival of transplantation. Therefore, before precious seedlings leave the nursery or before transplanting trees, root cutting measures are often adopted. In addition, the roots can be cut off from the upper or lower part of the root system to promote the roots to develop into deep or shallow soil respectively.

(13) Tillering

It is a measure to remove root tillers near the base of plants or bud tillers on rhizomes. It can make plants concentrate nutrition and promote growth and development.

5. Others

(1) Treat auxiliary branches and competitive branches reasonably.

Auxiliary branches, make full use of the cavity in the crown to increase the leaf area and correspondingly increase the assimilated nutrients produced by photosynthesis. When carbohydrates are sufficient, a large number of flower buds can be formed and more flowers and fruits can be produced. If the tree grows faster, cut off the competing branches to keep the tree balanced. Two large lateral branches are born from the mother branch at the same time. When they grow forward in parallel, we should choose one branch that grows normally and cut off the other branch that competes with it to keep the local tree potential balance.

For the annual competitive branch, if the next adjacent branch of the competitive branch is weak, it can be cut off at the base of the competitive branch at one time. If the next adjacent branch of the competitive branch is strong, it can be cut down in two years. In the first year, competitive branches will be cut down again and again to curb the growth of competitive branches. In the second year, after the main branches grow thick, they are cut off at the base of Qi. If the competitive branch grows stronger than the original main branch and the next adjacent branch of the competitive branch is weaker, the weak original main branch can be cut off at one time. If the competitive branch grows vigorously, the original main branch is weak, and the next branch of the competitive branch is strong, then the original main branch should be cut off within two years to give the competitive branch the upper hand. Cut the original main branches repeatedly in the first year, and then cut them again in the second year.

The treatment of perennial competitive branches refers to the management of pruning trees and binding them with flowers and fruits. There is a certain space nearby, and the competing branches can be cut back to the lower branches to weaken their growth, form flower buds and blossom and bear fruit (as shown in figure 12).

Figure 12 Treatment of perennial competitive branches

(2) Cutting and cutting bud treatment

(1) The flat cut is approximately horizontal above the lateral bud, and a gentle slope is made on the opposite side of the lateral bud, and its upper end is slightly higher than the bud by 5cm. Located above the top of the lateral bud, it has the advantages of small incision and easy healing, and is a reasonable pruning method for ornamental trees.

(2) The cut of the stump cutting is approximately horizontal above the lateral bud, and there is a stump from the cut to the lateral bud. The advantage is that it does not affect the germination and elongation of lateral buds of cuttings. The problem is that the wound is difficult to heal. When logging in the winter of the following year, the residual piles should be cut off (as shown in figure 13, 14, 15).

Figure 13 Treating the bud at the incision (1)

Figure 14 Treatment of Bud at Cutting (2)

Figure 15 Relationship between Incision and Bud Distance

(3) The steep incision inclines too fast, the wound is too big, and too much water evaporates, which hinders the nutrient supply of the incision bud, so it can inhibit the growth of the incision bud and promote the growth of the next bud (as shown in figure 16).

Figure 16 Schematic Diagram of Cutting Direction

(4) When the incision of the large lateral branch is flat, it is easy to sink into the trunk and affect the healing, so the incision is slightly convex into a steamed bun shape, which is more conducive to healing.

Cutting too close to the bud pruning is easy to cause the bud to die, and cutting too far from the bud pruning is easy to cause the dead pile.

In the future, the growth direction of new branches varies with the position of buds. Leave the upper and lower buds, and new branches will grow up and down. When the inner and outer buds leave, new branches will grow inward and outward (as shown in figure 17).

Figure 17 Growth direction of upper and lower branches and buds

(3) Pruning useless branches

In the process of pruning, we should pay attention to pruning useless branches such as long branches, dead branches, sprouting branches, sprouting branches, rotating branches, endogenous branches (anti-branches), parallel branches and upright branches (as shown in Figure 18 and 19).

Figure 18 Unnecessary pruning of branches (1)

Figure 19 Unnecessary Branch Pruning (2)

(2) Plastic surgery

Plastic work is always combined with pruning, so the plastic period and pruning period are unified except for special circumstances. The forms of plastic surgery can be summarized into the following three categories.

1. Natural Plastic Surgery

Using various pruning techniques, according to the natural growth characteristics of tree species, adjust and promote the crown shape, and form a natural tree as soon as possible. The long branches, redundant branches, inner branches, combined branches, dead branches, pests and diseases that affect the tree shape should be suppressed or cut off, and attention should be paid to maintaining the symmetry and integrity of the crown. Natural shaping conforms to the growth and development habits of tree species, so it can often promote the growth of trees, give full play to the tree-like characteristics of the tree species, and most easily obtain good ornamental effects.

