Lagerstroemia speciosa

Lagerstroemia indica is robust and easy to cultivate, and has no strict requirements on soil, but it grows best when planted in deep and fertile sandy loam. Love the light, and should be planted in the lee or under the root of the south wall of the courtyard. If the light is insufficient, plants will not only spend less or not, but even grow weak and have small branches and leaves. Lagerstroemia indica is cold-resistant, but it should be well protected from cold and heat at seedling stage, and the adult plants over three years old do not need heat preservation. Lagerstroemia indica is drought-tolerant and afraid of waterlogging. Water it once a year before germination in spring and after defoliation in autumn. If it is not too dry at ordinary times, you don't need to water it. Drainage should be done well in rainy season to prevent water from rotting roots. Fertilization can be applied after defoliation in winter and before germination in spring every year, such as applying human manure or sesame paste residue, which can make plants grow vigorously and flowers big and colorful in the coming year. Generally, pruning should be carried out after defoliation in autumn, and long branches, dead branches, drooping branches, pests and diseases branches, slender branches and endogenous branches should be cut off in time during the young tree period, so that the upper part of the trunk can obtain sufficient nutrients and form a good crown.

Lagerstroemia indica is vulnerable to aphids, scale insects, spiny moths and leaf roller moths during the growth period. If it happens, dimethoate EC with 1000 times can be used to kill scale insects and aphids, and 80% dichlorvos EC with 1500 times can be used to kill spiny moths and leaf rollers.

The propagation of Lagerstroemia indica can be carried out by sowing, cutting and dividing plants, but the cutting method is the best, which not only has high survival rate, but also has fast plant formation, early flowering and high seedling rate. Cutting can be carried out in June. Select one-year-old robust branches with good lignification and no diseases and insect pests, cut and grow to about 15cm with sterile branches, cut off the lower leaves, leaving only two or three upper leaves, insert them into an intertillage sterile seedbed with a depth of about 10cm, and then cover them with plastic film and reed curtain for moisture and shade. Spray water 1 time every day after cutting, keep the humidity above 70%, and take root after 45 days. After the cuttings grow new buds, they are gradually illuminated, the plastic film is removed, and fertilization begins two months later. Cutting seedlings should be well protected from cold and heat when overwintering in seedbed, and can be transplanted and planted in April of the following year.

Reproduction management reproduction method

type

Lagerstroemia indica has graceful posture, smooth trunk, bright colors and long flowering period. Summer and autumn are sustainable 100 days. It is a good ornamental, which can be used to beautify courtyards, parks and green spaces, and can also be used for potted plants. Lagerstroemia indica likes sunshine, is slightly tolerant to shade, drought and waterlogging, and is strong in pruning. It grows well on calcareous soil and has strong cold resistance. Lagerstroemia indica can be propagated by sowing, cutting, layering, dividing plants, grafting and other methods.

Sowing propagation

A large number of healthy and tidy seedlings can be obtained at one time. Collect1October165438+February 65438+February mature seeds, remove the peel, slightly dry the seeds, and put them in a container for drying and preservation. In March of the following year, the sandy loam seedbed was planted with wide banners or spread, covered with a layer of fine burnt marl and covered with grass, so that no seeds could be seen. Germinate for more than 10 days, uncover the grass in time, and sow after the rain when two pairs of true leaves appear; Weed frequently at seedling stage, topdressing thin fertilizer 2-3 times in June-July, and irrigating in summer to prevent drought. The height of seedlings at the end of the year is about 40-50 cm. Flowers can bloom in the year of vigorous growth, so they should be cut off in time and transplanted and grown up in the spring equinox the next year.

cutting

Hardwood cutting and softwood cutting can be used.

Hardwood cutting is generally carried out in the middle and late March to early April before the branches germinate. Select stout annual branches, cut them into cuttings with a length of15cm, and insert them into a loose and well-drained sandy loam seedbed, and the cuttings are deep enough to expose the top buds of the cuttings. After insertion, it is filled with water and covered with plastic film to keep moisture and heat. When the seedlings grow to 15-20 cm, you can remove the film, put on the sunshade net and water them in time. The branches can grow to about 60-80 cm in that year.

