When will the leaves of green transplanted trees be sprayed with water?

Matters needing attention in transplanting big trees:

1, transplanting date

It is best to transplant trees in dormancy, usually before germination in spring and after defoliation in autumn. The suitable transplanting time in northern China is spring.

2, the tree processing

The main contents of tree treatment include: root cutting, crown cutting and seedling storage in advance according to the difficulty of tree species transplantation. The purpose of pruning is obvious, mainly to maintain the balance of water metabolism in underground and aboveground parts of trees. Pruning strength should be analyzed according to the specific situation. The bigger the crown, the more exposed the root system, the more damaged the root system, the harder it is to take root, and the worse the season, the more pruning efforts should be made to minimize the transpiration area of the crown.

3, digging trees and packaging

Excavation and installation methods:

At present, the method of packing and transplanting soft materials by hand is widely used in China, which is suitable for excavating DBH 10 ~ 15cm round soil balls and evergreen trees.

Packaging method:

Pack with straw bag, straw or plastic woven material and straw rope (the trunk is wrapped with soaked straw rope to the branch point). There is also a wooden box packaging transplantation method, which is suitable for excavating DBH 15 ~ 25cm square soil platform and evergreen trees.

4, lifting and transportation

The hoisting of big trees is one of the important links of transplanting big trees, which is directly related to the survival of big trees, the construction quality and the perfection of tree shape. Tree transplantation is generally handled by crane and transported by car.

Step 5 plant trees

Before transplanting big trees, the soil in the cave should be disinfected and killed, that is, 50% Budweiser granules should be mixed with the soil to kill insects, and 50% thiophanate or 50% carbendazim powder should be mixed with the soil to kill insects in the same proportion. If conditions permit, some nutrient soil should be prepared in advance for use. The specific method is: take 50% sawdust, 30% plant ash and 20% cooked soil according to the weight ratio, fully mix them and leave them for 2-3 days to promote their high-temperature fermentation. Appropriate chemical fertilizer can also be added as needed. When transplanting formally, first spread a layer of nutrient soil at the bottom of the hole, then remove the dressing on the soil ball, and slowly move the big tree into the hole with the help of a crane, and pay attention to the direction when righting. When filling soil, backfill by layers, which is practical (nutrient soil should also be laid around and on the surface of soil balls). When the backfill soil reaches 2/3 of the height of the soil ball, water it for the first time 1 time, so that the backfill soil can fully absorb water, and then fill it after the water infiltrates (be careful not to be practical at this time). Finally, build a cofferdam on the periphery, water it for the second time and pour it thoroughly. After pouring water, pay attention to observe whether the soil around the trunk sinks or cracks, and if so, add soil to fill it in time.

6. Maintenance and management after transplantation

After transplanting big trees, we must strengthen the later maintenance management. As the saying goes: "three points in the world, seven points in charge", the truth covers.

For this reason. Judging from the main causes of tree death provided by various places, one of the most important ones is improper management in the later period, especially 1 year. Therefore, careful maintenance of transplanted trees should be regarded as an indispensable link to ensure the survival and healthy growth of transplanted trees, which should not be underestimated.

(1) setting support

After planting is completed, the trees must be fixed in time, that is, pillar support should be set to prevent the wet and soft trees in the ground soil layer from being tilted and dumped by the wind, which is beneficial to root growth. Generally, the triangular support method with three columns is adopted to ensure the stability of the tree. Old soles or straw bags can be used as spacers at the joint between the bracket and the bark to avoid grinding the bark. Usually, after 1 year, when the big tree root system recovers well, the support is removed.

(2) Water and water control

Trees should be watered immediately after transplanting 1 time to ensure close contact between roots and soil and promote root development. Generally, after planting in spring, according to the soil moisture, water should be poured every 5 ~ 7d and continuously for 3 ~ 5 times. The big trees transplanted in the growing period should shorten the interval and increase the watering times; In the case of particularly dry weather, further increase the number of watering.

(3) Ground coverage

Ground covering is mainly to slow down surface evaporation and prevent soil hardening, so as to facilitate ventilation. Usually, wheat straw, rice straw and sawdust are used to cover the tree tray, but the best way is to cover it with grass, that is, planting leguminous grass in the transplanting area, which not only improves the soil, but also inhibits weeds.

(4) keep the tree moist

The main methods include:

① Wrap the suitcase. In order to keep the humidity of the trunk and reduce the evaporation of bark water, the soaked straw rope can be wound from the root of the trunk to the top, and then coated with prepared mud, and then the straw rope is often sprayed with water to keep it in a wet state.

(2) Build a shade shed. In mid-April, the weather turned warmer, the temperature rose, and the evaporation of trees gradually increased. At this time, shade sheds should be set at the top of the tree in three directions (leaving the northwest for photosynthesis), and the distance between the top and the surrounding of the shade shed is about 50cm from the crown, which not only avoids direct sunlight and bark burns, but also maintains the air flow and the balance between supply and demand of water and nutrients in the shed. In order not to affect the photosynthesis of trees, 70% shading net can be used in the shade shed. After June 65438+ 10, the weather gradually turned cold, so the shade shed can be dismantled in time. Practice has proved that, if conditions permit, building a shade shed is the most effective measure to keep trees moist and vibrant during the growing season.

(3) Crown spraying. If the weather is fine after transplanting, you can use a high-pressure sprayer to spray water on the tree, 2-3 times a day, 1 week, 1 time a day, and15 days continuously. For famous trees and extra-large trees, water can be sprayed on the trees 1 time every morning and evening to humidify and cool down. In order to prevent the soil moisture content in the transplanting hole from being too high when trees are sprayed with water, plastic film should be covered on the tree tray.

④ Spraying inhibitor. Both Beijing Academy of Landscape Sciences and Shanghai Landscape Construction Co., Ltd. produce transpiration inhibitors, which can be used to transplant garden plants, and similar products from other manufacturers are also sold in the market. In addition, drought-resistant agents commonly used in agriculture (such as "Dryland Dragon") also have the effect of inhibiting plant transpiration.

(5) Transfusion promotion activities

Using the infusion method of internal water supply for planted trees can solve the contradiction between water supply and demand of transplanted trees and promote their survival.

(6) Fertilization and application of pesticides

After the transplanted trees grow new leaves, nitrogen fertilizer (preferably NPK compound fertilizer) can be applied with water, and the concentration is generally 0.2% ~ 0.5%. If the dosage of urea per plant is 0. 1 ~ 0.25 kg, apply fertilizer 1 ~ 2 times in the current year, and stop applying fertilizer in early September. As for foliar fertilizer, 1kg urea is dissolved in 200kg water, and the spraying time should be at 7 ~ 9 o'clock in sunny or cloudy days, and 17 ~ 19 o'clock. At this time, the leaves have strong vitality and good absorption ability.

(7) Adjust the tree shape

After the transplanted trees survive, they will grow a lot of branches. At this time, according to the characteristics of tree species and tree requirements, some unnecessary buds on trunk and main branches should be erased in time. After pruning, the tree can keep 3 ~ 5 stout main branches from different angles, and then keep 3 ~ 5 lateral branches on each main branch, thus forming a full crown and achieving an ideal landscape effect.