How to propagate flowering almond (Prunus triloba) by cuttings? A detailed guide to propagation techniques

  Flowering almond (Prunus triloba) is an important early-spring flowering tree species in the gardens of North China. Although it is robust by nature and easy to cultivate, spring care cannot be relaxed. If spring management is neglected, the tree will not grow vigorously and will not flower abundantly, affecting its ornamental effect. Flowering almond has been cultivated in China for several hundred years, and it is planted in most parks across the country.

  Flowering almond is also called xiaotaohong (little peach blossom), named because its leaves resemble elm leaves and its flowers closely resemble plum blossoms. It is a shrub or small tree, 2-3 m tall; the branches are spreading, with many short small branchlets; the branchlets are gray, and one-year-old branches are grayish brown, hairless or slightly pubescent when young; the winter buds are small, 2-3 mm long. The branches are purplish brown, and the leaves are broadly elliptic to obovate, with a 3-lobed apex and irregular coarse heavy serrations along the margin; the flowers are single to double, purplish red, 1-2 borne in the leaf axils, with a flowering period in April; the drupe is red, nearly spherical, and hairy.

  As an important early-spring flowering tree species in the gardens of North China, although it is robust by nature and easy to cultivate, spring care cannot be relaxed. If spring management is neglected, the tree will not grow vigorously and will not flower abundantly, affecting its ornamental effect. Softwood cuttings are usually taken from the current year's branches in late spring and early autumn, or hardwood cuttings are taken from last year's branches in early spring.

  Cutting medium: This refers to the nutrient soil, river sand, peat soil and other materials used for cuttings. For home propagation, it is difficult to obtain an ideal cutting medium due to limited conditions, so it is recommended to use a pre-mixed and sterilized cutting medium; medium-coarse river sand can also be used, but it should be rinsed several times with clean water before use. Do not use sea sand or river sand from saline-alkali areas, as they are not suitable for the growth of flowering plants.

  Selection of cutting branches: When taking softwood cuttings, choose vigorous current-year branches as cuttings during the period of vigorous growth from late spring to early autumn. After cutting the branches off, select the sturdy parts and cut them into sections 5-15 cm long, each section bearing more than 3 leaf nodes. When cutting the cuttings, note that the upper cut should be made horizontally about 1 cm above the topmost leaf node, and the lower cut should be made diagonally about 0.5 cm below the bottommost leaf node; both the upper and lower cuts should be smooth (the knife must be sharp). When taking hardwood cuttings, after temperatures rise in early spring, select vigorous branches from the previous year as cuttings. Each cutting usually retains 3-4 nodes, and the cutting method is the same as for softwood cuttings.

  [Management after cutting]

  Temperature: The optimum temperature for cutting rooting is 20°C-30°C. Below 20°C, the cuttings root with difficulty and slowly; above 30°C, the upper and lower cuts of the cuttings are easily infected by pathogens and rot, and the higher the temperature, the greater the proportion of rot. When low temperatures occur after cutting, the main measure for keeping warm is to wrap the flowerpot or container used for cuttings with plastic film; when the temperature is too high after cutting, the main measure for cooling is to shade the cuttings, blocking out 50-80% of sunlight, and at the same time mist the cuttings 3-5 times a day; on sunny days with higher temperatures, mist more often, while on cloudy and rainy days with lower temperatures and higher humidity, mist less often or not at all.

  Humidity: After cutting, the relative humidity of the air must be maintained at 75-85%. The basic requirement for cutting rooting is that before the cuttings root, they must be kept fresh and tender so they can carry out photosynthesis to produce rooting substances. However, cuttings that have not yet rooted cannot absorb enough water to maintain their internal water balance. Therefore, misting must be used to reduce water evaporation from the cuttings: under shaded conditions, mist the cuttings 3-5 times a day; on sunny days, the higher the temperature, the more frequent the misting, while on cloudy and rainy days, the lower the temperature, the less frequent the misting or none at all. However, excessive misting makes the cuttings prone to infection by pathogens and rot, because many kinds of pathogens exist in water.

  Light: Cutting propagation cannot do without sunlight, because the cuttings still need to continue photosynthesis to produce nutrients and rooting substances to supply their rooting needs. However, the stronger the light, the higher the temperature inside the cuttings, the more vigorous the transpiration of the cuttings, and the more water they consume, which is unfavorable for the survival of the cuttings. Therefore, after cutting, 50-80% of sunlight must be blocked, and after the root system grows out, gradually remove the shade net: on sunny days, remove the shade net at 4:00 pm each day and cover it again before 9:00 am the next day.