Softwood cutting is carried out in July and August, when the new branches grow vigorously and have the most vitality. Select semi-lignified branches and cut them into cuttings of 8 ~ LOCM length, leaving 2 ~ 3 leaves at the top. The cutting depth is 3 ~ 4cm. After inserting, you can water it and shade it with a shade shed. Generally, it can take root in about 20 days. Remove the film, keep the sunshade net, and then water it in time. Branches can grow to about 60-80 cm in that year, and the survival rate is very good.

separate

Dig out the roots of tillering seedlings that germinate in the rhizosphere of plants in early March-April or autumn, properly prune the roots and branches, and plant them separately. Small seedlings can be bare-rooted, and big seedlings should carry mud balls. During the tending period, they should be pruned and trimmed frequently to maintain a beautiful tree shape and promote the flourishing of flowers and branches.

Stratified propagation

The growing season can be carried out, especially in March-April in spring. In the air layering method, branches of 1 ~ 2 years old can be selected, cut and girdled with a sharp knife to expose xylem, and rooting powder solution can be applied about 3 cm above the cut part (diluted according to regulations). When it is dry, put a cylindrical plastic bag around the cut part, fill it with loose garden soil, water it and tie it tightly at both ends, and check it after one month. If the soil is too dry, it can be hydrated and moisturized.

Grafting method

There are several varieties of Lagerstroemia indica, such as Yin Wei, whose flowers are white; Cuiwei, the flowers are blue-purple and lavender; Red, pink, crimson, etc. ; The author grafted several annual or biennial branches with different colors on the same tree, and the survival rate was over 98%. The specific method is: from late February to early March, before the branches of Lagerstroemia indica sprout. When grafting, the well-developed seedlings are selected as rootstocks, and the branches of the required color are used as scions, and the splitting method is adopted. First, the top of the rootstock near the peripheral part is split longitudinally with a knife about 5-8 cm deep, and then the scions of more than two buds with a length of 5-8 cm are cut into wedges and inserted into the split part of the rootstock to align with the cambium. Then wrap the whole spike with plastic film to expose the bud head. This method is used to graft branches of different colors on the same rootstock in layers to form multi-color trees. After 2-3 months of grafting, the membrane can be loosened. At this time, the length of the ear head can reach 50-80 cm. Branches should be cut short in time to avoid being broken by the wind and can be cultivated into thick branches. The survival rate of plants cultivated in this way is very good.

Specific practice: from late February to early March, before the branches of Lagerstroemia indica germinate. When grafting, the well-developed seedlings are selected as rootstocks, and the branches of the required color are used as scions, and the splitting method is adopted. First, chop a knife at the top of the rhizome near the peripheral part, about 5? 8 cm deep, and then take the length of 5? 8 cm scions with more than 2 buds were cut into wedges and inserted into the cracks of rootstock, aligned with the cambium. Then wrap the whole spike with plastic film to expose the bud head. This method is used to graft branches of different colors on the same rootstock in layers to form multi-color trees. Grafting 2? After 3 months, the membrane can be loosened and the length of the ear head can reach 50? 80 cm, the branches should be cut short in time to avoid being broken by the wind, and can be cultivated into thick branches. The survival rate of plants cultivated in this way is very good.

The author summed up the following conclusions from years of practice: among the five propagation methods, the color of seedlings cultivated by the latter four methods maintained the excellent performance of scions. However, there are many buds and branches produced by plant cutting and division, which need to be removed in time. If you need to practice to become a senior 3? For 6-meter trees, the seedlings propagated by sowing method are better, and the side branches produced are obviously reduced, but the colors of seedlings propagated by sowing method are easy to vary.

Cultivation management

Lagerstroemia indica should be planted in the leeward and sunny place with deep soil layer, fertile soil and good drainage. Large seedlings should be transplanted with the ball and the branches should be trimmed properly, otherwise the survival rate will be low. Apply decomposed organic fertilizer as base fertilizer in the planting hole, water it after cutting, and water it 1 time after 3 days. Lagerstroemia indica germinates late. Under normal circumstances, the leaves will only spread from mid-April to the end of April. Because of root injury, the germination of new plants will be delayed. So don't give up management just because you have no job.

