Yellow roses are characterized by their love for cold and fear of heat, their love for yang and their aversion to yin, their tolerance to fertilizer and their fear of barrenness, and their love for growing in fertile soil. It can grow vigorously all over the north of the Yangtze River, but there are many diseases and pests in Lingnan in summer, which is a great threat to the growth of roses. In the past, many flower farmers thought it needed "summer sleep" when they saw the branches and leaves turning yellow, so they cut off the whole branches, leaving only the basic trunk, and then urged it to germinate when it was cool in autumn. So no matter the size of the flower bed, roses are rare. In fact, in the "dog days" from June to September, its plants did not sleep late, and its cells were tenaciously alive. According to the field investigation, roses planted per mu usually bloom about 35,000 ~ 42,000 a year, of which 15% ~ 20% is in summer. Although the flowers in summer are smaller, they are not impossible to bloom. It is easy for producers to master the cultivation and management of roses in spring, autumn and winter, but attention should be paid to planting roses in summer. In addition to selecting varieties with strong heat resistance, moisture resistance and disease resistance, corresponding measures must be taken to make plants "live well, drink enough and eat enough" in summer.
First of all, pay attention to "grafting". Wild rose (called "Seven Sisters" in Guangdong) should be used as rootstock, and superior varieties should be used as scions. Cutting propagation is not allowed, so that after grafting, the root group is developed, the propagation ability is strong, and the flower picking period is prolonged. Secondly, it is necessary to implement "summer heat dissipation", intertillage the soil, and sprinkle water directly on the branches and leaves at noon to reduce the ground temperature. Third, it helps to "keep fit". Take the initiative to attack diseases and insect pests such as black spot, powdery mildew, thrips and red spider. A variety of broad-spectrum fungal pesticides should be applied in turn every seven or eight days for diseases, and pesticides with comprehensive effects of internal absorption and contact killing should be selected for pests. Often topdressing and applying more organic fertilizer. "Black and white ash" mixed with lime and plant ash is often sprayed to enhance the stress resistance of plants. The fourth is timely "pruning and cosmetic surgery". Don't wait for the petals to fall, cut them before they bloom, so as not to consume nutrients. The cutting place should be aimed at the upper part of the leaf axils, because there is a bud hidden between each leaf axils. If preserved, new branches and flowers will soon grow. As for the trimmed part, it is best to cut it in the middle of the main branch at the opposite position of the leaf axils. If you cut it too low or too high, it will not be ideal for the next flowering.
Roses can be propagated by sowing, cutting, branching and grafting, but generally branching and cutting are the main methods.
Branch method: it can be carried out in spring or autumn. Choose a rose plant that grows vigorously and dig it up by roots. According to the growth trend of roots, plants are divided into several plants from roots and planted separately. Generally, rooting and propagation are carried out every 3-4 years.
Cutting method: it can be done in spring and autumn. Both the hard branches and the tender branches of roses can be used as cuttings. Hardwood cutting: Generally, before the plants germinate in February and March, 2-year-old robust branches are selected, cut into 15 cm sections as cuttings, coated with soil at the lower end, and inserted in the seedbed. Generally, cuttings can take root about 1 month, and then transplant and maintain in time. Cutting can also be carried out when pruning plants in winter from June to February in 5438.
Grafting method: generally, Rosa davurica and Rosa davurica are used as rootstocks, and grafting method or cutting method is adopted in early spring and March.
Seed propagation: A single rose can propagate through seeds. When the seeds are ripe in June+10/October, 5438, harvest and sow them in time; Or hide the seeds in the sand until the next spring. Double rose bears no fruit, so it can't be propagated with seeds.