What are the maintenance methods for Acer palmatum?
Today, I will explain the maintenance methods for Acer palmatum and the management points of planting Acer palmatum in the aspect of green plants and flowers. Next, let's introduce.
Acer palmatum Introduction
Acer palmatum Thunb, also known as Japanese maple, belongs to the Aceraceae family, Acer genus, deciduous small trees or trees. The crown is umbrella-shaped with graceful posture. The bark is smooth and the young branches are red-brown. The leaves are opposite, palmately lobed with 7-9 lobes, the base truncate or heart-shaped, the lobes acuminate, the margins irregularly sharp-toothed or doubly sharp-toothed, young leaves densely pubescent, and old leaves smooth and hairless. In autumn, the red leaves are like brocade, very pleasing to the eye. The flowers are mixed, composed of purple-red small flowers in corymbs, blooming in April. Samaras spread into obtuse angles, curve upwards, and mature in October, turning brownish yellow.
Major varieties and cultivars include: Red Maple, with purple-red branches and palmately lobed leaves that remain purple-red throughout the year; Feathery Maple, with spreading and drooping branches, leaves palmately deeply lobed 7-11 times, with wrinkled lobes; and Weeping Acer, with smaller leaves, palmately deeply lobed 7 times, base cordate, apex long acuminate, samaras short and small.
1. Propagation
Acer palmatum is commonly propagated by seed, while Red Maple and Feathery Maple are propagated by grafting.
(1) Seed Propagation
Using seed propagation, its varieties are grafted. Seeds are collected in October, slightly dried to remove wings, and can be sown in autumn or stratified in moist sand. Spring sowing is carried out in February, sown in drills, covered with 1cm of soil, and mulched with straw. Sowing rate is 60-75 kg/hm2. Seedlings emerge in late March, and to prevent sunburn, they need short-term shading in July-August, watered to prevent drought, and annual seedlings can reach a height of 30-50cm. The following spring, they are transplanted to cultivate large seedlings, and after two years, they are transplanted again according to greening needs to cultivate different specifications of seedlings.
During the seedling stage, attention should be paid to watering to prevent drought and applying dilute top dressing to promote growth.
(2) Grafting
For horticultural varieties, grafting is commonly used. Using Acer palmatum seedlings as rootstocks, branch grafting is carried out in spring, and young branch grafting is done during the plum rain season. Both rootstocks and scions are selected from annual semi-woody branches, using a high-branch multi-head grafting method to promote the early formation of a round crown.
Taking Red Maple as an example, the key points of grafting technique include: selecting healthy rootstocks and scions, using 2-3-year-old Acer palmatum or Acer truncatum seedlings with a ground diameter of 1-1.5cm, and selecting one-year-old Red Maple branches as scions. The timing and method of grafting should be mastered. Grafting is done from mid-March to mid-April (slightly different depending on the region and phenology), before the sap flow, cutting the Red Maple branches into 6-7cm long with 2 full buds at the top, quickly dipped in melted paraffin wax to coat the epidermis with a thin layer of wax, then placed in a plastic bag and stored in a moist and low-temperature place for later use before the rootstock sprouts. The grafting method uses cleft grafting or approach grafting. Generally, the graft union can heal in about 25-30 days, and the rootstock sprouts should be removed in time. After survival, the binding should be loosened and re-tied or earthed up to prevent wind damage, then enhanced fertilization and water management.
2. Management
Seedling transplantation should be done in a shaded, moist, and fertile area, after the leaves fall in autumn or before sprouting in spring. Large seedlings must be transplanted with soil. For those with red autumn leaves, they need sufficient sunlight in summer and fertilized and watered, and it is better to keep the soil dry in autumn. If the fertilizer is insufficient, after frost in autumn, apply 1-2 times of nitrogen fertilizer and prune appropriately to promote the growth of new leaves. When the leaves turn red, move them indoors for maintenance, not only will the leaf color be bright, but it can also extend the ornamental period.
The main pests of Acer palmatum include刺蛾 (spiny caterpillar), 大蓑蛾 (large bagworm moth), 蚜虫 (aphids), and 星天牛 (star longicorn), and they should be controlled in a timely manner. Diseases include rust, powdery mildew, white纹羽病 (white feather disease), and brown spot disease, and these should also be paid attention to and controlled.
3. Uses
Due to Acer palmatum's graceful posture and beautiful leaf shape, its red autumn leaves, plus the variety of species, it is a valuable ornamental native species in gardens. In landscape greening, different varieties are often combined to form a colorful Acer garden; mixed with evergreen trees to create a "touch of red in a sea of green" landscape; planted on the mountainside or by the pond to show its graceful and elegant charm; combined with rocks for an ancient interest. Additionally, it can be planted in flower beds as a main景 tree, on both sides of the garden gate, corners of buildings, decorating the scenery; and used as a potted plant for indoor beautification, which is also very elegant.
4. Maintenance Management
(1) Placement
Acer palmatum should be placed in a well-ventilated, warm, and humid area. In summer, it should be appropriately shaded to prevent exposure to the scorching sun. However, for those with red autumn leaves, they need sufficient sunlight in autumn to turn red. In winter, it can be placed indoors to prevent the potting soil from freezing.
(2) Watering
Usually, it is necessary to keep the potting soil moist, especially during the leafing period, it should not be too dry. In autumn, when the leaf color turns red, the potting soil should be slightly dry. Watering in summer should be done in the morning and evening to avoid sudden changes in soil temperature, affecting root physiological functions. In autumn, it should be slightly dry.
The above is the specific content about the maintenance methods for Acer palmatum and the management points of planting Acer palmatum, for everyone's reference and operation.