Planting technique of Forsythia suspensa

Forsythia, also known as Huangshou Dan, Huanghua Pole, Yellow Ribbon, Ribbon Dan, belongs to the genus Forsythia of Oleaceae. It is produced in the northern, central and northeast provinces of China, and now it is cultivated in many places. Forsythia suspensa blossoms all over the trees in spring, and its golden branches sway with the spring breeze. It is an important flowering shrub in early spring. The following editor will introduce the planting techniques of Forsythia suspensa for reference.

Growth habits of Forsythia suspensa

Forsythia likes light, has a certain degree of shade tolerance; likes warm, humid climate, but also very cold-resistant; resistant to drought and barren, afraid of waterlogging; regardless of soil, it can grow normally in neutral, slightly acidic or alkaline soil.

It can grow on dry sunny slopes or earthy stone crevices, or even on the weathered parent material of bedrock or purple sand shale. Forsythia suspensa root developed, although the main root is not significant, but its lateral roots are thick and long, many whisker roots, widely extended around the main root, greatly enhanced the ability of absorption and soil consolidation; Forsythia suspensa has strong cold resistance, after cold resistance exercise, it can withstand-50 ℃ low temperature, its amazing cold resistance makes it become a leader in northern landscaping; Forsythia suspensa has strong germination and fast hair clumps, which can quickly expand its distribution. Therefore, Forsythia suspensa has strong vitality and adaptability.

According to the experiment, Forsythia suspensa can grow normally in the areas with altitude 250m-2200m, average temperature 12.1℃-17.3℃, absolute highest temperature 36 ℃-39.4℃, absolute lowest temperature-4.8℃-14.5℃, but it grows better under sunny, deep, fertile and humid site conditions.

Propagation techniques of Forsythia suspensa

Forsythia can be propagated by seed, cuttage, striping, plant division and other methods, and seed and cutting propagation is the main method in production.

1. Seed propagation

① seed collection: the dominant mother plant should be selected. The dominant single tree with strong growth, short and sturdy branches, dense and full flowers and fruits, no diseases and insect pests and pure varieties was selected as the mother tree. Pay attention to observe the period of flowering and fruiting, and grasp the appropriate time to collect seeds. It should be collected in time to avoid the seeds falling off after maturity. Ripe fruits are generally collected from mid-September to early October. Forsythia fruit with mature, full, large and heavy grains should be picked, then spread thinly in a ventilated and cool place, and threshed after drying. After careful selection to remove miscellaneous, select neat, full and disease-free seeds, storage and retention of seeds.

② seed storage: the seed of Forsythia suspensa was stored under different conditions, which had a great effect on its germination rate. Beijing scientific research institutions collected forsythia seeds in 1977 and stored them in chicken heart bottles at room temperature. By February 26, 1979, the germination rate was 43.7%. According to the experiment of Hainan Drug Station, the seeds of Forsythia suspensa are better stored by dryer. After 11 months of storage, the seedling emergence rate can still reach 85.3%. When it is used for sand storage for 7 months, the seedling emergence rate is reduced to 31.3%, and the germination power is completely lost after more than 8 months of storage. When the seeds were stored with damp sand, the seeds germinated one after another, so the seedling emergence rate in the later stage of sowing was not as high as that in the dryer.

③ seed germination: forsythia seeds are easy to germinate, so it should be said that seeds are suitable for germination at higher temperatures. According to the seed storage and germination, combined with practical experience, the cultivation time can be arranged in spring or winter, spring sowing in the first and middle of April, and winter sowing before freezing.

④ seed seedling: the seed coat of Forsythia suspensa seed is hard, without pretreatment, direct seeding nursery, it takes more than one month to germinate and unearth. Therefore, budding treatment can be carried out before sowing. This method can be used in new introduction areas. The specific method is as follows: select mature and full seeds, soak them in about 30 ℃ of warm water for about 4 hours, remove them, mix them with wet sand and pack them in wooden boxes or small vats, cover them with plastic film, place them in the leeward and sunny place, turn them twice a day, and often keep them moist. After more than 10 days, the seeds germinate and can be sowed. The seedlings can emerge 8-9 days after sowing, and about 20 days earlier than the seeds without pretreatment. If the land is dry, first water the border, and sow seeds when the topsoil is slightly loose. Spring sowing before and after the Qingming Festival, and winter sowing before freezing (seeds do not need to be treated, seedlings can emerge the following year).

⑤ seed sowing: when sowing seeds on the whole border surface, according to the row spacing of 20ml 25cm, open a ditch 1 cm deep, mix the seeds with fine sand, spread them evenly into the ditch, cover the soil flat, and slightly suppress. The seedlings can be unearthed in 10-15 days. The amount of seed used per mu is about 2-3 kg. Cover the soil should not be too thick, generally about 1 cm, and then cover the grass to keep moist. After the seeds were unearthed, the grass was unearthed immediately. When the seedling height is 10 cm, the seedling is fixed according to the plant distance of 10 cm, and when the seedling height is about 30 cm in the first ten days of April of the following year, it can be transplanted in the field.