2. Artificial plastic surgery

In order to meet the special requirements of landscaping, trees can sometimes be artificially shaped into various regular geometric figures or irregular shapes. The formation of geometric shape is based on the constitution law of geometric shape. For example, we must first determine the length of each side of a square crown; The radius of the spherical cap should be determined. The shaping of non-geometric shapes includes wall shaping and sculpture shaping. Wall plastic surgery is a kind of plastic surgery to achieve the purpose of vertical greening of walls, which is common in European classical gardens and has U-shaped, ribbed and fan-shaped shapes. Sculpture plastic surgery is a shape created according to the intention of plastic surgeons. Attention should be paid to the coordination with the surrounding landscape when shaping, and the lines should not be too complicated, and the outline should be clear and concise. Artificial shaping is contrary to the growth and development characteristics of tree species, which is not conducive to the growth and development of trees, and once it is not pruned for a long time, its shaping effect is easy to be destroyed, so it should be fully considered in specific applications.

3. Natural and artificial mixed plastic surgery

According to some requirements of landscaping, the natural tree shape is more or less artificially transformed. Common ones are cup shape, natural happy shape, multi-leader trunk shape, central leader trunk shape, cluster ball shape, scaffolding shape and so on.

(1) cup shape

This tree has no central trunk, only a fairly high trunk, and there are three main branches on the upper part of the autonomous trunk, which are evenly distributed around. Three branches are divided into six branches, and then two branches are divided from the six branches to form 12 branches, which is the so-called "three branches, six branches and twelve branches" tree. This geometrically regular branch is not only neat and beautiful, but also has no upright branches and inward branches on the crown, which must be cut off once found. This tree shape is very common in urban street trees, such as peach trees and locust trees on overhead lines.

(2) The shape of natural happiness

It is improved from the cup shape. The cup shape has no central trunk, and the center is not empty, but the branches are low. The three main branches are distributed at certain intervals, radiating outward from the autonomous trunk and developing towards the center, so it is a natural happy shape. However, the main branches are not branched, but scattered around, so the crown is not completely flattened, which can make better use of space, and the sunshine in the crown is transparent, which is conducive to flowering and fruiting. In the garden, this shape is used to prune peaches, elms, plums, pomegranates and other flowers and fruits.

(3) Multi-tap dry form

Leave 2 ~ 4 central trunk, and arrange lateral main branches in layers on it to form a uniform crown. This model is suitable for tree species with strong vitality, which can make the crown more beautiful, advance the flowering period and prolong the life of branchlets, and is most suitable for shaping flowering trees and shade trees.

(4) Central leadership.

Leave a strong central leading cadre and arrange the main branches of evacuation on it. This form is one of the less processed forms of natural trees. This form is suitable for tree species with strong axis and can form a tall crown, which is most suitable for shaping shade trees, single trees and conifers.

(5) Nerve plexus

This plastic method is quite similar to the shape of multi-tap trunk, except that the trunk is short and the main branches left on the trunk are clustered. This shape is mainly used to shape small trees and shrubs.

(6) Scaffolding shape

This is the shaping of vines. Firstly, various forms of scaffolding, cloisters and pavilions are built, and after planting lianas, they are pruned, straightened and induced according to their growth habits.

Summarizing the three plastic methods mentioned above, the natural type is the most widely used in garden green space, which saves manpower and material resources and is easy to succeed. Secondly, natural and artificial plastic surgery is a kind of plastic surgery with the purpose of large flowers, dense flowers or plump fruits, which saves labor and effort and needs to be properly combined with other cultivation techniques. Generally speaking, artificial body shaping is only used locally or in places that need special beautification, because it is very labor-intensive and requires more skilled personnel.

(3) Pruning and shaping trees for various garden purposes.

1. Pruning and shaping of conifers and cypresses

Generally speaking, most pine and cypress trees can't be trimmed and shaped, or they can only be shaped naturally.

Pine and cypress trees generally have strong apical advantages, and their main branches are mostly arranged in whorls or near whorls. In order to cultivate their natural tree shape, reasonable artificial pruning must be carried out. If there is competition between the stout lateral branches and the main branches near the top, it is necessary to prune the competitive branches repeatedly to weaken their growth potential. The main branches of each layer should be evenly distributed, and the main branches of each layer should be kept at a certain interval. The main branches of each layer should not overlap and be arranged in dispersion, so as to expand the contact surface with the sun as much as possible. The overlapping branches, parallel branches and over-dense branches should be retracted and pruned in time to make the tree sparse, symmetrical and beautiful.

2. Pruning and shaping shade trees and street trees

Generally speaking, the tree crown adopts natural tree shape, rather than special plastic work. The trunk height of shade trees should adapt to the requirements of the surrounding environment, and there is generally no fixed regulation, which mainly depends on the growth habits of tree species.

Street trees have the main function of shading the road, and also have the functions of health care and beautifying the street. However, there are contradictions between street trees and traffic, upper and lower pipelines and buildings. In order to solve these contradictions, they must be trimmed. For example, in order to facilitate traffic, the branch point of street trees should be 2.5~3.5m, and the minimum should not be less than 2m. The main branches grow obliquely, and the drooping branches must be kept above 2.5m to prevent scraping. The branch point of roadside trees in suburban roads can be slightly higher, and the branch point of tall trees can be increased to 4 m, and the branches of roadside trees in the same street must be neat and consistent.

