Hydrangea Cultivation and Management Methods and Pest and Disease Control Techniques

Hydrangea is a very beautiful plant and a preferred choice of home-grown plant variety for many people. Below, the editor will talk with you about hydrangea propagation, flower forcing treatment, and pest and disease control cultivation techniques.

1. Propagation Techniques

Hydrangeas are commonly propagated by cuttings, division, layering, and grafting, with cuttings being the main method in production. Under protected conditions, cuttings can be taken at any time, but to make them bloom in early spring, mass cutting propagation can be carried out in August to September. When taking cuttings, select vigorous young shoots from young mother trees as cuttings. The cuttings should be about 15 cm long, with a node at the base. Remove the lower leaves and dip them in a rooting agent solution mixed with mud. The suitable temperature for cuttings is 13°C to 18°C. After inserting, shade is needed and moisture should be maintained regularly. Roots develop in about 20 to 30 days, and after survival, they can be transplanted in the second year. In production, substrate-based seedling cultivation is usually adopted. The substrate generally uses peat : perlite = 5:1 ratio, and seedlings are grown in 10 cm nutrient pots.

For home use, division propagation can be used, which is suitable before budding in early spring. Separate the rooted branches from the mother plant and pot them directly. Do not water too much. Keep them in semi-shade, and after new buds sprout, switch to normal care. Layering propagation can be done when buds begin to swell. Growth occurs after 30 days, and the following spring, cut from the mother plant, transplant with soil, and they can bloom that year. Generally, air layering is done in March to April in spring, roots form in June to July, and they can be cut off and planted separately that year. Grafting propagation can use Viburnum macrocephalum seedlings as rootstock. Cleft grafting in spring makes survival easy. Division and grafting are generally rarely used in large-scale production. Transplanting is best done after leaf drop or before budding, taking care to avoid damaging the root system. The main branches easily produce water sprouts, so proper pruning is needed after flowering to shape the tree.

2. Dwarfing Treatment

Select dwarf mother material for cutting propagation of seedlings, combined with pruning. Use chlormequat chloride spray treatment at a concentration of 2000 ppm, that is, 1 kg of water should be added with about 2.04 g of 98% chlormequat chloride original powder. The spraying time of chlormequat chloride is generally 20 days after repotting, with an interval of 15 to 20 days for another spray. Two to three consecutive sprays can achieve the goal of promoting shortened internodes and fuller potted plants.

3. Cultivation and Management

The suitable growth temperature for hydrangea is 18°C to 28°C, and the winter temperature should not be lower than 5°C. Flower bud differentiation requires 6 to 8 weeks at 5°C to 7°C. A temperature of 20°C can promote flowering. After flowers appear, maintaining 16°C can extend the viewing period. However, high temperatures cause flowers to fade quickly. Hydrangea is a short-day plant. With more than 10 hours of darkness treatment per day, flower buds can form in about 45 to 50 days. Potted hydrangeas commonly use 15 to 25 cm pots. After spring budding, potted plants should be watered thoroughly to ensure leaves do not wilt. During the flowering period from June to July, fertilizer and water should be sufficient, with fertilization once every half month. Normally, cultivation should avoid direct sunlight, with 60% to 70% shading being ideal. When light is too strong in midsummer, proper shading can extend the flowering period. After flowering, remove the flower stems to encourage new branches.

For hydrangea cultivation, loose, fertile, and well-drained sandy loam is best. However, flower color is affected by soil pH. Acidic soil produces blue flowers, and alkaline soil produces red flowers. To deepen the blue color, aluminum sulfate can be applied during the bud formation stage. To maintain pink, lime can be applied to the soil. The potting soil should be kept moist, but watering should not be excessive. Especially in the rainy season, drainage should be noted to prevent root rot caused by waterlogging. In winter, indoor potted plants are better kept slightly dry. If too moist, leaves are prone to rot. Repot once every spring. Prune properly to maintain a beautiful plant shape.

4. Flower Forcing Treatment

Place potted hydrangeas that have reached the required vegetative growth stage in a dark cold storage at 5°C to 7°C for 45 days starting in mid-October in winter for low-temperature forcing treatment. After the period ends, the leaves will turn yellow or rot. Then transplant them to a greenhouse for care, and they can bloom relatively uniformly during the Spring Festival.

5. Pests and Diseases and Control

The main diseases of hydrangea are wilt disease, powdery mildew, and leaf spot disease, which can be controlled by spraying 600 times dilution of 65% zineb wettable powder. Pests include aphids, red spiders, and plant bugs, which can be killed by spraying 1500 times dilution of 40% omethoate emulsifiable concentrate.