After survival, the plant management is extensive, Lagerstroemia indica is strong and easy to cultivate, and the requirements for soil are not high, but it grows best when planted in deep and fertile sandy loam. Sex likes light, so it should be planted in the lee of the sun or under the roots of the south wall of the courtyard. If the light is insufficient, plants will not only spend less or not, but even grow weak and have small branches and leaves. Lagerstroemia indica is cold-resistant, but it should be cold-proof and heat-proof at seedling stage, and it is three years old.

The above adult plants do not need heat preservation. Lagerstroemia indica is drought-tolerant and afraid of waterlogging. Water it once a year before germination in spring and after defoliation in autumn. If it is not too dry at ordinary times, you don't need to water it. Generally, water l ~ 3 times in spring drought, and drain well in rainy season to prevent water from rotting roots. Autumn is not suitable for watering. Fertilization can be applied after defoliation in winter and before germination in spring every year, such as applying human manure or sesame paste residue, which can make plants grow vigorously and flowers big and colorful in the coming year. In order to make Osmunda bloom, pruning should be carried out during dormancy. Because the crape myrtle inflorescence is planted at the top of the new branches in that year, the annual branches should be pruned and retracted when pruning, so that the nutrients are concentrated and the branches are strong. Long branches, dead branches, drooping branches, pests and diseases branches, slender branches and endogenous branches should be cut off, and the side branches at the lower part of the trunk should be cut off in time during the young tree period, so that the upper part of the trunk can get enough nutrients and form a good crown.

Lagerstroemia indica cultivation and management are extensive, but it is necessary to cut off dead branches, pests and diseases in time and burn them. In order to prolong the flowering period, the branches that have blossomed should be cut off in time so as to germinate again and grow the next round of flowers. In order to make the trunk thicker, you can cut off many flowers and concentrate on cultivating the trunk. Practice has proved that with proper management, Lagerstroemia indica can bloom many times a year, reaching 100/ 120 days.

Stratification in winter and spring

The stratification time is generally 1 1 to February of the following year. First, dig a ditch with a depth of 20 cm to 30 cm in the whole nursery according to the row spacing of 40 cm, and apply 2 cm to 3 cm cow dung or horse manure as base fertilizer in the ditch. Combined with pruning in winter and spring, healthy plants with excellent varieties, bright flowers and no pests and diseases are selected as mother plants, and well-developed annual or biennial branches are adopted, with the required diameter of 1cm ~ 4cm and unlimited length. Soak in clear water for 2 hours, then bury it obliquely along the ditch, then cover the root firmly, and roll the upper part along the ditch, covering the soil 10 cm to 10 cm. In this way, it can germinate and grow in mid-March, and you can see the buds exposed on the ground in April. At this time, you can make a small arch shed again, cover it with plastic film and remove the grass. If the temperature in the shed exceeds 30℃, ventilate and cool down. From mid-March, the film should be uncovered and cultivated along the ditch once every 20 days, * * * 3 ~ 4 times, so that the base of the seedling will be changed from the original height to a ridge with a height of 10 cm, and a large number of adventitious roots will be produced. At the end of May, the arch shed will be demolished, and the seedlings will be pruned in sections according to the sprouting situation, and each sprouted seedling will become an independent seedling. At this time, it is necessary to top, promote the development of lateral branches, apply farmyard manure once, such as pancake fertilizer water or urea water, and then cultivate the soil along the ditch to promote growth. After that, it will be topdressing 3-4 times. If buds appear and become thinner in time, they will generally become full-crowned, leafy plants that year. After autumn, seedlings will emerge with soil in rainy days, so as to avoid damaging capillary roots as much as possible, and move to a place with sufficient sunshine and water and fertilizer for planting. After survival, water and fertilizer should be well controlled to enhance its adaptability. Comparatively speaking, under the same conditions, Lagerstroemia indica seedlings propagated by this method not only have developed roots, high transplanting survival rate, but also have better crown shape than other propagated seedlings. Through observation, many vines can also be propagated by this method, such as wisteria, Lingxiao, forsythia and so on.