Introduction and information of Lagerstroemia indica

Lagerstroemia speciosa is a deciduous shrub or small tree of Lagerstroemia, also known as itch flower, itch tree, purple flower, purple orchid, mosquito flower, bayberry, zinnia, skinless tree and so on. Lagerstroemia indica has beautiful posture, smooth trunk and bright colors; It happens to be summer and autumn when it blooms, and the flowering period is long. Therefore, it is known as "Hundred Days Red" and "Summer Blue and White Flowers Full of Red". It is a good bonsai for ornamental flowers, stems and roots.

Lagerstroemia indica originated in the Yangtze River valley in China, and likes warm and humid climate, light, shade and fat, especially the deep and fertile sandy loam. It is suitable for growing on slightly moist land and is also resistant to drought and waterlogging. It is forbidden to plant in places with high groundwater level and low humidity. It is warm, cold-resistant and strong in germination. Lagerstroemia indica also has strong anti-pollution ability and strong resistance to sulfur dioxide, hydrogen fluoride and chlorine. Semi-shady, like to be born in fertile and humid soil, but also drought-tolerant, calcareous soil and acidic soil grow well.

1. Propagation methods of Lagerstroemia indica: The propagation methods of Lagerstroemia indica include sowing propagation, cutting propagation, grafting propagation, ramet propagation and layering propagation.

1. Sowing and propagation: The fruit sequence is autumn 9-165438+1October. When the capsule turns from green to brown, it can be picked, peeled, dried and stored, and planted in a ventilated and dry place in March-April of the following spring. Commonly used sowing methods are row sowing, furrow sowing or box surface sowing, and 2-3 seeds are sown every 3-4 cm. After sowing, it is covered with fine soil with a thickness of about 2 cm. It should be covered with soil without seeds. Cover with straw curtain or plastic film to keep the bed soil moist. After sowing, keep the seedbed temperature at 15-20℃. It can germinate and emerge in about 10- 15 days after sowing. After emergence, the mulch should be removed and the sunlight should be gradually accepted. Ensure soil moisture after excavation. After the seedlings grow two pairs of true leaves, they should be thinned. From June to July, the decomposed thin fat water should be applied for 2-3 times. Drought should be prevented in summer, and seedlings should be watered frequently. In that winter, the height of seedlings can reach more than 50 cm. Prune the lateral branches and flowering branches in time after defoliation in winter, and transplant them in early spring of the following year.

2. layering propagation: there are two methods of layering propagation of Lagerstroemia indica: low pressure propagation and high pressure propagation. Generally, low-pressure breeding selects 1-3-year-old branches in early spring, selects long branches to touch the ground, cuts the skin with a knife at the touched part, and presses the soil to keep moist. Always keep the soil moist after stratification. You can take root and sprout in a month or so and survive. After rooting, the mother plant is cut from the bottom of the hair root and planted as a new plant.

High-pressure layering, also known as air layering, is to choose 2-4-year-old branches that grow vigorously on the crown. At a distance of 20-30 cm from the base branch, one-half to two-thirds of the cortex is peeled off by annular peeling method, and then the wound is wrapped in a ball with fertilizer mud, and then wrapped in a plastic film to keep it moist. High pressure is usually carried out in February-March in early spring, and white roots can be seen growing through the plastic film from August to September, and then they begin to grow.

3. Plant-dividing propagation method: before germination in early spring or after defoliation in autumn and winter, the tillers germinated in rhizosphere are dug into several plants, or 2-3 shoots with roots are transplanted in clusters. After planting, water it thoroughly in time, pay attention to moisturizing, shade it when necessary, and water it when it is dry.

4. Cutting propagation: The common cutting propagation of Lagerstroemia indica can be divided into softwood cutting and hardwood cutting.

Softwood cutting: Softwood cutting is usually carried out in July and August. Select semi-lignified branches, cut them into cuttings with a length of 8- 10 cm, and leave 2-3 leaves at the top of the branches. The cutting depth is about 5-8 cm. Fill the cuttings with water, then cover a layer of plastic film on the cutting bed to build a sunshade net for shading, moisturizing and heat preservation. Generally 15-20 days can take root.

Hardwood cutting: Hardwood cutting is generally carried out from late March to early April before the branches germinate. One-year-old branches with strong growth were selected from well-growing mother plants and cut into branches with the length of 10- 15 cm and the pruning depth of about 10 cm. Irrigation with water after cutting, covering with plastic film after cutting, and covering with shade shed.

Plant growth hormone can be used to treat cuttings of Lagerstroemia indica, which has obvious effect on promoting rooting. Commonly used growth hormones, such as indolebutyric acid, indoleacetic acid, naphthylacetic acid, 2,4-D, rooting powder, etc. , have a good role in promoting rooting.

2. Cultivation: Lagerstroemia indica is mainly cultivated in the open field: when the seedling height is more than 50 cm, it can be planted around the courtyard dam. If it is continuous cropping, the spacing between plants should be about 4 meters, and it should not be planted too closely, so as not to affect ventilation. The cultivation of Lagerstroemia indica should choose soil with sufficient sunshine, high humidity, fertile soil, slight acidity (pH 6-6.5) and good drainage and ventilation. The row spacing of Lagerstroemia indica plants planted in the open field is 3m, and the row spacing is 4m. The planting pit is dug to a depth of 50cm, and decomposed farmyard manure is applied as base fertilizer. Before planting, the broken roots, broken roots, injured roots and excessively long roots of Lagerstroemia indica plants are cut off. First, fill the planting pit with fertile soil, and put the Lagerstroemia indica plants in the center of the planting pit to stand upright, and the roots should be stretched. When the soil is half filled, gently lift the crape myrtle plant and shake it, and compact the culture soil. It should not be too deep when planting, just keep the roots flush with the ground, and water them once after planting.

Third, management: cultivation of Lagerstroemia indica should also pay attention to fertilizer and water management, otherwise it will inhibit growth and affect flowering. In the hot summer and autumn season, Lagerstroemia indica grows and blooms, so we should pay attention to watering, and water it according to the principle of seeing dry and seeing wet. Drain in time in case of heavy rain to prevent root rot. Proper application of farm manure before germination and cultivation of fertile soil in roots after defoliation in autumn can promote growth. Fertilize once every 10 day from beginning of spring to beginning of autumn, topdressing once every half month after beginning of autumn, and stop fertilizing after beginning of winter. After defoliation in winter every year, appropriate pruning can promote the development of lateral branches. Keeping the soil loose, reducing water evaporation and promoting air circulation are very important to ensure the rapid and robust growth of Lagerstroemia indica plants. After the flowers wither, the residual flowers should be cut off in time, and the dead branches, weak branches, long branches and pests and diseases should be cut off.