⑥ field direct broadcast: open holes according to row spacing of 2m and plant spacing of 1.5m, apply compost and plant ash, and mix with soil. Sowing begins from late March to early April, and can also be sown before the soil is frozen in late autumn. Sow more than 10 seeds in each hole, cover the soil after sowing, and press lightly. Be careful to sow when the soil moisture is good.

2. Striping propagation

Striping propagation is that the drooping branches of the plant are buried in the soil in spring and cut off from the mother plant in the following spring. Generally, cuttage propagation is the main method, and seedlings should be planted on fertile soil with sunny and good drainage. If the land is not selected properly and the soil is barren, the growth is slow and the yield is low. Withered branches, weak branches and over-dense and over-old branches should be cut off every year after flowering. At the same time, pay attention to rhizosphere fertilization.

3. Cuttings propagation

Cuttings can be cut after defoliation in autumn or before sprouting in spring, but it is better in spring. Select 1-2-year-old sturdy twigs and cut them into cuttings that are 30 cm long. The top cut should be 0.8 cm away from the first node. Each cuttings must have 2-3 nodes. Then the lower end of the joint is cut into a plane. In order to improve the survival rate of cuttings, the cuttings could be divided into 50 roots and a bundle, soaked in 500ppmABT rooting powder or 500-1000ppm indole butyric acid solution for 10 seconds, and dried.

In the south, there are more cuttings in the open field in early spring, while in the north, the cuttings are more in summer. Before cutting, rake the seedling bed fine and flat, make a high border, 1.5 meters wide, according to the row spacing of 20 × 10 cm, obliquely insert into the border, insert 18-20 cm deep into the soil, expose the uppermost section of the branch to the ground, and then bury the soil for compaction, and often water the soil during drought to keep the soil moist, but not too wet, otherwise the cuttings will blacken and rot. Under normal management, the seedling rate of cuttings can be as high as 90%. To strengthen field management, the height of seedlings can reach more than 50 cm after autumn, and can be planted in the following spring.

4. Ramet propagation

After "Frosts Descent" or before sprouting in spring, the young strips that occurred next to the trees for more than 3 years were dug out with soil for transplanting or the whole tree was shaved out for transplanting. Generally, a plant can be divided into 3-5 plants. The key to using this method is to make each small plant with a little fibrous root, so that the survival rate is high and the effect is quick.

Planting techniques of Forsythia suspensa

Before planting forsythia, fertilize in the hole first, apply rotten stable fertilizer or soil miscellaneous fertilizer and appropriate amount of compound fertilizer in each hole (see soil selection and soil preparation). When planting, the root system of the seedling should be stretched, layered and solid, and the soil cover at the planting point should be higher than the hole surface, so as to avoid the cave soil sinking after rain, which is not conducive to survival and growth. In order to overcome the self-flowering sterility of the same plant of Forsythia suspensa and improve the pollination rate, the planting points of long-style flowers and short-style flowers must be arranged reasonably. According to relevant reports, the fruiting rates of these two different types of flowers growing in different environments at the same time are very different. Under the condition of interphase cultivation (interrow mixing), the fruiting rate was 63.9%. In the plots with more fruit under natural conditions, the fruiting rate was only 47%. Therefore, if the same cultivation is changed to inter-plant mixed planting, the fruiting rate is higher, because the long-styled flower plants and short-styled flowers are surrounded by each other, and pollination is less affected by wind direction, slope direction, uphill and downhill than inter-row mixed pollination, which can obviously improve the pollination rate.

When forsythia was mixed, the configuration of two adjacent long-style plants and short-style plants were different, and they should be staggered up and down, that is, the plants with single-row, double-row and double-row configuration were the same. Except for the florescence, it is difficult to distinguish between the long-styled and short-styled plants of Forsythia suspensa, especially the seedlings. In order to meet the needs of production, it can be propagated by cutting, pressing and dividing plants respectively when it blossoms, mainly by cutting, because of its wide source of propagation materials, high utilization rate and high propagation coefficient, which can meet the needs of afforestation. As a result, the problem of insufficient seedlings in mixed planting of two different types of flower plants can be solved.

