You can refer to some of He Laoshi's posts! ~ management of elm bonsai in winter, some bonsai need to be strengthened, so how to manage elm bonsai in greenhouse in winter? Ventilation can reduce temperature and humidity, prevent pests and diseases, and supplement indoor effective gas components. When the temperature is too high, some evergreen piles are still growing, which are easy to grow, with thin branches and poor stress resistance. Deciduous piles are easy to break the dormancy period, which leads to the weakness of branches when going out for exercise in spring, which is not conducive to future growth and is easy to age. Generally, it is better to ventilate at noon on sunny days. The size of the vent should be properly ventilated according to the growth habit and temperature requirements of the pile site to reduce the temperature and humidity. Outdoor weather is cold, the ventilation vents should be small and the ventilation time should be short, whereas the ventilation vents should be large and the time should be long. Glass materials should be used for smooth greenhouse surfaces. This kind of greenhouse has good performance and high transparency, but the disadvantage is that it blocks the injection of ultraviolet rays. Ultraviolet rays can hinder the growth of pile landscape white, limit its growth height, and play a role in sterilization and disinfection. If there is not enough ultraviolet radiation, the growing evergreen branches in the pile landscape will easily grow white, soften and destroy their shapes. Therefore, it is necessary to partition, slice, open the glass window, and gradually get direct sunlight to make its branches full and strong. In some areas, agricultural film is used to prevent cold, and the illumination time depends on the regional temperature. Open the film properly for lighting and ventilation in sunny days and high temperatures. Generally, it lasts for 2 to 3 hours a day, which can prevent the occurrence of diseases for deciduous piles. Sprinkling water should be carried out at noon. At this time, the soil temperature and water temperature are close, which is beneficial to root absorption. In addition, a large amount of ineffective water can be evaporated, which can reduce the difficulty of root respiration caused by excessive soil moisture and prevent mildew. Conducive to water circulation in the body and increase its resistance. For the dormant deciduous pile landscape, "seeing dry and seeing wet" is perfect. Fertilization for the growing pile landscape, in this season, phosphorus and potassium fertilizer should be given priority to, supplemented by nitrogen fertilizer, and the fertilization time should be in the sunny afternoon. The piles of deciduous trees are dormant, so fertilization should be prohibited. The production, maintenance and management of bad landscape of Ulmus pumila (1) can be used for sowing and seedling raising. In June 10 ~ 1 1 when the seeds are mature, they are harvested in time, spread out and dried, impurities are removed, and bagged and stored in dry storage. Sow in March of the following spring. Sow almost the whole seedbed on a calm sunny day, cover it with fine soil and then cover it with straw. /kloc-germinate around 0/month, uncover the grass in time, and properly sparse the seedlings. During the growth of seedlings, water and fertilizer management should be done well, and the annual seedlings can be as high as 30 ~ 40 cm. It should be cultivated in bed for several years, trimmed and shaped, and then processed in a pot. You can also dig an old elm stump at the water's edge in Shan Ye, and choose the one with thick exposed roots, strong twists and turns, leafy branches and ancient posture. After embryo culture, when the root system develops and new branches and leaves flourish, they are put into basin-force oral modeling. (2) Selection of upper pot ① Pot: The elm tree is simple in shape and its leaves are oily green, so it is advisable to use purple sand pottery pot or glazed pottery pot. The shape of pots depends on the shape of trees, and rectangular and oval pots are the most common. The color of the basin is simple and elegant. (2) Soil: loose and fertile mature pastoral soil or humus soil is suitable for potted plants, with good ventilation and water permeability, which is conducive to the development and growth of roots. (3) Planting: Planting potted seeds before bud germination in February-March in spring. When planting, properly trim the roots, cut short the long roots, cultivate fertile soil, and don't bend the roots. The planting of elm bonsai with attached stones includes the following steps: firstly, selecting loose stones with crevices, pruning the roots, putting them in crevices, and fixing them with brown thread bolts to avoid damaging the roots, paving moss, coating wet river mud on the stones after rooting, and then wrapping them with moss, then planting the roots and attached stones in pot soil, and carefully maintaining them for 2-3 years until the roots embedded in crevices fully grow and fill the crevices. (3) Modeling The processing and modeling of elm can be combined with pruning and climbing, and climbing can be made of brown silk or metal wire. Because the branches of elm grow rapidly, they should be removed in time after climbing and forming, so as to avoid wire trapping and affecting the appearance. In the growing period, new branches can be cut off to promote the growth of branches and distort the shape of branches. Elm has strong plasticity and can be processed into various forms. Common ones are straight dry type, inclined dry type, horizontal dry type, cliff type and stone-attached type. Branches and leaves can be cut into pieces or trimmed into natural crowns. In particular, the V is a stone-attached elm bonsai, with a certain exaggeration in shape. Trees can be placed on rocks, mainly trees, supplemented by stones, and are not restricted by "Zhang Shan Shu Chi". Maintenance and management (1) Watered elms like to be wet, and the basin soil should be wet, but not waterlogged. During the high temperature period in summer, water should be poured once every morning and evening; You can reduce watering in autumn, and if the flowerpot is buried in the soil in winter, you don't need to water it. (2) During the growth period from April to 10 (except rainy season), 1 pancake fertilizer and water can be applied every half month to maintain the normal growth of nutrients. Apply 1 times cake fertilizer or manure as base fertilizer in winter. (3) After pruning, the branches and leaves of elm grow rapidly. When the new branches grow to 5-6 cm, leave 2-3 leaves and cut off the rest. In order to maintain the modeling style, pruning or bud removal is often carried out to control its virtual length so as not to disturb the tree shape. (4) The landscape of elm piles grows slowly, and it can be turned once every 2-3 years, preferably before germination in spring. When turning over the pot, some old roots can be cut off and 1/2 old soil can be replaced to cultivate fertile and loose culture soil, promote root growth and flourish branches and leaves. (5) Pests and diseases control The common pests of Ulmus pumila include Ulmus pumila, scale insects, longicorn beetles, moths, etc. It can be controlled by spraying 80% dichlorvos 1500 times. Long-horned beetles eat tree trunks, and they can block the wormhole with a mixture of stone and sulfur. During the maintenance period, keep the environment clean, and Chen Fang is located in a well-ventilated and light-transmissive place.