(1) Preparation before construction
1. The urban greening project must be constructed in accordance with the approved greening project design and relevant documents. Construction personnel should master the design intent and make good preparations for the project.
2. Before construction, the design unit shall make design disclosure to the construction unit, and the construction personnel shall conduct on-site check according to the design drawings. If there is any discrepancy, it shall be submitted to the design unit for design change.
3. According to the greening design, the selected planting materials should comply with the provisions of its product standards.
4. Plans and schemes shall be prepared before the project starts:
(1) construction procedures and schedule;
(2) Labor days and total labor days of each working procedure;
(3) List of materials required for the project;
(4) the use plan of machinery and transport vehicles and tools;
(5) Construction technology and safety measures;
(6) construction budget;
(7) Construction organization design should be prepared for large-scale and key greening projects.
5. Green planting
(2) Planting materials and sowing materials
1, the planting materials should be well developed, robust, free of pests and diseases, and the specifications and shapes should meet the design requirements. The principle of vigorous growth, plump posture, excellent varieties and closed seedling source.
2. The excavation and packaging of seedlings should meet the current industry standards: the size of soil balls is 8- 10 times that of DBH. When packing, the soil ball at the root should be wrapped with straw rope to make the soil ball not loose.
3, foliage plants, the leaf color should be bright and the leaves are full.
4. Grass blocks and grass rolls used for lawn paving should have the same specifications, with straight edges and no more than 5% weeds. The thickness of soil layer of grass block should be 3 ~ 5 cm, and the thickness of soil layer of grass roll should be 1 ~ 3~5cm.
5. Seeds of lawns, grass flowers and ground cover plants used for sowing shall be marked with varieties, strains, producing areas, production units, weights, harvest years, purity and germination rate, and there shall be no pests and diseases. Seeds imported from other places should have quarantine certificates. The germination rate is above 90% before use.
(3) Soil treatment before planting
1. Before planting or sowing, the physical and chemical properties of the soil in this area should be tested and analyzed, and corresponding measures such as disinfection, fertilization and soil introduction should be taken.
2. The minimum planting soil thickness required for plant growth shall comply with the provisions in Table 5.2.
Table 5.2 Minimum Soil Thickness for Planting
Vegetation type herbaceous flowers lawn ground cover small shrub large shrub shallow root tree deep root tree
Thickness of soil layer (cm)30 30 45 60 90 150
3. The soil in the planting area contains harmful components such as construction waste soil, as well as strong acid soil, strong alkali soil, saline soil, saline-alkali soil, heavy clay and sandy soil. , and adopt foreign soil or technical measures to improve soil according to the design regulations.
4, green space should be built according to the design requirements. Lawn planting area, flower planting area and sowing area should be fully fertilized with base fertilizer, ploughed for 25 ~ 30cm, raked and raked, and the flatness and slope should meet the design requirements.
(4) digging planting holes and planting grooves
1. Before digging planting holes and trenches, you should know the underground pipelines and buried objects of relevant units.
2, planting hole, slot fixed-point pay-off shall meet the following requirements:
(1) The fixed-point lofting of planting holes and grooves should meet the requirements of design drawings, and the positions must be accurate and clearly marked. Planting lofting positioning should be carried out before digging tree holes. Large-scale trees and shrubs with skeletons can be marked with inserted poles, and small shrubs and ground covers can be marked with white powder to determine the planting surface and forest edge line.
(2) When the planting hole is fixed, the position of the center point shall be marked. The planting trough should be marked with sideline and the marking line should be straight.
(3) The designated sign shall indicate the name (or code) and specifications of the tree species.
(4) When the fixed-point street trees encounter obstacles that affect the plant spacing, they should get in touch with the design unit and make appropriate adjustments.
3. The size of planting holes and ditches should be determined according to the root system of seedlings, the diameter of soil balls and soil conditions. Holes and troughs must be excavated vertically, and the upper and lower parts are equal, and their specifications shall comply with the provisions in Table 4.3-L ~ 5.
Evergreen tree planting hole specifications (cm) Table 4.3- 1
Tree height, soil ball diameter, planting hole depth, planting hole diameter
150 40-50 50-60 80-90
150-250 70-80 80-90 100- 1 10
250-400 80- 100 90- 1 10 120- 130
Over 400 140 120 180.
Note: In addition, the size of tree holes should be treated differently according to the different living habits of each tree species. The shape of the tree hole is cylindrical, requiring straight walls and flat bottom. When excavating, the surface soil and the core soil are placed separately.
