Several environmental conditions that should be paid attention to in growing American ginseng

American ginseng is native to southeastern Canada and northeastern United States. It grows in broad-leaved forests in the low mountain area of 100m to 500m above sea level. There is little change in cold and summer in this area. The monthly rainfall distribution is relatively uniform and has the characteristics of temperate marine climate. American ginseng has been wild for a long time in this environment, forming the growth characteristics of fear of sunshine, shade and dampness, fear of cold, temperature and coolness. Therefore, in the process of planting American ginseng, we should pay attention to the influence of environmental conditions on it and regulate it reasonably.

I. temperature

After the morphological mature seed split, the seed embryo of Panax quinquefolium can complete physiological maturation after 3.5-4 months at the temperature of about 5 ℃, while the rhizome bud needs more than 2 months at the temperature of about 5 ℃ to break dormancy and have the physiological conditions for seedling emergence. Generally, American ginseng begins to emerge when the soil temperature is more than 10 ℃, and it is the most suitable for seedling growth when the soil temperature is 15-18 ℃, and the average temperature at flowering stage is above 20 ℃. Panax quinquefolium was not tolerant to severe cold. The annual rhizome was frozen at-12 ℃ and the main root at-17 ℃. The alternating change of high and low temperature can freeze the ginseng root more than continuous low temperature. therefore, the border surface of American ginseng in the north must be covered with cold protection in winter.

Second, lighting

Because American ginseng has been wild under the broad-leaved forest for a long time, the light in the forest is insufficient and it is relatively damp, which makes American ginseng adapt to shade and humidity. It is particularly sensitive to light, most afraid of direct light, and likes scattered light and oblique light, belonging to shade plants. Generally, large shade is needed in infancy (one or two years old), and proper increase of light is needed in adulthood (three or four years old). The light intensity can be increased appropriately in the growing season with lower temperatures (such as spring and autumn) and in areas with lower temperatures (such as the north or high mountain areas). In the growing season with higher temperatures (such as summer) and areas with higher temperatures (such as the south or low mountainous areas), the shade should be increased appropriately. Illuminance is generally controlled between 10% and 30%, or even less than 10%. In adulthood and in seasons and areas with lower temperatures, illuminance can be controlled between 20 and 30 per cent. The suitable illuminance of cultivated American ginseng is not only affected by the growth age and different growth and development periods of ginseng seedlings, but also greatly affected by climate change. Therefore, the light intensity should be adjusted flexibly according to the specific situation.

Third, moisture

American ginseng is sensitive to water, the requirement is also very strict, lack of water, American ginseng growth is poor, low yield, ginseng root epidermis is easy to turn yellow or burn beard, serious will make the whole plant wither. Because the root system of Panax quinquefolium is underdeveloped, the whisker root is mostly distributed in the tillage layer, and the root hair is less, so it is not tolerant to drought. This requires that the sandy soil with poor water retention should be replenished in time in the dry season, but the water should not be saturated. If there is too much water, it is easy to cause root diseases and serious death will occur. Therefore, in the process of cultivation and management of American ginseng, water management is very important, which will affect the yield and quality of American ginseng.

American ginseng has different requirements for water in different growth stages. generally, from seedling stage to aboveground growth stage, sufficient water supply is needed due to the increase of growth, and this stage of growth and development of American ginseng is also in the period of spring drought. so it is necessary to water frequently to keep the soil on the border moist. July and August are in the rainy season and generally do not need watering. In addition, during the overwintering period, if the soil water content is too large, it will cause ginseng root and bud freezing injury, which needs to be prevented.

IV. Soil and fertilizer

American ginseng is suitable to be planted in slightly acidic soil with high humus content, fertile soil, soft soil, water conservation, fertilizer conservation, air permeability, good aggregate structure, no consolidation and pH 5.5-6.5. Sandy soil, saline-alkali land and poor drainage are not conducive to the growth of American ginseng and susceptible to disease.

American ginseng has a small plant, slow growth and limited growth, so the requirement of fertilizer is moderate. If the soil is fertile and loose, there is no need to fertilize American ginseng. If American ginseng is cultivated in farmland soil, the soil should be improved as necessary. Those with low content of organic matter should apply more organic fertilizer as base fertilizer, and those with sticky soil can be mixed with sand. During the growth period of Panax quinquefolium, phosphorus and potassium fertilizer and a small amount of nitrogen fertilizer should be applied properly. Remember one thing: nitrogen fertilizer should not be applied more, otherwise it will cause the plant to grow and reduce the resistance.