Chrysanthemum grandiflorum, widely recognized as the garden mum or florist’s chrysanthemum, offers a captivating display of colors and intricate blossoms. This popular flowering plant enhances gardens and floral arrangements across the globe.
Botanical Identity and Characteristics
Chrysanthemum grandiflorum is a complex hybrid species, referred to by its scientific synonyms like Chrysanthemum x morifolium or Dendranthema grandiflora. It belongs to the Asteraceae family, commonly known as the daisy family. These herbaceous perennials grow as compact, clump-forming plants, reaching heights of 2 to 4 feet and spreading up to 4 feet wide. Their leaves are deeply lobed and dark green, pinnately lobed and toothed.
The flowers vary in shape and color, appearing in shades of white, yellow, orange, pink, red, purple, bronze, and lavender. Flower forms include simple daisy-like structures with a central eye, spherical pompons, and more complex forms like quill or spider types. Most bloom from September until the first frost, with flowering influenced by day length and temperature.
Cultivation and Care
Cultivation of Chrysanthemum grandiflorum begins with proper site selection and soil preparation. These plants prefer rich, well-drained soil with organic matter, and they thrive in a slightly acidic pH. Good drainage is important to prevent waterlogging, which can lead to root rot.
Chrysanthemum grandiflorum requires ample sunlight, receiving at least five to six hours of direct sun daily for optimal growth and flowering. In hotter climates, providing some afternoon shade can protect the foliage and flowers from intense heat. Consistent watering is necessary; plants need about one inch of water per week, applied deeply at the base of the plant in the morning to allow foliage to dry and prevent fungal issues.
Fertilization supports growth and flowering. A balanced fertilizer, such as a 10-10-10 formula, can be applied every four to six weeks during the active growing season until early summer. As flower buds begin to form in summer, switching to a high-potassium fertilizer can promote better blooms. Regular pruning, or “pinching,” encourages bushier plants and more flowers; this involves removing the top few leaves of new shoots every two to three weeks until early July. Deadheading spent blooms also redirects the plant’s energy towards producing new flowers.
Pest and disease management involves regular inspection for common issues like aphids, mites, thrips, powdery mildew, and root rot. Prompt treatment with appropriate insecticides or fungicides can mitigate these problems. For overwintering in colder regions, leaving the foliage on the plants until spring and applying a thick layer of mulch around the base provides protection against freezing and thawing cycles.
Common Uses and Applications
Chrysanthemum grandiflorum is valued for its ornamental use in garden borders, containers, and as cut flowers. Their diverse forms and colors make them versatile for various landscape designs, adding vibrant displays, particularly in late summer and autumn. Many cultivars are specifically bred for the cut-flower industry, prized for their longevity in floral arrangements.
Beyond their aesthetic appeal, chrysanthemum flowers hold significance in traditional medicine, particularly in East Asian practices. Known as Ju Hua in China, chrysanthemum flowers have been used in traditional Chinese medicine for their anti-inflammatory and antioxidant properties. Extracts from the flowers are used to make fragrant teas, which are traditionally consumed to improve vision, alleviate headaches, soothe sore eyes, and reduce fever. These flowers contain active compounds such as flavonoids, saponins, and caffeic acid, which contribute to their therapeutic potential.
The plant also has culinary applications. Yellow or white chrysanthemum flowers are boiled to make a popular chrysanthemum tea in some parts of East Asia. The petals and young leaves can be parboiled and added to salads, prepared as tempura, pickled, or incorporated into soups. In Japanese cuisine, small chrysanthemums are used as a garnish for sashimi.
Culturally, the chrysanthemum holds symbolism, especially in East Asia. In China and Japan, it represents autumn, longevity, and immortality, often appearing in art, literature, and festivals. In Japan, the chrysanthemum is the official emblem of the Imperial Throne, and a specific festival is dedicated to this revered flower.
Notable Varieties and Their Features
The hybridization of Chrysanthemum grandiflorum has resulted in thousands of cultivars, each offering distinct characteristics in flower shape, color, and growth habit. These varieties are categorized by their bloom form.
One category is the pompon type, characterized by small, stiff, almost globular flowers, such as ‘Barbara’, which produces dark fuchsia pink double blooms. Another form is the irregular incurve chrysanthemum, known for its large, globular blooms with loosely incurving florets that create a full, closed center. These types, like ‘King’s Pleasure’, may require staking due to their substantial flower size.
Reflex chrysanthemums, exemplified by ‘Garnet King’, feature large, flattened globe-shaped flowers where the florets reflex or curve outwards. Varieties like ‘Chelsey Yellow’ are recognized for their uniform, mounding growth habit and sunny yellow flowers, demonstrating tolerance to less light and drier conditions. ‘Cheryl Golden’ is another compact cultivar, with golden double flowers and orange centers, making it suitable for patio containers and tolerating higher temperatures.