Originally native to the mountainous areas of Qinling Mountains and Daba Mountain in western China, Hanzhong is the earliest place in China to cultivate peonies artificially. It is a deciduous subshrub. It likes coolness and hates heat, prefers dryness and fears humidity, can withstand low temperatures of -30°C, and can grow normally in areas with an annual average relative humidity of about 45%. Likes yin, but rarely tolerates yang. It requires loose, fertile, well-drained neutral soil or sandy soil, and avoid planting in heavy clay soil or low temperatures. Flowering period is April-May. The grafting method is often used for cultivation, because it belongs to the same genus as peony, and peony is often used as rootstock. 1. Soil quality: Peonies are suitable for loose, fertile and deep soil. The soil must have good drainage. General culture soil can be used for potted plants.
2. Soil: neutral or neutral slightly alkaline soil. 1． For planting, choose a sunny location without water accumulation, preferably a sunny slope, with fertile, well-drained sandy loam soil. Before planting, the soil should be plowed deeply. The planting pit should be appropriately large. The peony roots should be placed in the hole and stretched vertically, and the roots should not be punched. Planting should not be too deep, it is better to just bury the roots. There are generally fewer potted plants.
2． Sunlight with sufficient light and temperature is beneficial to its growth, but it cannot tolerate exposure to the hot sun in summer. If the temperature is above 25°C, the plant will become dormant. The optimum temperature for flowering is 17-20℃, but it must be treated at a low temperature of 1-10℃ for 2-3 months before flowering. The minimum ability to withstand a low temperature of - 30℃, but in the cold northern regions, appropriate cold protection measures must be taken in winter to avoid freezing damage. The hot and humid weather in the south is extremely unfavorable to the growth of peonies. Therefore, peonies cultivated in the south need to be given specific environmental conditions in order to enjoy the beautiful peonies.
3． Watering and Fertilizing Water twice before planting. Fill the plant with water once before winter to ensure it survives the winter safely. After the beginning of spring, water will be provided depending on the dryness and moisture of the soil, but do not overwater. Fertilizer is generally applied three times throughout the year, the first time is pre-flowering fertilizer, and quick-acting fertilizer is applied to promote the flowers to bloom well. The second time is post-flowering fertilizer, and the first topdressing is organic liquid fertilizer. The third time is autumn and winter fertilizer, mainly basal fertilizer, to promote growth in the following spring. In addition, pay attention to cultivating and weeding. If there are no weeds, shallow plowing can be done to loosen the soil.
4. After plastic pruning, pick flowers and branches promptly after the flowers have faded. Cut according to the natural growth of the tree and the desired tree shape. At the same time, apply callus antiseptic film on the pruning opening to protect the wound and prevent the invasion and infection of bacteria. If you want the plant to be low and have dense clusters of flowers, the short cut should be heavier to inhibit branch expansion and root tillering. Generally, it is appropriate to retain 5-6 branches per plant.
5． Flowering period control Potted peonies can bloom during the Spring Festival through winter flowering treatment. The method is to select strong peony varieties with full scale buds 60 days before the Spring Festival (such as Zhaofen, Luoyanghong, Shengdanlu, Gejinzi, Zhushalei, Da Zihuhong, Mokui, Wulong Pengsheng, etc.) are brought out with soil, with as little damage to the roots as possible, and then potted up after drying in a cool place for 12-3 days, and trimmed, leaving 10 branches with full terminal buds for each plant. Leave the top buds on and remove the remaining buds. When potting, the size of the pot should match the plant to achieve a satisfactory plant shape. After watering thoroughly, manage normally. 50-60 days before the Spring Festival, move it into a greenhouse at about 10℃ and spray water 2-3 times a day to keep the pot moist. When the scale buds swell, gradually heat up to 25-30°C, and the night temperature should not be lower than 15°C, so that flowers can be seen during the Spring Festival. Brown spot, red spot and rust; common pests include nematodes, grubs and cutworms. (1) Leaf spot: Also known as red spot, this disease is a fungal infection of the genus Polychaeta. The fungus mainly infects leaves but also new branches. The initial onset of the disease is usually around 15 days after flowering, and becomes increasingly severe as the temperature rises in mid-July. In the early stage, there are brown spots the size of grains on the back of the leaves, and the edges are slightly darker, forming irregular central ring-shaped dead spots that are thick on the outside, light in the middle, and blend into each other, causing the leaves to wither and fall. The petioles are damaged and produce a dark green downy layer; the stems and stems are infected and produce raised lesions; the pathogen overwinters in the stems, leaves and soil of the diseased plants.
