Varieties used for potted jujube trees should have the characteristics of early fruiting, great fruit, beautiful branches and compact tree shape. The excellent ornamental varieties of jujube suitable for potted plants mainly include: ① Longxu jujube. The tree is weak, and the developing branches, fruiting base branches and falling fruit branches are all bent and twisted, and the branches are strange, such as dragon claws, so it is also called dragon claw jujube. The fruit surface is often uneven and twisted, and the ornamental effect is good. ② teapot jujube. The fruit shape resembles Yixing teapot, hence the name. ③ Gourd dates. There are ripple marks in the middle and upper part of the fruit, which are gourd-shaped or millstone-shaped, and the fruit shape is beautiful, so it is also called ripple mark jujube and millstone jujube. ④ Persimmon dates. Its main feature is that the sepals at the base of the fruit persist, initially green, thickening and fleshy with the development and maturity of the fruit, and finally dark red, similar to the pedicel of persimmon. ⑤ The fetus is red. This tree has medium potential and high yield. The fruit is conical and pink. After fertilization, the disk and ovary are purple, so it is called fetal red, and the twigs and veins are purple, which has special ornamental value. ⑥ Winter jujube. Also known as Apple Jujube, the tree shape is weak, the annual branches are purplish red, the leaves are degenerated, the leaves are oblong, the fruit is round, and it is reddish to the sun before maturity, and its appearance is beautiful. The fruit quality is good. In addition, other varieties with their own characteristics can be selected, such as Yangjiao jujube, Lizao jujube and Yimeng seedless black jujube.
2 Upper basin
2. 1 Upper Basin Stage
Jujube trees are mostly planted in spring, and the survival rate is high before germination in spring. It is suitable for planting in North China in the middle and late April. If the wintering conditions are good in winter, you can also go to the basin after falling leaves in autumn. In this way, early spring germination can shorten the slow seedling stage and promote the early growth and development.
2.2 Canned containers
In order to facilitate maintenance, a plain burning pot (earth pot) suitable for the size of the tree is generally selected to make it quickly set and easy to bear fruit. After molding, it can be replaced in glaze basin, purple sand basin, porcelain basin or wooden basin (barrel) to increase its ornamental value.
2.3 Pot soil preparation
Potted jujube trees do not have high requirements for pot soil, but because of their growth and development in limited soil, pot soil is required to be loose and fertile, with good air permeability and strong water and fertilizer retention capacity. 4 parts of garden soil, 2 parts of humus soil, 2 parts of manure and 2 parts of sandy soil can be used as basin soil after being fully mixed according to the volume ratio.
2.4 Basin method
Check whether the water hole at the bottom of the basin is unobstructed, cover the hole with the convex surface of the broken basin, spread the slag about 2cm later, and add a small amount of culture soil. Prune seedlings before planting, cut the wound flat, cut off the injured roots and leave more fibrous roots; When planting, make the roots stretch and closely connect with the soil. For roots with large or thick taproots, you can gently insert bamboo sticks or wooden sticks into the soil around the roots and pat the waist with your hands to avoid a big gap in the rhizosphere. The planting depth should be the same as the original soil mark (root neck) of jujube seedlings. If it is a grafted seedling, the interface should be exposed to the soil surface, and the pot soil should be 80% full, leaving about 20% of the nozzle for irrigation. Water the basin in time after putting it on, and then put it in the leeward and sunny place to keep the soil moist.
3 plastic pruning
Jujube is a light-loving tree species, and the pruning reaction is slow. It is necessary to keep the canopy ventilated and transparent in order to make it grow well. You can choose curved trunk, natural shape with three main branches and Youlong shape. Pruning adopts a combination of winter pruning and summer pruning. The main purpose of winter pruning is to cultivate a tree. After cutting off the jujube head of the main branch that needs to be extended, cut off the first secondary branch under the cut to promote the germination of the main bud and form new extended branches. At the same time, the symbiotic branches, cross branches, overlapping branches and pest branches on the tree body are refined. For the branches with the result of use, the biennial part is generally cut off, and the cut secondary branches are cut off. Summer pruning is mainly to control excessive branches by wiping buds, thinning branches and coring, and we should always pay attention to erasing excess jujube heads. Potted jujube trees take shape quickly, and generally they can finish the task of shaping and pruning in the same year. Therefore, the sprouted new jujube heads are all erased from the base except for regeneration, so as to save nutrient consumption, maintain ventilation and light transmission in the crown, and concentrate nutrition to promote the development of secondary branches, jujube hanging and flowers and fruits.
4 Soil, fertilizer and water management
Potted jujube trees need more careful water and fertilizer management than cultivated jujube trees in the open field because of limited pot soil. Early spring germination should be combined with basal fertilizer watering 1 time. The germination, branch growth, flower bud differentiation, flowering and fruit setting of jujube trees are almost simultaneous, which has great demand for nutrition. Therefore, after combined application of organic fertilizer before and after flowering, available nitrogen fertilizer should be applied appropriately, and watering at this stage should follow the principle of small amount and multiple times. In the second rapid growth period (expansion period) of fruit, topdressing the quick-acting fertilizer mainly containing phosphorus and potassium, and applying base fertilizer in autumn can enhance the tree vigor. In addition, weed seeds or root segments are often found in the soil during the 1 year of potted plants. When they germinate, they should be pulled out immediately. Because of frequent watering, the basin soil is easy to harden, so it should be cultivated 1 time every spring to loosen the basin surface soil appropriately. You can also raise a small amount of earthworms in the basin, which not only loosens the soil, but also enriches the soil.
5 Overwintering management
Potted jujube trees can overwinter indoors or outdoors. If you spend the winter indoors, you should choose a vacant room without heating equipment. Generally, the basin will be moved indoors in the middle and late February of 12, and watered before entering the house. To keep the humidity, you can put the flowerpot into a plastic bag, tie the mouth of the bag on the trunk, or wrap the mouth of the flowerpot tightly with plastic film. Overwintering outdoors means watering the flowerpot and burying it underground, so that the mouth of the flowerpot is flush with the ground or slightly lower than the ground. You can also concentrate well watered potted trees in the corner of the courtyard, and block a wall about 10cm higher than the flowerpot with bricks or boards around it. Gaps between walls and flowerpots and between flowerpots are filled and covered with weeds, leaves and sawdust.