Detailed Explanation of Ornamental Peach Propagation and Cultivation Techniques
Ornamental peach, also called peach blossom, refers to peach tree varieties grown for ornamental purposes. Compared with fruit peaches grown for eating, it has larger flowers, more petals, more graceful flower shapes, richer colors, and a longer flowering period. Except for a few varieties, ornamental peach generally does not bear fruit; even if it does, the fruit is inedible, poor in color, and small. But its bright and brilliant flowers are a symbol of spring and an indispensable flowering plant for spring viewing. The Tang dynasty poet Du Fu once used the line "A cluster of peach blossoms blooms unattended, how lovely the deep red sets off the pale red" to describe its lushness and beauty.
Ornamental peach can be planted as a solitary specimen, in groups, or in rows in courtyards, squares, roadsides, and near buildings. It can also be interplanted with willow trees to create the effect of "red peach and green willow"; it can also be grown in pots for ornament or made into bonsai. In addition, it can be used as cut flowers for vase arrangements.
I. Basic Morphology
Ornamental peach is a deciduous small tree in the genus Prunus of the rose family. It can be divided into two major lines: the mountain peach line, which is the result of hybridization between peach and apricot or between peach and mountain peach; and the true peach line, which is pure peach. These two major lines are further divided into five types. Except for the white mountain peach type, which belongs to the mountain peach line, the broom peach type, the longevity peach type, the weeping peach type, and the upright-branch peach type all belong to the true peach line. The flower shapes of ornamental peach can be divided into 5 types: single form, with 5 petals and a relatively flat flower shape; plum form, with 20 to 25 petals and a flower shape like plum blossom; rose form, in which after the flower opens the outer ring of petals curls outward while the inner ring wraps inward, like a small rose; peony form, with more than 40 petals, the whole flower like a flower ball, quite like a peony; and chrysanthemum form, with slender and numerous petals, resembling a chrysanthemum in appearance. Among ornamental peaches, the most commonly cultivated and richest in varieties is the double pink peach.
Double pink peach (Prunus persica f. duplex), also called flower peach or thousand-leaf peach blossom, is the general term for double-flowered and semi-double-flowered ornamental peach types. The plant height is about 8 m, and after shaping it can be controlled at 3 to 4 m, or even shorter. The branchlets are reddish brown or greenish brown and hairless; the buds have gray down; the leaves are elliptic-lanceolate, 7 to 10 cm long, with acuminate tips and fine serrate margins; the petioles have glands; and in addition to ordinary green, the leaf color also includes purplish red. The flowers are solitary or 2 together in the leaf axils, opening at the same time as the leaves or slightly earlier. Its flower colors are delicate and gorgeous, including white, pink, scarlet, deep red, and purplish red. Some varieties can even produce flowers of different colors on the same plant, the so-called "sporting-branch peach," and even a single flower can have spots or streaks of two different colors, which is called "sprinkled-gold double pink peach."
There are many varieties of double pink peach. Common ones include sprinkled-gold double pink peach, longevity double pink peach, weeping double pink peach, red-flowered double pink peach, purple-leaf double pink peach, pagoda-shaped double pink peach, white-flowered double pink peach, thousand-petal double pink peach, two-colored double pink peach, five-colored double pink peach, and human-face peach.
The flowering period of ornamental peach varies by region. In warmer areas such as Guangdong and Guangxi, it can bloom around the Spring Festival or even earlier, while in colder northern areas it does not bloom until April to May.
II. Propagation Methods
Ornamental peach propagation is mainly by grafting. One-year-old seedlings of wild peach, mountain peach, or apricot can be used as rootstock, and one-year-old shoots sprouting from old peach tree stumps grown for many years can also be used as rootstock. The scion uses branches or buds of superior ornamental peach varieties. To increase ornamental value, different ornamental peach varieties can also be grafted onto one plant so that it produces flowers of different colors and flower shapes.
1. Cleft grafting, also called branch grafting, is carried out before sprouting in spring. The scion uses vigorous and well-developed branches grown in the previous year, and the rootstock should be about 1.2 cm thick. Cut off the branches above ground, split a small slit from the middle of the rootstock, and cut the lower end of the ornamental peach scion into a slanted surface with a sharp knife so that it fits together with the slit in the rootstock. Then tie it firmly with plastic twine, mound soil over it, and do not expose it to wind or sunlight. Growth can resume in about one month.
2. Bud grafting. This is the most commonly used propagation method for peach. It is carried out from May to August each year. The rootstock should be smooth and sturdy, about 1.5 cm in diameter. Select buds from the middle section of well-developed current-year branches of superior peach varieties as scions. When choosing buds for grafting, select relatively pointed leaf buds, because only such buds can sprout shoots smoothly after grafting and survive; round, plump buds with more white silky hairs are flower buds and cannot be used.
When grafting, first make cuts above and below the scion bud with a sharp knife, then make two vertical cuts on the back of the bud, and use force to lift out a 0.3 cm thick piece of bark, called the "pattern." Then, according to the size of the "pattern," remove a bud piece in the same way at the vigorous bud site on the rootstock, and fit the bud piece from the scion onto it. The bud on the scion can also be cut into a "T" shape, and the rootstock can also be cut with a "T"-shaped incision, then insert the grafted bud into the incision so that they fit each other.
Finally, tie it from top to bottom with hemp cloth or plastic twine, leaving only the petiole and bud exposed. The tying should not be too tight, so as not to damage the bud piece. If the color of the bud remains unchanged after 10 days, it indicates that it has survived.
3. Management after grafting. For plants that survive grafting, promptly remove new buds sprouting on the rootstock and cut off branches on the rootstock. For bud-grafted plants, when the grafted bud has sprouted shoots about 10 cm long, cut the rootstock off 1.5 to 2 cm above the grafted bud. These measures are all intended to prevent branches on the rootstock from dispersing nutrients and to promote the growth of the scion.
III. Cultivation Management
Ornamental peach originated in China and is distributed in the provinces of North China, Central China, and Southwest China, and has been introduced and cultivated in countries around the world. Ornamental peach likes a warm, humid environment and full sunlight. It is cold-resistant but afraid of waterlogging. It is suitable for growing in loose, fertile, well-drained sandy soil, and dislikes alkaline soil and heavy clay soil.
Ground planting. Ground-planted ornamental peach can be planted in sunny, well-ventilated places. It can be planted on embankments, sunny slopes, lawns, roadside green belts, residential communities, courtyards, and other places, but it is not suitable to plant it under large trees with broader crowns, so as not to affect ventilation and light penetration, nor in low-lying waterlogged places, so as to avoid root rot caused by standing water.
1. Transplanting. Ornamental peach is transplanted in early spring or after leaf fall in autumn with a soil ball. For young trees, a soil ball is not necessary, but the roots should be coated with mud slurry. When transplanting large trees, a soil ball must be used to increase the survival rate. The planting hole should be dug slightly larger, and fully decomposed farmyard manure, cake fertilizer, and the like should be applied as base fertilizer. After planting, water thoroughly once. For peach trees with larger crowns, support frames should be used after planting to fix them, so as to prevent the plants from swaying back and forth in strong winds and adversely affecting later survival and growth.
2. Watering. For ground-planted ornamental peach, it is enough to water once each in early spring and late autumn with thawing water and freezing water respectively.