Grapes begin to germinate in late March, spread their leaves in early April and mature in autumn. To make potted grapes bear fruit, we should pay attention to the following points. 1. Variety selection: It is best to choose a cultivated variety with medium plant growth and short internodes for potted plants, and it should have the characteristics of beauty and good taste. Its varieties are Kyoho, Beijing Red, Golden Queen, Rose Fragrant, Italy and so on.
2. Location: Grapes like plenty of light. Potted grapes should be planted on the balcony facing south, so that they can receive enough light to promote vigorous growth, short internodes, thick leaves and full fruits. On the contrary, internodes become longer, leaves become thinner, and new shoots become thinner, making it difficult to blossom and bear fruit.
3. Potted soil: Grapes like loose and fertile neutral or slightly alkaline humus soil. The culture soil can be a mixture of garden soil 1, humus soil 1 and rice bran ash 0.5. Because the root system of grapes is relatively developed, the pots used are generally more than 25 cm in diameter, or small cylinders are used. Turn over the pot to change the soil 1 time a year.
4. Fertilization: Rational fertilization is the key to the vigorous growth and fruitful results of grapes. In the process of growth, not only enough nitrogen fertilizer is needed to promote the growth of branches and leaves, but also phosphorus fertilizer and potassium fertilizer must be provided to meet the demand of flowering and fruiting. Fertilization is based on the principle of thin fertilizer and diligent application. In winter after fruit bearing, base fertilizer combined with nitrogen and phosphorus should be applied in time, and nitrogen-based topdressing 1 time should be applied every 10 day when the stems and leaves grow, or 20% decomposed cake fertilizer or human excrement and urine should be applied. During the young fruit period from June to July and the fruit coloring period in early August, apply 1 ~ 2 times of thin fertilizer, which is mainly composed of phosphorus and potassium fertilizer, to promote lush green leaves and fruitful fruits. Before fertilization, watering should be stopped, and the pot soil is slightly dry, which is beneficial to the absorption of fertilizer.
5. Watering: The balcony is windy and easy to dry, with large leaf area, large evaporation and large water demand. So, pay attention to watering. Especially in hot summer, water enough in the morning, and replenish water when the soil is dry at night 1 time. If the soil in the basin is too dry, it will easily lead to falling flowers and fruits. Grapes avoid water accumulation, often raining or watering too much, high environmental humidity or water accumulation in the basin, which is easy to cause root rot and fruit drop. After defoliation in winter, it enters a dormant period, and the basin soil remains slightly dry.
6. Pruning: 1 Pruning should be carried out before the winter solstice germination. In addition to cutting off dead branches, diseased branches and weak branches, the fruiting branches should also be cut short, leaving only 1 ~ 2 buds for the winter. Buds and tendrils should also be trimmed properly during the growing period. Only one main vine is left in each pot, and only about 10 fruiting branches are left on the main vine, and each fruiting branch only needs one ear and six leaves. Secondary buds growing in leaf axils need to be removed in time to reduce nutrient consumption.
7. Tea rack: Generally, 3 ~ 4 bamboo poles are inserted in the pot, and some small bamboo poles are added at the bottom and middle to make the rack stable, and the main vines and fruiting branches are placed on the shelf.
8. Cutting propagation: Potted grapes, like ground planting, adopt cutting propagation to cultivate strong seedlings. When the grape leaves fall, select the whole branch of the year with short internodes and three bud eyes, and cut it to about 10 cm, with 3 ~ 4 leaf buds. The lower cut should be close to the bud eyes, and the upper cut should be 2 ~ 3 cm above the bud eyes. Buried in wet sand in winter. From mid-March to early April of the following spring, cuttings should be planted in seedbeds or directly in pots, with 3-4 cuttings in each pot. After watering, the pot soil should not be too wet, and it can take root in 20-30 days. When the new shoots grow to 5-6 leaves, all the secondary branches in the tender shoots and leaf axils are removed, and a bamboo pole with a height exceeding 1 m is inserted next to the roots as a pillar. When the secondary buds germinated for the second time grow to 6 leaves, bud-point again, and bud-point 2-3 times throughout the year to cultivate seedlings with plant height of about 1, stout main stems and full winter buds. From March to early April in spring, seedlings can be put into pots.