Cultivation and Management of Populus tomentosa

Propagation method: sowing and cutting propagation.

Seeds usually mature in October. The seeds of Populus tomentosa have the characteristics of germination every other year after vernalization, so the seeds are collected and buried in wetter sand, and then sowed in sandy soil in the following spring. The seeds are dry after harvest, the seeds are protruded after the fruit shell is cracked, and the seeds are removed from dry storage, sown in winter or spring. After sowing, the covering soil must not be too thick, and it should be suppressed properly after covering the soil, so that the seeds can combine closely with the soil, help the seeds absorb water and promote germination, and keep the seedling bed moist. The bed was changed and transplanted in March next spring, and the row spacing was enlarged. The growth in the seedling stage is very slow, and it is still necessary to stay in bed for 3-4 years after transplantation, and go out of the nursery according to the required specifications for greening.

Cuttage propagation can be carried out at any time, but the survival rate of cuttings with young branches growing in the same year is high in summer. Use sandy soil as cutting substrate, take semi-mature branches as cuttings, 10-12 cm long, with heel, leave leaves about 10, cut the base of cuttings flat, oblique into the bed, in order to facilitate air and light, insert into the soil 1 / 2-2 / 3, after planting solid, fully watered, the bed to build a shed for shade, prevent direct sunlight, often spray water to keep moist. In that year, the root system of cuttings is underdeveloped and vulnerable to freezing damage, so weeds or plastic film can be used to protect them in winter. Leave the bed for one year and then plant it separately.

Transplanting and colonization of seedlings are mostly carried out in winter and spring, and they all need to bring dormant soil. If it is planted as a hedge, the density should be increased to take shape as soon as possible. If you need to form large materials, plastic training should be carried out. Populus tomentosa is very resistant to shaping and pruning, if it is not pruned, it has few branches and small crown diameter, but it should pay attention to the timing of pruning. After planting, it is necessary to pay attention to pruning (commonly known as topping), especially for buds from the base, branches should be cut off half a year later, especially tall branches can be cut more. It should be cut two or three times a year. Two years later, the branches were plump and the height was in harmony with the crown diameter. Pruning should be carried out before germination and after the growth stops completely in autumn, pruning between summer and autumn is easy to stimulate secondary growth, and it is a measure to accelerate shaping in the south where the temperature is higher in winter, but in the north, such as underdeveloped autumn shoots, it is easy to suffer frost damage in winter. The planting site should be a shelter when planting in the open field north of the Yellow River, otherwise it is also vulnerable in winter. Water properly in the dry season to avoid falling leaves at the base of the drought. The common diseases of Populus tomentosa are brown spot, leaf spot and defoliation, which usually occur in the season with high temperature and humidity. The prevention and control should be started in the middle of May. Bordeaux solution or topazine and carbendazim should be sprayed on the new branches and leaves and sprayed once in June and early July respectively. Aphids often occur in late spring and midsummer, and can be sprayed with dimethoate 1500 times. If urea is added to the above solution, foliar fertilization can be carried out at the same time. Attention should be paid to fertilizing the roots of boxwood in spring and summer. Urea can be sprinkled on the roots before and after rain, or chemical fertilizer can be used.