Chrysanthemums, often called mums, are popular flowering plants cherished for their diverse forms and vibrant colors. They bring a burst of autumn beauty to gardens and are widely used in floral arrangements. These resilient plants thrive in many climates, offering a prolonged display of color late into the growing season.
Understanding Chrysanthemum Types
Gardeners typically encounter two main categories of chrysanthemums: garden mums and florist mums. Garden mums, also known as hardy mums, are perennial varieties bred to withstand colder temperatures, making them suitable for overwintering in many regions. These types generally have a compact growth habit and produce abundant smaller flowers. Florist mums are often cultivated for their large, showy blooms and are typically treated as annuals, especially in colder climates, due to their reduced cold hardiness.
Chrysanthemums also vary significantly in their flower forms. Pompon mums feature small, globe-shaped flowers with tightly incurved ray florets, creating a dense, spherical appearance. Decorative mums display flattened, full blooms with broad, overlapping ray florets that can be incurved or reflexed. Quill mums are distinguished by their long, straight, tubular ray florets that radiate outwards, while spider mums have elongated, often hooked or coiled ray florets that resemble spider legs. These distinct forms allow gardeners to select varieties that best suit their aesthetic preferences.
Essential Chrysanthemum Care
Light Needs
Chrysanthemums require ample sunlight for abundant, healthy blooms. They perform best with at least six hours of direct sunlight daily. Full sun exposure ensures strong stems and vigorous flower development. Insufficient light can lead to leggy growth, fewer flowers, and a weaker overall plant structure.
Soil Preparation
Well-draining soil is crucial for chrysanthemum health, as they are susceptible to root rot in waterlogged conditions. A good soil mix should be rich in organic matter, such as compost or aged manure, to provide essential nutrients and improve drainage. An optimal soil pH for chrysanthemums ranges between 6.0 and 7.0, which is slightly acidic to neutral. Amending heavy clay soils with organic material can significantly enhance their structure and permeability.
Watering Techniques
Consistent moisture is important for chrysanthemums. Water the plants deeply at the base, allowing water to penetrate the root zone thoroughly. Avoid overhead watering, which can encourage fungal diseases on the foliage. The soil should remain consistently moist but never soggy, as overwatering can quickly lead to root problems.
Fertilizing Your Plants
Regular fertilization supports vigorous growth and prolific flowering. Begin feeding chrysanthemums in spring once new growth emerges, using a balanced all-purpose fertilizer. A formula with an NPK ratio like 5-10-5 or 10-10-10 promotes both foliage and bloom development. Continue fertilizing every two to four weeks throughout the growing season, reducing frequency as the plants approach their blooming period in late summer or early autumn.
Pinching and Pruning
Pinching encourages bushier growth and more flowers. When young chrysanthemum plants are about six to eight inches tall, pinch back the growing tips, removing the top one to two inches of stem. This practice encourages the plant to branch out, leading to a denser form. Continue pinching every two to four weeks until mid-July, as pinching after this time may delay or prevent flowering.
Deadheading, the removal of spent flowers, extends the blooming period. As individual flowers fade, snip them off just above the nearest healthy leaf or bud. This prevents the plant from expending energy on seed production and redirects it towards new blooms. Regular deadheading promotes a continuous display of color.
Dealing With Pests and Diseases
Chrysanthemums can encounter common garden pests, including aphids, spider mites, and leaf miners. Aphids are small, soft-bodied insects found clustered on new growth, causing distorted leaves and sticky honeydew. Spider mites, tiny arachnids, create fine webbing on leaves, leading to a stippled, discolored appearance. Leaf miners tunnel within leaves, leaving characteristic squiggly trails. For these pests, a strong spray of water can dislodge them, or insecticidal soap can be applied to affected foliage, ensuring thorough coverage of both leaf surfaces.
Fungal diseases like powdery mildew and leaf spot can affect chrysanthemums, especially in humid conditions or when air circulation is poor. Powdery mildew appears as a white, powdery coating on leaves and stems; leaf spot manifests as dark, circular lesions. To manage these issues, ensure adequate spacing between plants to promote air circulation. Remove and dispose of any severely affected leaves immediately to prevent spore spread. Proper watering techniques, avoiding overhead irrigation, also help minimize foliar diseases.
Winterizing Chrysanthemums
Preparing chrysanthemums for winter ensures survival and promotes vigorous growth the following spring. After the first hard frost causes foliage to die back, cut stems down to about four to six inches from the ground. This helps the plant conserve energy and reduces the risk of disease overwintering in decaying plant material.
Once stems are cut back, apply a thick layer of protective mulch over the plant’s crown. Materials such as straw, shredded leaves, or pine needles work well, providing insulation against freezing temperatures and preventing frost heave. A layer four to six inches deep helps regulate soil temperature, protecting the root system. For less hardy varieties or in regions with extremely cold winters, some gardeners choose to dig up their chrysanthemums, pot them, and store them in a cool, dark, frost-free location until spring.