Prevention and control methods: ① Around early November (the beginning of winter), sweep away the leaves in the ground and burn them intensively to eliminate the pathogenic bacteria; ②Spray 1:1:160 times before the onset of disease (in May) Bordeaux mixture should be sprayed once every 10 to 15 days until the end of July; ③ In the early stage of the disease, spray 500-800 times thiophanate methyl and carbendazim once every 7-10 days, 3-4 times in a row.
(2) Purple feather disease: It is a fungal disease. Spread by soil. The disease occurs at the root neck and roots, with the root neck being more common. There are purple or white cotton-like mycelium in the injured area, which is yellow-brown at first and then dark-brown, commonly known as black pimple head. In mild cases, flaky patches will form, no new roots will grow, branches will be thin, leaves will turn yellow, and buds will become shriveled; in severe cases, the entire root neck and system will rot, and the plant will die. This disease mostly occurs during the hot and rainy season from June to August. After September, as the temperature drops and the rain decreases, the disease spots stop spreading.
Prevention and control methods: ① Select high-dry plots with good drainage for planting; ② Timely cultivating during the rainy season to reduce soil moisture; ③ Rotate crops every 4-5 years; ④ Breed disease-resistant varieties; ⑤ Use 500 when planting separately Apply pentachloronitrobenzene liquid to the affected area before planting, or water the roots with 1000 times of 5% dacenium; ⑥ Disinfect the area around the affected plant with lime or sulfur.
(3) Sclerotinia sclerotiorum. Also known as stem rot. The pathogen is Sclerotinia sclerotiorum. When the disease occurs, water-soaked spots appear on the stems near the ground, gradually expand and rot, and white cotton-like material appears. Leaves and flower buds may also be infected.
Prevention and control methods: Choose high-dry plots with good drainage for planting; dig out diseased plants promptly and disinfect the soil if found; rotate crops every 4-5 years.
Anthracnose and rust are also common. Anthracnose causes round or irregular light brown sunken lesions on the leaves, with purple-brown edges after expansion; rust causes yellow spore piles on the back of the leaves, causing the leaves to turn green, and in the later stages, columnar hairs appear on the diseased leaves. The prevention and treatment methods are the same as those for leaf spot.
Propagation and cultivation are commonly done by division and grafting, but also by sowing and cutting. The suitable period for transplantation is from late September to early October, and cannot be too early or too late. Like
fertilizer, fertilization should be applied at least three times a year, namely "flower fertilizer", "bud fertilizer" and "winter fertilizer". Pruning should be carried out after 2-3 years of cultivation. For varieties with strong growth potential and strong branching ability, only thin and weak branches need to be cut off and all strong branches should be retained. The sprouting tillers at the base should be removed in time to maintain a beautiful plant shape. Removing buds is also an extremely important task. In order to make the plant bloom abundantly and brightly and keep the plant strong, the number of blooms should be controlled according to the age of the tree. In the early stage of budding, select a certain number of fully developed flower buds and remove excess buds and weak buds as soon as possible. Generally, plants that are 5-6 years old retain 3-5 flower buds. For newly planted plants, all flower buds should be removed in the second spring to prevent them from blooming to concentrate nutrients and promote plant development.
Peony is a deep-rooted deciduous shrub flower that likes sunlight and is cold-tolerant. It prefers a cool environment but avoids hot and muggy temperatures. It is suitable for growing in loose, fertile and well-drained sandy soil. Therefore, generally, the potting soil for cultivating peonies should be a mixture of sand and cake fertilizer, or a culture soil with a mixture of fully decomposed manure, garden soil, and coarse sand in a ratio of 1:1:1. If there is too much water in the cultivation soil, the fleshy roots will easily rot. Therefore, when encountering continuous rainy weather, water must be drained in time and water must not be allowed to accumulate at the roots. Peonies are not resistant to high temperatures, so cooling measures must be taken in time when the weather is hot in summer. It is best to build a pergola to provide shade. Cover it with straw curtains or reeds before noon and remove it in the evening. If this measure is done in time, it can prevent the leaves from falling off. If they are allowed to be exposed to heat and fall off, it will seriously affect future flowering. Peonies have long roots and large plants, so they are suitable for ground planting. If you want to plant them in pots, you should choose a large, well-permeable tile pot with a pot depth of more than 30 cm. It is best to use a tile cylinder with a depth of 60-70 cm. Peonies can be propagated by sowing, dividing or grafting.