1. Water and fertilizer management

Forsythia is drought-resistant and likes a humid environment. Watering management should be strengthened in the first three years of planting. In addition to watering the first three water, Forsythia suspensa should also be watered 1-2 times a month according to temperature and precipitation from April to September. July and August are abundant periods of precipitation. The weather is not particularly dry. Water may be watered less or not, and antifreeze water should be watered thoroughly at the end of November or early December. In the following year, thawing water should be well watered at the beginning of March, watering should be controlled during flowering, permeable water should be watered once when new leaves germinate after flowering, and 1-2 times should be watered according to air temperature and precipitation from April to September. The third year should also be managed according to the watering method of the first two years. From the fourth year, thawing water and antifreeze water will be poured at the beginning of March and the end of November every year. During the high temperature period in spring and summer, the water will be watered according to the precipitation, and it will grow in reliable days at other times.

Forsythia likes to be fat, with luxuriant branches and leaves and large and colorful flowers. To fertilize Forsythia suspensa, in addition to applying sufficient base fertilizer when planting, we should also apply dried chicken manure or sesame sauce residue at the end of autumn combined with anti-freezing water, apply nitrogen fertilizer once after flowering in the second year, apply phosphorus and potassium compound fertilizer once during flower bud differentiation in July and August, and apply dried chicken manure again at the end of autumn, and then manage it according to this method every year.

2. Pruning method

The common plant type of Forsythia suspensa is tufted round head. After the seedlings are planted, the selected main branches are heavily truncated to promote its branching. When pruning in winter, thin and weak branches and roots and tillers sprouting from the rhizome should be removed. For the weak thin and curved branches, the full length of 1x5 can be cut off, only the full flower buds in the branches can be retained, 3-4 erect long flower branches which are heavier at the top of the growing branches can be slowly released, and the rest of the overlong flower branches can be treated by retraction; for long branches, they can be truncated to promote their multiple branches, increase flowering branches, and can also be reserved as regeneration branches.

In addition, Forsythia can also be cut into an umbrella, this plant type in the blooming season breeze blowing, very elegant and free and easy, often used to decorate rocks and so on. When planting, one of the strongest branches is cut short at 40-50cm from the ground, and the rest of the branches are thinned out. The new branches are drawn from the top of the left trunk, and 3-4 branches with more uniform distribution and suitable opening angle are selected as the main branches, and the rest are all thinned, and the remaining main branches are cut short to make more side branches, because the forsythia branches are soft and easy to droop, thus making them into an umbrella shape. After the umbrella shape is basically formed, the roots and tillers should be often removed, the branches should also be removed frequently, and the side branches that are too dense should also be removed to make them ventilated and transparent.

3. Pest control

The common disease of Forsythia suspensa is leaf spot, which is caused by semi-known fungi. The pathogen first infects the edge of the leaf, gradually develops to the middle of the leaf with the development of the disease, distinguishes the health part obviously, and the whole leaf wilts and dies in the later stage of the disease. The disease began to occur in mid-late May and reached its peak in July and August. the high temperature and humidity weather and dense ventilation were conducive to the spread of the disease. To prevent and cure leaf spot disease, one is to pay attention to pruning, to remove jumbled branches and over-dense branches, to keep the plants ventilated and transparent, and the other is to strengthen water and fertilizer management, pay attention to nutrition balance, and not apply nitrogen fertilizer. In case of occurrence, the disease can be effectively controlled by spraying 1200 times of 75% chlorothalonil wettable granules or 50% carbendazim wettable granules every 10 days for 3-4 times.

The common pests of Forsythia suspensa are: wide-winged wax cicada, transparent sparse wax cicada, mulberry shield scale, ivy shield scale, round spot leaf weevil, moth, pine and oak caterpillar, white velvet moth.

If it occurs, spray 2000 times of imidacloprid wettable particles or 1000 times of suspension to kill transparent and wide-winged wax cicadas and wide-winged wax cicadas. During the peak period of nymph oviposition, spray 95% Chesling emulsion 1000 times, or 20% Suke EC 1000 times to kill mulberry white shield scale; spray 3000 times of hyperosmotic phenoxyvir EC in the adult stage of leaf roll weevil Spray 3000 times of Kangfuduo solvent in the larval stage, 3000 times of hyperosmotic phenoxyvir EC in the larval stage of pine and oak caterpillars, and 1.2% nicotine 1000 times solution in the case of serious damage to the moth.

Harvest and processing of Forsythia suspensa

Due to different harvest time and processing methods, Forsythia suspensa is divided into three kinds: Forsythia suspensa, Fructus Forsythia and Forsythia suspensa.

1. Qingqiao: harvest immature cyan fruits from August to early September, boil them in boiling water for a while or steam for half an hour, take them out and dry them. It is better to be dry, non-cracked and greener.

2. Huangqiao: the ripe yellow fruit is harvested in early October and dried in the sun to remove impurities. It is commonly known as "Laoqiao". Those with dry body, large flap, thick shell and yellow color are better.

3. Forsythia suspense: sift out the seeds in the fruit shell and dry them in the sun.