Calendula, commonly known as Marigold, has the scientific name *Calendula officinalis*. Native to Southern Europe and Iran, it belongs to the Compositae family. This flowering plant is typically a biennial or annual herb, thriving in full sunlight, cold tolerance, and preferring cool, moist conditions. It is not overly particular about soil type and exhibits strong adaptability. The plant usually grows between 20-35 cm tall, with long oval leaves that clasp the base. Flowers appear on a single stem at the top, with flower stems measuring around 6-10 cm. The flowers are either single or multiple, often flat or double, and bloom from December to March or May. Calendula is an ideal choice for winter and spring flower beds.
Due to climatic variations in regions like Jiangsu and Zhejiang, it is mainly used during the "New Year's Day" and "Spring Festival" periods. However, its performance during "May 1st" is less satisfactory due to high temperatures. Popular varieties include "Big Stick," "Black Eye," and "Banquet," with colors predominantly yellow and orange. Notably, the "Big Stick" variety blooms approximately 10-14 days earlier than other types.
For sowing, calendula seeds contain about 130-170 grains per gram and have a star-shaped appearance. Winter and spring flowers are usually sown in September or October to ensure blooming in late winter and early spring. A large amount of seed is required, and current practices involve bed seeding and box seedling cultivation in protected environments. Some are grown in pots for commercial purposes. Soilless substrates are commonly used, with the medium disinfected, pH maintained between 6.0-6.8, and EC value between 0.5-0.75. After sowing, covering with vermiculite helps promote germination. The medium should maintain 60-70% humidity, and germination typically occurs within 8-15 days.
During the first growth stage, which begins 4-6 days after sowing, the medium should be kept slightly dry. Excessive moisture can hinder germination. The temperature should remain between 20-25°C, and light is essential—no shading is needed unless planting in September, when partial shading may be beneficial for cooling.
In the second stage, moisture is still necessary but at lower levels than the first stage. This allows roots to establish without disturbance. As the cotyledons unfold and the first true leaves fully expand, a fertilizer solution of 50 ppm 20-10-20 water-soluble flower-specific fertilizer can be applied.
The third stage marks rapid growth, requiring more water and nutrients. Alternating between 50-100 ppm 20-10-20 and 14-0-14 water-soluble fertilizers helps reduce salt buildup. Fertilization should be done regularly, ideally every time water is applied, to support healthy seedling development. Watering should alternate between wet and dry to encourage root growth. Temperatures can be reduced slightly to around 18°C. At this stage, the seedlings will have 2-3 pairs of true leaves, reach 3-4 cm in height, and have roots growing up to 3-5 cm.
The fourth stage is the refinement period. Roots are well-established, and there are typically 3 pairs of true leaves. Water should be controlled, and 14-0-14 flower-specific fertilizer is recommended. Temperatures and humidity should be slightly lower than previous stages, and proper ventilation is important to prevent disease.
After the refinement stage, seedlings can be transplanted into pots. Calendula is generally planted in 12-13 cm diameter containers and not repotted again. For spreading seedlings, using a 128 or 288-cell tray is common before moving to the final container. A small amount of compound fertilizer can be mixed into the medium as a base fertilizer.
Calendula is a high-light plant and requires full sun for optimal growth and flowering. Temperature control is crucial after transplanting, with ideal conditions around 15°C. Since it is a cold-season flower, it thrives in winter and spring, and does not require heating in greenhouses. Proper insulation is needed to prevent frost damage. If the temperature is too low, flowering may be delayed.
Water and fertilizer management should focus on the medium’s drainage and water retention. Ensuring adequate moisture while allowing the medium to dry slightly before watering promotes strong root development. Topdressing with alternating 20-10-20 and 14-0-14 fertilizers at 200-250 ppm every 7-10 days is recommended. In colder months, the use of 20-10-20 fertilizer should be limited. Calendula is sensitive to trace elements, which can lead to chlorosis and yellowing between leaves, reducing its ornamental value.
Pruning is generally not required, as it helps keep the plant neat. Outside of Jiangsu and Zhejiang, if more branching is desired, topping can be done by leaving 4-5 leaves. During winter, maintaining warmth ensures the plant remains green and produces flowers. Good ventilation is also essential.
Pest and disease management includes controlling issues like rickets, gray mold, and bacterial blight during the seedling stage. Treatments such as Plex (800-1500 times), chlorothalonil (800-1000 times), and prevention with 500-800 times solutions are effective. Common diseases later include powdery mildew, anthracnose, and bacterial blight, with treatments like powder rust (1000-1500 times), anthrax Fame (800 times), and Bordeaux mixture (1:200) for prevention. Aphids can be controlled with 40% omethoate diluted 1000 times.
The quality of the plant should be evaluated from the time the flower starts developing color until full bloom. A crown width of 15-20 cm is ideal, with a neat appearance and bright green foliage. To maintain freshness, it should not be transported for more than 12 hours. If the first flower isn't sold, it can be trimmed to remove residual blooms and still be marketable.
Aluminium Alloy Sliding Window Lock
Sliding window lock;Sliding window handle;Sliding window lock with key,with key,without key
BOGO HARDWARE & FITTING CO.,LTD , https://www.bogo-hardware.com