Specification of planting holes for deciduous trees (cm) Table 4.3-2
DBH planting hole depth planting hole diameter DBH planting hole depth planting hole diameter
2-3 30-40 40-60 5-6 60-70 80-90
3-4 40-50 60-70 6-8 70-80 90- 100
4-5 50-60 70-80 8- 10 80-90 100- 1 10
Hedge planting tank specifications (cm) Table 4.3-3
Seedling height, seedling depth and seedling width are planted in single row and double row.
50-80 40×40 40×60
100- 120 50×50 50×70
120- 150 60×60 60×80
4, should be soaked before planting in dry soil areas. That is, planting and watering in the pit.
5. After digging and ditching, decomposed organic fertilizer should be applied as base fertilizer. The fertilizer should not directly touch the roots, that is, cover the fertilizer with soil.
(5) transportation and follow-up of seedlings
1, seedling transportation should be determined according to the planting amount. Seedlings should be planted in time after being transported to the site.
2. When loading and unloading the car, the seedlings should be hoisted lightly to avoid damaging the seedlings and causing scattered balls. Wrap a straw rope or other protective materials around the tree when hanging.
3. When the seedlings (platforms) are hoisted with soil balls, the soil balls shall be hoisted with rope nets, and the roots and necks shall not be tied with ropes for hoisting. Large-scale earth platforms with the weight exceeding 1t should be hoisted by steel cables outside the earth platform.
4, soil ball seedlings when loading, should according to the direction of the vehicle, soil ball forward, crown backward packed neatly.
5. When bare-rooted trees are transported for a long distance, the roots should be covered and kept moist. When loading, should be neatly packed; After loading, the trunk should be tied tightly and padded to prevent the trunk from being worn. If the roots are watered every 12 hour after long-term transportation, it is best to cover the roots with wet cloth.
6. Flowers and shrubs can be loaded vertically during transportation. When loading, it should be neat, and if there are soil balls, it should be wrapped up.
7. When loading bamboo, it is not allowed to damage the drop point and whip bud between the bamboo pole and the bamboo whip.
8. Root seedlings must be planted on the same day. The exposure time of bare seedlings shall not exceed 8 hours from the time of emergence. Seedlings that can't be planted that day should be planted.
9. After the small flowering shrubs with soil balls are transported to the construction site, the passwords should be placed neatly. If you can't plant it that day, you should sprinkle water to keep the soil ball wet.
10, precious tree species and seedlings that are not needed in the planting season should be cultivated in the appropriate season, and the following containers should be used.
1 1, be sure to water it after planting.
(6) Pruning before seedling planting
1. Before planting, the root system of seedlings should be trimmed, the cracked root, the root of diseases and insect pests and the excessively long root should be cut off, and the crown should be trimmed to ensure the balance between the ground and the ground.
2, tree pruning shall meet the following requirements:
(1) Tall deciduous trees with obvious trunks should keep their original tree shape and their branches should be properly drained. The main branches should be cut short on robust buds, and the branches can be cut from 1/5 to 1/3.
(2) For trees with trunk diameter of 10cm, thinning can be carried out for deciduous trees with no obvious trunk and dense branches to maintain the original tree shape; For seedlings with a trunk diameter of 5 ~ 10 cm, several lateral branches can be left on the trunk, and the original tree shape can be kept for short cutting.
(3) Evergreen trees with dense branches and round crown can be thinned appropriately. The seedlings at the top of the trunk with branches and leaves cannot be pruned. When evergreen trees with whorled lateral branches are used as street trees, 2 ~ 3 layers of whorled lateral branches at the base can be cut off.
(4) Evergreen conifers should not be pruned, only the branches of diseases and insect pests, dead branches, weak branches, over-dense whorls and drooping branches should be pruned.
(5) For trees used as street trees, the fixed dry height should be greater than 3m, all branches below the first branch point should be cut off, and branches above the branch point should be drained or chopped as appropriate, and the crown prototype should be maintained.
(6) The crown of precious tree species should be sparse.
3, shrub pruning shall meet the following requirements:
(1) Bare-rooted seedlings with soil balls or in wet areas and flowering shrubs with differentiated flower buds in the previous year should not be pruned, and dead branches and branches with diseases and insect pests should be cut off. The cut branches should be disposed of in time.
(2) Large shrubs with dense branches can be thinned appropriately.
(3) For grafted shrubs, the sprouting branches of the rootstock below the joint should be cut off.
