When do Marigolds bloom
A brief knowledge sharing with you about when marigolds bloom and an introduction to the flowering period and plant cultivation tips of marigolds, detailed introduction is as follows.
Marigolds, also known as pot marigolds, are herbaceous plants of the genus Calendula in the Asteraceae family. Marigold plants are dwarf, with dense flowers and extremely bright and eye-catching colors. They have a long flowering period and are one of the most common herbaceous flowers in early spring gardens and cities in China. Marigolds are native to Europe and have a long history of cultivation in Europe, widely used in small family gardens and potted plants, street-side planting troughs, and scattered flower beds in corners of walls. Marigolds are one of the main stars of early spring flowers, deeply loved by flower enthusiasts.
I. Morphological characteristics of marigolds
Marigolds are biennial herbaceous flowers. The entire plant is pubescent, with alternate leaves that are oblong to ovate. The flower heads are solitary, with a diameter of 4-6 cm, the edges are ligulate flowers that close at night, and the inner edges are tubular flowers. The involucres of marigolds have 1-2 rows, with linear-lanceolate bracts. The fruits are typical achenes, curved in shape, with the flowering period usually from April to June, and the fruit maturity period from May to July. Marigolds come in colors such as yellow, orange, orange-red, and white, with new cultivated varieties such as double petals, curled petals, green hearts, and deep purple hearts.
II. Requirements for cultivation conditions of marigolds
The native region of marigolds is southern Europe and the Mediterranean coast. The plants are cold-resistant, heat-averse, and prefer a sunny growing environment.
1. Temperature requirements
The suitable growth temperature for marigolds is 7-20 degrees Celsius. Seedlings can tolerate temperatures as low as minus 9 degrees Celsius in winter, while mature plants grow best at 10 degrees Celsius. If the environmental temperature is too low, it is necessary to add a plastic film for protection, otherwise the leaves may be frost-damaged. When the temperature in winter is above 10 degrees Celsius, the plant may exhibit excessive growth. In summer, when the temperature rises, the stems and leaves grow vigorously, but the flowers become smaller and the petals significantly decrease.
2. Humidity requirements
Seedlings prefer a slightly moist environment, which is beneficial for the growth of stems and leaves and can improve cold resistance in winter. Mature plants prefer slightly dry soil, which can effectively control stem and leaf growth and prevent the occurrence of stem elongation. If grown indoors or in a greenhouse, the air humidity should not be too high, as it can easily lead to diseases. We should strengthen ventilation to regulate indoor humidity.
3. Light requirements
Marigolds prefer plenty of sunlight, especially when grown indoors. Sufficient sunlight is beneficial for stem and leaf growth, resulting in sturdy and uniform seedlings. If there are too many rainy or snowy days and insufficient sunlight, the lower leaves of marigolds may turn yellow, and the roots may rot and die.
4. Soil requirements
When planting marigolds, the best soil is fertile, loose, and well-draining sandy loam or potting soil. The optimal soil pH is 6-7, with more branching and larger, more abundant flowers.
III. Tips for caring for marigolds
1. Propagation methods
Marigolds are mainly propagated by sowing, but can also be propagated by cutting. Autumn sowing or early spring indoor sowing is commonly practiced. In southern regions of China, multiple sowing periods are possible throughout the year, but autumn sowing is still preferred. Marigolds are adaptable to the environment and can overwinter outdoors. When sowing in summer, it is necessary to provide shade to prevent heat stress. In northern regions, marigolds are usually sown in spring, from April to May, with flowers blooming in early summer, able to survive the summer in cool places, and blooming again from September to October. Autumn sowing can also be done, with seedlings transplanted to a cold frame for overwintering from the end of September to early October, then moved outdoors the following spring for care, or directly potted and cultivated, moved to a low-temperature greenhouse after the frost to promote blooming in winter.
2. Seed treatment
Firstly, select high-quality seeds and remove impurities and empty seeds to ensure seed viability. Then, sun-dry the seeds to kill pathogens and enhance seed vitality, thereby effectively improving germination rates. Before formal sowing, the seeds should be soaked in warm water at 35-40 degrees Celsius for 3-4 hours, then rinsed with clean water, drained, and ready for sowing. To prevent diseases during the seedling stage, we can use chemical agents like thiophanate-methyl or carbendazim for seed dressing.
3. Sowing
Sowing should be done on a windless, sunny day. On the day of sowing, water the sowing soil thoroughly, wait for the water to渗透, and then proceed with sowing. We can use the broadcasting method, mixing the treated seeds with fine sand and spreading them in the soil in 2-3 layers, not too dense, and cover with sieved soil 1-1.5 centimeters thick.
When do marigolds bloom
4. Seedling management
The suitable germination temperature for marigolds is 20-22 degrees Celsius. Generally, seedlings emerge within 6-7 days after sowing. After the seedlings have emerged, the temperature should not exceed 30 degrees Celsius to avoid burning and rotting. When the seedlings grow to 3-5 cm and the first set of true leaves have unfolded, it is important to provide ventilation to prevent excessive growth. When the outdoor temperature stabilizes at 15 degrees Celsius, we should uncover the plastic film for seedling hardening, and stop watering about 7 days before transplanting to prepare for potting.
5. Potting
When the seedlings have 3-4 true leaves, they can be transplanted into pots for the first time. Marigolds generally use 12-15 cm diameter nursery pots, with one-time potting, eliminating the need for repotting. If seedlings are raised by broadcasting, it is best to transplant them into 128 or 288 cell trays when they have 1-2 pairs of true leaves, then pot them, which results in a higher survival rate.
6. Pest and disease control
(1) Insecticides: We usually use 80% dichlorvos emulsion at a concentration of 1000-1500 times for spray control, which has a wide range of insecticidal effects and is fast-acting. Alternatively, 40% dimethoate emulsion at a concentration of 1000-1500 times can be used for spray control, which has contact, systemic, and stomach poison effects on pests, with significant control results.
(2) Fungicides: Carbendazim is an efficient, low-toxicity, broad-spectrum systemic fungicide with protective and therapeutic effects. The main methods of use are spraying and seed dressing. Using a 50% wettable powder at a concentration of 800-1000 times for spraying can prevent various fungal diseases in marigolds. The seed dressing dosage is 0.2%-0.3% of the seed weight and can also be used as a soil disinfectant.
7. Post-management
To extend the blooming period of potted marigolds, we can place the initially blooming marigolds in a 10-degree Celsius environment with suitable lighting, which can maintain a good state for over 30 days.
Conclusion: Marigolds bloom early in spring, with strong plants, lush leaves, and bright flowers, making them an excellent spring ornamental flower variety. They are commonly used for bedding and planting in flower beds and are one of the main flower types for flower mirrors and stages. We should always remove withered flowers to ensure continuous blooming. Potted marigolds can be used for decoration and enhancement, and can also be cultivated as cut flowers, with a very wide range of applications.
The above sharing about when marigolds bloom and the detailed introduction of the flowering period of marigolds, I hope you will like it!