Detailed Explanation of Key Techniques for Cherry Blossom Propagation and Cultivation

Propagation Methods Cherry blossoms are mainly propagated by grafting, and in a few cases by layering or cuttings, but the survival rate is relatively low.

Grafting mainly uses bud grafting and branch grafting. The rootstock is mainly cherry, but seedlings of Oshima cherry, Prunus itosakura, peach, apricot, etc. can also be used. If cherry is used as the rootstock, after harvesting the cherries, remove the flesh, wash them clean, and do not dry them in the air; stratify them in moist sand. If the seeds dry out, the germination rate will be affected. Sow in autumn or early spring of the following year. By autumn, the sturdy seedlings can be used as rootstock for bud grafting. After the bud graft takes, do not cut off the branch tip; wait until early spring of the following year before budding, then cut off the rootstock 2 cm above the grafted bud to encourage the grafted bud to sprout and grow. Branch grafting generally uses cut grafting or cleft grafting, carried out in March of spring before budding. Tests have shown that the cut grafting method has the highest survival rate.

Cultivation Management

I. Soil Requirements and Improvement Measures. When planting cherry blossoms, choose deep, fertile loam with good drainage. Places with particularly heavy air pollution are not suitable for planting. Cherry blossoms can grow well in sandy loam and clay loam containing more humus (pH 5.5-6.5). In southern areas where the soil is heavy and clayey, generally mix in homemade leaf mold (soil made by composting collected leaves with acidic soil, chicken manure, and charcoal powder). Note that before mixing, all existing soil clods must be broken up, otherwise the soil improvement effect will not be achieved.

In places where the groundwater level is less than 1 m, use the raised planting method, that is, level the entire planting hole first, then pile soil on top and plant the seedling. In northern regions with alkaline soil, adjust the pH to about 6 with sulfur or ferrous sulfate when needed. Apply 2 grams of sulfur powder per square meter, with a validity period of 1-2 years, and measure annually to keep the pH value from exceeding 7.

II. Planting Measures

1. Planting Time

Plant immediately after the soil thaws in early spring, generally in March.

2. Planting Method

Cherry blossoms are shallow-rooted trees, so when planting, the tree hole should be somewhat larger than for ordinary tree species to facilitate root spread. Carefully prepare the soil before planting. For planting on flat ground, dig a hole 1 m in diameter and 0.8 m deep. First fill about half the hole with improved soil, place the seedling in the center, and spread the seedling roots in all directions. After adding a small amount of soil, lift the seedling slightly upward so the root system spreads fully, then tread lightly. Maintain an appropriate spacing of 4-6 cm between plants so the trees receive sufficient sunlight. The planting depth should leave the uppermost seedling roots 5 cm from the ground surface. After planting, make a water basin and water thoroughly, finally supporting the tree with bamboo strips about the same height as the seedling to prevent it from being blown over by wind. When transplanting cherry blossoms, take more roots and a soil ball, and appropriately thin out the branches,

III. Management Measures

1. Drought Prevention

After planting, seedlings are prone to drought damage. In addition to thorough watering at planting, water once every 8 to 10 days thereafter, keeping the soil moist but without standing water. Loosen the soil promptly after watering, and preferably cover the ground surface with a thin layer of grass to reduce water evaporation. Within 2-3 years after planting, to prevent the trunk from drying out, it can be wrapped with straw. However, after 2-3 years, when the sapling grows new roots and its adaptability to the environment gradually increases, there is no need to wrap it with straw.

2. Management During the Growing Period

Cherry blossoms are fertilized twice a year, preferably with acidic fertilizers. One is winter fertilizer, applied in winter or early spring using organic fertilizers such as bean cake, chicken manure, and decomposed fertilizer; the other is after flowering, applying quick-acting fertilizers such as ammonium sulfate, ferrous sulfate, and superphosphate. For fertilizing generally large cherry blossom trees, the hole application method can be used, that is, dig a circular trench about 10 cm deep along the edge of the vertical projection line of the crown and apply the fertilizer into it. This method is both simple and conducive to root absorption. As the tree grows, the diameter and depth of the fertilizing circular trench should also increase accordingly.

Cherry blossom roots are shallowly distributed and require good drainage and aeration. Therefore, around the tree, especially within the root distribution range, people, livestock, and vehicles must never compact the soil. Trampling by pedestrians will weaken the tree's vigor, shorten its lifespan, and even cause root rot and death.

IV. Pruning and Maintenance

Pruning mainly involves cutting off withered branches, water sprouts, overlapping branches, and diseased or pest-infested branches. In addition, when many branches grow on the trunk of a generally large cherry blossom tree, several vigorously growing branches should be retained, and all the rest should be cut off from the base to facilitate ventilation and light penetration. After pruning, promptly disinfect the wounds on the branches with medication to prevent pathogens from invading after rain and causing rot. After long periods of exposure to the sun, the bark of cherry blossoms is prone to aging and damage, causing rot, which should be removed promptly and disinfected. After that, wrap the rotting area with leaf mold and charcoal powder to help it restore normal physiological function.