In order to solve the contradiction of overhead lines, cup-shaped pruning can be used to avoid overhead lines, and branches touching wires can be cut off at any time in summer except winter every year. The vertical distance between the branches and the telephone line is 1m, and the vertical distance between the branches and the high-voltage line is1.5m. For the trees off the crown, the oblique branches are cut off again, and the other side is lightly cut to adjust the tree potential. In short, when pruning street trees, you should always cut off dead branches, pests and diseases, weak branches, cross branches and overlapping branches. For long branches and short branches, cut them off at strong buds; Neck branches become thinner year by year to prevent annular peeling from weakening tree potential. The long branches and upright branches on the back will generally become thinner. If there is space around, light and short branches can be used to promote secondary branches to make up for the space.

3. Pruning and shaping of shrubs

According to the growth and development habits of tree species, it can be divided into the following pruning and shaping methods:

(1) Leaf species that bloom first and then develop.

After flowering in spring, you can prune the old branches and keep the ideal tree posture. For tree species with dense branches, such as Prunus tomentosa and Eucommia ulmoides, weak branches and diseased dead branches can be pruned appropriately. Renew the branches with heavy shears and keep the tree shape with light shears. For tree species with arched branches, such as Forsythia suspensa and Yingchun, the old branches can be cut off again to promote the emergence of strong new branches, so as to give full play to their tree-like characteristics.

(2) Species of new shoots that bloomed that year.

Pruning can be done in winter or early spring. Such as hydrangea and plum blossom. , can be pruned again to make the new shoots strong. For example, if roses and pearl plums bloom endlessly during the growing season, then the old branches should be pruned again in early spring, and then the new branches should be pruned after flowering, so that the branches can bloom again.

(3) Ornamental branches and leaves

Heavy cutting should be carried out in winter or early spring, and most branches and leaves will germinate after light cutting. Another example is the cold-resistant ornamental plants such as red rosewood, which can be pruned in early spring to make the winter branches give full play to their ornamental functions.

(4) Trees with strong germination ability or trees that are easy to dry in winter.

You can cut grass from the ground in winter and sprout new branches in spring, such as Lespedeza, Vitex negundo, Buddleja officinalis and so on. This method is of great practical value to the combination of greening and the production of branches as weaving materials.

4. Trimming and shaping of rattan

(1) scaffold type

For tendrils and winding vines, this method is often used for pruning and shaping. When pruning and shaping, it is necessary to prune again near the ground, make a few strong main vines, then vertically attract the main vines at the top of the trellis, and evenly distribute the side vines on the trellis, which will soon become a shade shed. Commonly used such as wisteria, grapes, etc.

(2) Gallery style

Often used for tendrils and winding plants, and occasionally used for adsorbing plants. Because the veranda has a side lattice, the main vine cannot be induced at the top of the veranda too early, otherwise it is easy to form a side space.

(3) Fence type

Mostly used for tendrils and winding plants. After the lateral vines are induced horizontally, the lateral branches are cut short every year to form a neat hedge. Commonly used such as honeysuckle, lingxiao, wisteria and so on.

(4) Attached to the wall

This formula uses adsorbed plants as materials. The method is simple. Just introduce vines into the wall and gradually cover the wall with suction cups or tree roots. For example, Parthenocissus tricuspidata, Lingxiao, Euonymus fortunei and Ivy all use this method. In addition, some gardens set up scaffolding 20 ~ 50 cm in front of the wall, and plants, such as vines and vines, are planted in front of the scaffolding and bloom in front of the building wall. When pruning, pay attention to completely cover the wall roots, and each vine branch should be evenly distributed on the wall, so as not to overlap each other.

(5) Vertical type

For some species with thick stems and vines, such as wisteria, they can be cut into erect shrubs. If this formula is used on the roadside or park lawn, it can get good results.

5. Hedge pruning and shaping

Hedgehog, also known as hedge, hedge, should pay attention to the design intent and requirements when pruning. Natural hedgerows generally do not need special pruning and shaping measures, but only need to properly control the height and cut off sick old and dead branches in the process of cultivation and management. For the whole hedge, special pruning and shaping work is needed.

(1) The form of the whole hedge

There are various forms (as shown in Figure 20). Some are cut into geometric shapes, some are cut into tall hedges for sculptures, rocks, fountains and other backgrounds, and some use the hedges themselves as landscapes; There are also single or clustered trees, which are trimmed into birds, animals, buildings or sculptures with commemorative and educational significance.

Fig. 20 Several forms of integral hedge.

(2) The pruning and shaping method of the whole hedge.

Among the above kinds of trimming and shaping, experienced people can cut them off at will, which can meet the requirements of neatness and beauty. Unskilled people use thread rope to shape first, and then trim them with thread as the boundary.

Hedgehogs are most prone to dry and bare lower parts, so it is best to have a trapezoidal side section when pruning, so as to keep the lower branches and leaves thick and not easy to be exposed due to sufficient sunshine. On the other hand, if the cross section is inverted trapezoid, the lower part of the hedge will be exposed quickly, and the good effect cannot be maintained for a long time (as shown in Figure 2 1).

The side part of a hedge trimmed and shaped.