Detailed Explanation of Key Hydrangea Planting and Management Techniques
Hydrangea, also known as ziyanghua, is an ornamental flowering shrub commonly used in parks and scenic areas, with striking red and blue flowers. This flower originated in China's Sichuan and the Japan region, and because it is relatively shade-tolerant, it can be grown even in small courtyards with poor light. Combined with its large, brilliantly colorful blooms, it has won the affection of many flower lovers and is now one of China's rare flower varieties. Today Qinnong Network brings you information on hydrangea planting and management techniques.
Growth Habits
If we want to grow a flower well, we must first understand its growth habits, so that we can create a suitable growing environment for it. Hydrangea likes warm, humid environments, with the most suitable growing temperature of 18°C to 28°C. The overwintering temperature must not be lower than 5°C. Its flowering period is from June to August. At this time, if the temperature is suitable and can be maintained at around 16°C, the flowering period will be correspondingly extended, while high temperatures will cause the flowers to fade quickly. Although hydrangea likes humid environments, it should not be watered too much on a regular basis. Especially in winter, hydrangeas kept indoors are best kept slightly dry, as excessive moisture can lead to problems such as leaf rot. The color of hydrangea is controllable: when the soil is acidic, the flowers are blue; when the soil is alkaline, the flowers are red. This characteristic is like purple litmus, but the reaction is completely opposite. Therefore, during planting, if we need the flowers to be blue, we can apply aluminum sulfate, and if we need the flowers to be red, we can apply lime to the soil.
Propagation Methods
Hydrangea can be propagated by division, layering, cutting and other methods. In a greenhouse, cuttings can be taken throughout the year. Generally, this is done in May to June, in conjunction with early spring pruning and post-bloom shaping. Select semi-lignified branches free of pests and diseases, each 10 to 15 cm long, retain 2 to 3 nodes and 1 to 2 leaves at the top, and insert them into a seedbed with river sand or vermiculite as the substrate, with appropriate shading. Keep the substrate moist and the air humidity above 80%; rooting begins in about 18 days. Afterward, gradually reduce the frequency of spraying and increase light, and transplanting can be done in about 1 month.
Planting Management
After the cutting seedlings take root, they should be potted promptly. Hydrangea likes loose, fertile soil with good drainage. It is usually prepared with leaf mold, garden soil and organic fertilizer in a 4:4:2 ratio. For large-scale production, it is advisable to prepare it with peat, perlite and organic fertilizer in a 6:2:2 ratio, and thoroughly disinfect it before use.
1. Fertilization: Hydrangea likes fertilizer, and generally an organic fertilizer is applied every half month. In the early growth stage, more nitrogen fertilizer is needed; during flower bud differentiation and bud formation, more phosphorus and potassium fertilizer is needed. You can also spray the leaves with 0.1% to 0.2% monopotassium phosphate 2 to 3 times. Stop fertilizing after the buds show color.
2. Watering: Hydrangea leaves have a very high transpiration rate, so watering must be timely. Even short-term water deficiency and wilting can cause dry leaf edges and flower necrosis. Especially in summer, shade and cooling must be used to reduce transpiration, and air humidity must be kept above 60%. In addition, hydrangea flower color is affected by soil pH, usually appearing blue in an acidic environment and red in an alkaline environment. Therefore, the pH of the water should be determined according to the desired flower color.
3. Temperature: Hydrangea cannot tolerate high temperatures and requires a temperature between 15°C and 25°C. High temperatures will make the plant dwarfed and the flower color faded, reducing quality. After the buds show color, keep the temperature at 10°C to 12°C to improve flower color and play a role in preservation.
4. Light: Hydrangea is shade-tolerant, and direct sunlight can cause sunscald, so shading is needed. Usually during the growing period, 60% shading is required. After the inflorescence shows color, appropriate shading is also needed to avoid the flower color becoming pale and losing its brilliance.
5. Pruning: Hydrangea has strong sprouting ability, and many vegetative branches will sprout from the base of the plant. To reduce nutrient consumption, they should be removed promptly. If old branches need to be replaced, robust vegetative branches can be selected as reserve branches. After flowering, cut back promptly, retaining 2 to 3 robust buds to promote new branches.
6. Flowering Regulation: To make hydrangea bloom during the Spring Festival, select robust plants 3 to 5 years old, treat them at a low temperature of 2°C to 4°C for 14 days, then move them into a greenhouse for heating, maintaining 10°C to 20°C, and they can bloom in 50 to 60 days. Pay attention to frequent ventilation, maintain good light conditions and relatively high air humidity, and apply an organic liquid fertilizer once every half month until flowering.
Pest and Disease Control
Hydrangea has few insect pests, mostly aphids, spider mites and the like, which can be controlled by spraying systemic pesticides while ensuring good ventilation. Common diseases are mostly leaf diseases, such as white rot, gray mold, leaf spot and so on. Therefore, pesticides should be sprayed regularly for prevention. Once disease is found, pesticides must be sprayed promptly, and severely diseased leaves can be removed and burned.
The above is Qinnong Network's introduction to hydrangea planting methods. Qinnong Network reminds everyone here that hydrangea is a kind of traditional Chinese medicine, but it is also toxic. If hydrangea is accidentally eaten, there will be obvious abdominal pain, accompanied by vomiting, weakness and other conditions, and even coma. Therefore, during cultivation, it must not be eaten casually. However, there is no need to be overly nervous. An antidote for hydrangea toxicity has already been developed, and it is enough to seek medical treatment immediately after accidental ingestion.