(4) Shrubbery with obvious branches and new branches with flower buds should be strongly cut according to the tree potential to promote the growth of new branches and the regeneration of old branches.
(5) Trees and shrubs used as hedges can be pruned according to the design requirements after planting. Hedges formed by nursery cultivation should be renovated after planting.
4, seedling pruning quality should meet the following requirements:
(1) The incision should be smooth and not split.
(2) When the branches are cut short, the outer buds should be left, and the cut should be above the bud position 1cm.
(3) When pruning large branches and thick roots with a diameter of more than 2 cm, the section must be flattened and wrapped with preservatives or paint.
(7) Planting trees
1, according to the habits of trees and local climate conditions, choose the most suitable planting period for planting.
2. The planting quality shall meet the following requirements:
(1) The varieties, specifications and planting positions of seedlings should be checked according to the requirements of design drawings.
(2) Conventional planting should be balanced and symmetrical. Trees planted along the street or in rows and columns should be in the same straight line. The specifications of adjacent plants should be reasonably matched, and the height, trunk diameter and tree shape should be similar. Trees planted should be upright and not inclined. Attention should be paid to the reasonable orientation of the viewing surface and the suitable planting density.
(3) The row spacing of hedges should be even. The plump side of the tree should be outward and evenly matched according to the height of the seedlings and the size of the trunk. The hedges trimmed and formed in the nursery should be planted according to the shape, with the same depth.
(4) When planting trees with soil balls, the non-perishable packaging materials must be removed.
(5) Precious tree species should adopt measures such as spraying crown, keeping trunk moist and spraying root rooting hormone.
3. For planting holes with poor drainage, l0 ~ 15 cm gravel or seepage pipes and blind ditches can be laid at the bottom of the holes to facilitate drainage.
4. After planting trees, watering, supporting and fixing shall meet the following requirements:
(1) After planting, an irrigation weir with a height of 10 ~ 15 cm should be built around the hole slightly larger than the diameter of the planting hole, and the weir construction should be watertight. Fish scale pits can be planted on sloping fields.
(2) The newly planted trees should be watered for the first time on the same day, and then they should be replenished in time according to local conditions. Water it not less than three times after planting in the northern region.
(3) The cohesive soil should be properly watered, and the tree species with underdeveloped roots should be watered more; Fleshy root trees should be watered less.
(4) In dry areas or when the weather is dry, the watering frequency should be increased. In dry and hot wind season, the crown of newly sprouted long leaves should be sprayed before l0 in the morning and after 15 in the afternoon.
(5) When watering, it is necessary to prevent water from rushing through the exposed roots or destroying the cofferdam, causing water leakage. When the soil sinks after watering, which causes the trees to tilt, they should be righted and ridged in time.
(6) After water seepage, close the tree hole with cofferdam soil in time. When the weir is rebuilt, the root system shall not be destroyed.
(8) big tree transplantation
1, deciduous trees with DBH above 20cm and evergreen trees with DBH above 15cm should belong to big tree transplantation.
2. Before transplanting trees, the growth, site conditions, surrounding environment and traffic conditions of transplanted trees should be investigated and studied, and the transplanting technical scheme should be formulated. Mechanical transplantation can be used where conditions permit.
3. When transplanting big trees, the transplanting time should be determined one year ago. Before transplanting, the roots should be cut off by stages, trimmed and prepared for transplanting.
4, tree transplantation shall meet the following requirements:
(1) When transplanting trees, the main ornamental surfaces of the trees, as well as the shady and sunny surfaces of the trees should be marked.
(2) When transplanting big trees in general areas, soil balls or square soil platforms must be excavated according to 6 ~ 8 times of DBH of trees, and packaged.
(3) The machines and tools for hoisting and transporting trees must have bearing capacity. During shipment, the crown of transplanted trees should be tied and the trunk should be fixed to prevent damage to bark and soil balls (soil platforms). Pay attention to safety when operating.
(4) When unloading transplanted trees, the main ornamental surfaces should be properly arranged, and the soil balls (or boxes) should be directly hung in the planting holes, unpacked and compacted in layers.
(5) After the trees are transplanted, supports must be set to prevent the trees from shaking.
(6) After transplanting trees, full-time technicians should be provided to do a series of maintenance and management work such as pruning, bud peeling, spraying, foliar fertilizer, watering, drainage, wind barrier, shade shed, trunk wrapping, cold protection and insect prevention within two years. After confirming the survival of the big tree, it can enter the normal maintenance management.