The above are the key points of hydrangea cultivation and management. Friends who want to grow hydrangeas can first follow Huinong Network to learn related cultivation techniques.

Hydrangea Cultivation and Pest and Disease Control

Hydrangea Cultivation and Management and Cultivation Precautions

The correct name of hydrangea is Hoya, also known as hydrangea, ziyang flower, qibianhua, foreign hydrangea, and powder ball flower. It is native to the Sichuan area of China and Japan. It is a deciduous shrub of the genus Hydrangea in the family Hydrangeaceae under the order Cornales. Its flowers are almost entirely sterile flowers; the so-called "flowers" are only sepals. China cultivated hydrangeas relatively early, and hydrangeas were planted in Jiangnan gardens built during the Ming and Qing dynasties. Parks built in the early 20th century also could not do without hydrangea plantings. Modern parks and scenic areas plant them in large patches to form landscapes. Artificially bred hydrangeas have large flowers and bright colors, including blue, white, purple-red, pink, and peach red, and are a common ornamental flowering shrub.

Growth Habits of Hydrangea

We must first understand the growth habits of hydrangea in order to specifically master the cultivation methods of hydrangea. Hydrangea is native to the Yangtze River Basin of China and likes warm, humid, and semi-shaded environments. It fears both drought and waterlogging, and is not cold-tolerant. In cold regions, the aboveground part dies in winter and only sprouts new shoots again the following spring. Hydrangea likes fertile, moist, well-drained light loam and has strong adaptability. The acidity and alkalinity of the soil have a relatively large impact on the flower color of hydrangea. In acidic soil, it is mostly blue, and in alkaline soil, it is mostly red.

Propagation Methods of Hydrangea

Commonly propagated by cuttings, division, layering, and grafting, mainly by cuttings. During the plum rain period, select vigorous young shoots from young mother trees as cuttings. The base of the cuttings should have a node and be dipped in mud. They should be about 20 cm long, and the lower leaves should be removed. The suitable temperature for cuttings is 13 to 18°C. After insertion, shade is needed and moisture should be maintained regularly. Roots develop in about 15 days to 1 month, and after survival, they can be transplanted in the second year. Division propagation is suitable before budding in early spring. Separate the rooted branches from the mother plant and pot them directly. Do not water too much. Keep them in semi-shade, and after new buds sprout, switch to normal care. Layering propagation can be done when buds begin to swell. Growth occurs after 30 days, and the following spring, cut from the mother plant, transplant with soil, and they can bloom that year. Generally, air layering is done in March to April in spring, roots form in June to July, and they can be cut off and planted separately that year. Grafting propagation uses Viburnum macrocephalum seedlings as rootstock. Cleft grafting in spring makes survival easy. Transplanting is best done after leaf drop or before budding, and the original soil should be kept. The main branches easily produce water sprouts, so proper pruning is needed after flowering to shape the tree.

Cultivation and Management of Hydrangea

The suitable growth temperature for hydrangea is 18 to 28°C, and the winter temperature should not be lower than 5°C. Flower bud differentiation requires 6 to 8 weeks at 5 to 7°C. A temperature of 20°C can promote flowering. After flowers appear, maintaining 16°C can extend the viewing period. However, high temperatures make flowers fade quickly. Hydrangea is a short-day plant. With more than 10 hours of darkness treatment per day, flower buds form in about 45 to 50 days. Potted hydrangeas commonly use 15 to 20 cm pots. After spring budding, potted plants should be watered thoroughly to ensure leaves do not wilt. During the flowering period from June to July, fertilizer and water should be sufficient, with fertilization once every half month. Normally, cultivation should avoid direct sunlight, with 60% to 70% shading being ideal. When light is too strong in midsummer, proper shading can extend the viewing period. After flowering, remove the flower stems to encourage new branches.

Loose, fertile, and well-drained sandy loam is best for the soil. However, flower color is affected by soil pH. Acidic soil produces blue flowers, and alkaline soil produces red flowers. The potting soil should be kept moist, but watering should not be excessive. Especially in the rainy season, drainage should be noted to prevent root rot caused by waterlogging. In winter, indoor potted plants are better kept slightly dry. If too moist, leaves are prone to rot. Repot once every spring. Prune properly to maintain a beautiful plant shape.

