When does hydrangea usually bloom?
Hydrangea is a famous ornamental plant of the Yangtze River basin, also known as eight immortals flower, pink ball flower, grass hydrangea and so on. Its flowers are large and beautiful in color, full in shape, big and lovely, and the flower color can be red or blue, pleasing to the eye and refreshing to the mind. Hydrangea was planted in the Jiangnan gardens built during the Ming and Qing dynasties, and the parks built in the early 20th century could not do without hydrangea plantings either. Now let us take a look at when hydrangea blooms!
When does hydrangea bloom?
Hydrangea generally blooms from June to August, and the time from blooming to fading is about 25 days. The flower color of hydrangea is pink, light blue or white, but the color of hydrangea changes with the acidity and alkalinity of the soil or medium. 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.
Why does hydrangea fail to bloom?
1. Too much nitrogen fertilizer: In the early stage of flower bud differentiation, hydrangea mainly needs nitrogen fertilizer, and during the differentiation stage it mainly needs phosphorus fertilizer. However, if nitrogen and phosphorus fertilizers are applied excessively in autumn and winter, it will cause excessive nutrition in the plant, inhibit growth, make flower bud differentiation difficult, and affect blooming the following year.
2. Too weak light: When hydrangea is grown at home, limited by conditions, it receives less light, which causes leggy leaves and poor growth. The leaves consume too much nutrients, so there is insufficient nutrition during flower bud differentiation, affecting blooming.
3. Too long light exposure: Hydrangea is a short-day plant, and during the flower bud differentiation stage the light duration must not exceed 10 hours. For eight immortals flower kept indoors, long hours of lamplight at night increase light exposure and affect flower bud differentiation.
4. Improper pruning: The flowering period of hydrangea is from June to August. After the flowering period, the flowering branches should be pruned to reduce nutrient loss. If the plant grows too vigorously and is also heavily pruned in early spring, it will be difficult to form flowering branches from June to August, resulting in fewer flowers or no flowers.
How should hydrangea be grown well?
1. Soil: Hydrangea prefers loose, fertile and well-drained sandy loam, but changes in soil pH greatly change the flower color of hydrangea. 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.
2. Watering: The pot soil of hydrangea should be kept moist, but watering should not be excessive. Especially in the rainy season, attention should be paid to drainage to prevent root rot caused by waterlogging. Indoor potted plants in winter are better kept slightly dry. If too wet, the leaves are prone to rot.
3. Light: Hydrangea is a short-day plant. During normal cultivation, avoid direct sunlight, and 60-70% shade is most ideal. When the light is too strong in midsummer, proper shading can prolong the viewing period of the flowers.
4. Temperature: The suitable growth temperature for hydrangea is 18-28°C, and the winter temperature should not be lower than 5°C. Flower bud differentiation requires 6-8 weeks at 5-7°C. A temperature of 20°C can promote flowering, and maintaining 16°C after flowering can prolong the viewing period. Note that high temperatures make the flowers fade quickly.
5. Fertilizing: Hydrangea should generally be given a thin cake fertilizer water once about every 15 days. To keep the pot soil consistently acidic, 0.2% ferrous sulfate can be added when applying liquid fertilizer to make alum fertilizer water for irrigation. During the bud stage, apply 1-2 additional rounds of 0.5% superphosphate soaking liquid.
6. Pruning: After hydrangea blooms, pay attention to removing the flower stems to encourage new branches. Proper pruning can keep the plant shape beautiful. In early spring in March, cut off diseased, dead and weak branches from the base, retain 3-5 healthy main branches and shorten them, leaving 2-3 buds on each branch.
7. Pests and diseases: Hydrangea mainly suffers from wilt disease, powdery mildew and leaf spot disease, which can be prevented and controlled by spraying with 600 times dilution of 65% zineb wettable powder. Pests include aphids and mirid bugs, which can be killed by spraying with 1500 times dilution of 40% omethoate emulsifiable concentrate.
8. Repotting: Hydrangea generally needs to be repotted and have its soil changed once a year. When repotting, cut off rotted roots, decayed roots and overly long fibrous roots. After moving the plant into a new pot, firm the soil, water thoroughly, place it in a shaded place for about 10 days, and then move it outdoors for normal care.