Potting and Pruning of Hydrangea

Hydrangea propagation is suitable in spring and autumn, but late spring to early summer (late April to July) is best. At this time, the flowering period of hydrangea has basically ended in May. After removing residual flowers and withered leaves and pruning, new branches and leaf buds have grown. At this time, top branch buds can be cut as cuttings. Cuttings can also be taken from late September to October. In early spring, after hydrangea is pruned and top buds are taken as cuttings, many new divided branches and leaf buds sprout again. At this time, because the weather turns cooler, it is suitable for cutting propagation.

1. In addition to seedling beds built with bricks, for easy movement and management, foam boxes can be used as seedling beds. First cut a few openings in the bottom of the box, then cover the openings with tile pieces, fill in a layer of coarse sand, and then put in cultivation soil (3 parts sand, 2 parts sterile mountain soil, mix well), level it, and then insert cuttings. Cut the cuttings into 10 to 15 cm sections, remove the lower leaves of the terminal branches, and keep only 2 to 3 leaves at the top. After cutting, tie the cuttings and smooth them. In order to make the cuttings' wounds heal and root early, soak the smoothed cuttings in strong rooting agent (about 0.2 kg of water per packet) for 5 to 10 minutes, then insert them. After inserting, press the soil around the branches firmly with your fingers so that the cuttings and soil are tightly combined. Then water thoroughly once with a watering can. After that, as long as the bed soil is moist, there is no need to water, but the leaves of the cuttings should be misted frequently and the environment around the seedling bed should be kept moist. If the climate is hot and sunlight is strong, a shade shed must be set up for shading. Under such careful management, after about 25 days the wounds begin to heal, and new roots grow from the nodes.

2. Potting and cultivation care: After about 25 days of careful management, hydrangea has survived and new leaf buds begin to grow upward from the top buds. At this time, they must be planted separately in pots for management. The cultivation soil for hydrangea uses coniferous soil (relatively high in acid) plus bran, nitrogen, phosphorus, and potassium (according to the amount of coniferous soil) compound fertilizer mixed with soil, piled and fully fermented for more than half a year. Before use, turn it over and dry it in the sun for several days before use. After the seedlings survive and the top branches grow to about 10 cm, the first pinching can be carried out to encourage new leaf buds to sprout from the lower part. When the several branch buds that grow later reach a certain length, a second pinching is carried out, and they are allowed to grow evenly and vigorously. When the main trunk branches are thick, only leave 3 to 4 branches and let them grow. From potting survival to branch setting, fertilizer should be applied 3 to 4 times, mainly potassium dihydrogen phosphate.

Pest and Disease Control of Hydrangea

1. The main pests and diseases of hydrangea are wilt disease, powdery mildew, and leaf spot disease. Spray 600 times dilution of 65% zineb wettable powder for control.

2. Pests include aphids and plant bugs. They can be killed by spraying 1500 times dilution of 40% omethoate emulsifiable concentrate.

Precautions for Hydrangea Cultivation

1. Hydrangea is toxic, and accidental ingestion of its stems and leaves can cause colic, abdominal pain, diarrhea, vomiting, rapid breathing, and bloody stools. In people's imaginations, hydrangea seems as naturally edible as marshmallows and round bread, but in fact, once hydrangea is eaten, abdominal pain appears within a few hours. Other typical poisoning symptoms include skin pain, vomiting, weakness, and sweating, and reports say patients may even experience coma, convulsions, and collapse of blood circulation in the body. Fortunately, an antidote for hydrangea poisoning has now been developed. In addition, it should be noted that hydrangea easily causes allergies, so it is generally not recommended to place it in the bedroom. Flower lovers are advised to choose flowers according to individual differences, choosing flowers they like and that are harmless. Do not plant too many flowers indoors, and pay attention to maintaining air circulation.

2. Hydrangea cultivation requires proper watering. After the Beginning of Spring, hydrangea must be exposed to rain, dew, and sunlight, and watered in the morning and evening.

The Flower Language of Hydrangea

1. Hope: Hydrangea, native to the Mediterranean, has always been famous as an evergreen tree that blooms in severe winter. In cold winter, suddenly seeing pink buds and white flowers seems to tell people that spring is near. Therefore, the flower language of hydrangea is -- hope. People born under this full flower blessing are extremely patient and tolerant. They bring hope to many people, and their own lives are also very rich.

2. Loyalty and eternity: Refers to loyalty in love and the eternity of mutual affection. The flower language of blue hydrangea is romance and contentment.

3. Contentment and reunion: The round flowers and beautiful posture of hydrangea symbolize the inseparable connection with relatives. No matter how long they are separated, they will reunite together again.