The Ultimate Guide to Growing and Caring for Chrysanthemums

Chrysanthemums, also known as mums, are iconic symbols of fall, boasting vibrant jewel-tone colors that add a pop of seasonal beauty to any garden. While it may be tempting to purchase these late-season bloomers in full bloom for instant gratification, if you aim for a hardy perennial plant that will bloom for years to come, it’s best to plant them in the spring to allow ample time for root establishment. However, you can also grow mums as annuals for their stunning fall colors and their ability to fill in empty spots left by fading summer bloomers. These versatile plants can quickly reach heights of up to 3 feet, making them a fantastic addition to any garden.

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When selecting mums, look for plants with plenty of unopened buds to ensure blooms well into the fall season. It’s important to note that chrysanthemums are toxic to pets, so if you have dogs, cats, or horses, take precautions when planting these beauties in your garden.

Chrysanthemum Care Tips

For mums to truly thrive and be hardy, they need time to establish themselves in the ground. Ideally, plant them in the spring and allow them to grow throughout the season. Mums available for purchase in the fall have often been nurtured in nurseries to set buds for September blooms, so planting them in late summer or early fall may not allow enough time for root growth.

In warmer climates, deadheading the plants after blooming may be sufficient. However, in areas with sub-zero winters, strong roots are essential to prevent the plants from being heaved out of the ground and killed by repeated freezing and thawing. Spring-planted mums have ample time for root growth and are better equipped to withstand harsh winter conditions.

Many gardeners are surprised when their mums start blooming in mid to late summer. To ensure fall blooms, pinch the plants back periodically throughout the summer, starting when they are about 4 to 5 inches tall and repeating every two to three weeks until July 4th. This practice will promote bushier growth and abundant flower buds by late summer.

Growing Conditions for Chrysanthemums

Light: Mums thrive in full sun, although they can tolerate some partial shade. Aim to plant them in an area that receives at least six hours of sunlight per day.
Soil: Chrysanthemums prefer fertile, well-drained soil with a slightly acidic pH. Work in plenty of organic matter or compost to promote healthy growth.
Water: Keep the soil consistently moist, watering the plant when the top inch feels dry. Avoid overwatering to prevent root rot.
Temperature and Humidity: Chrysanthemums are considered “hardy mums” and can withstand cool temperatures. However, high nighttime temperatures in warmer climates may delay flowering. Choose cultivars with higher heat tolerance for optimal performance.
Fertilizer: Use a 20-10-20 fertilizer when planting and during the vegetative growth phase. Once established, switch to a 5-10-5 liquid fertilizer. Avoid fertilizing after July to prevent new growth from being damaged by frost.

Varieties of Chrysanthemums

There are numerous mum varieties available, offering a range of flower colors, bloom times, and petal shapes. Some popular options include:

‘Ruby Mound’
‘Patriot’
‘Tripoli’

Propagating and Growing Chrysanthemums

You can propagate mums through division or cuttings. Division is a straightforward method best done with mature plants, while cuttings provide an exact replica of the parent plant.

Root Division: Divide plants that have been growing in the garden for at least two years to ensure they have a sufficient root system to survive.
Cuttings: Propagating from cuttings eliminates uncertainties associated with planting from seeds and allows you to replicate the parent plant more accurately.

Growing Chrysanthemums From Seed

While mums can grow from seeds, it is advisable to use purchased seeds for consistent results. Plant seeds indoors following the instructions on the seed packet, approximately six to eight weeks before the last frost date. Harden off the seedlings before transplanting them outdoors for optimal growth.

Tips for Potting and Repotting Chrysanthemums

Repotting is essential for prolonging the lifespan of your mums, especially since they are often root-bound when purchased. To repot successfully:

Choose a slightly larger container with drainage holes.
Fill the bottom of the new pot with quality potting soil.
Gently transplant the mum, ensuring the roots are surrounded by soil.
Water thoroughly until it drains from the bottom of the pot.

Overwintering Your Chrysanthemums

In colder regions, overwintering mums requires providing extra protection to the roots and crown of the plant. Leave the foliage on the plants until spring to protect them from frost damage. Heavy mulching or planting in pots and relocating to a sheltered spot can also help mums survive the winter.

Dealing with Common Pests and Diseases

While mums are relatively low-maintenance plants, they can still fall victim to pests and diseases. Keep an eye out for common issues like aphids, spider mites, and various fungal diseases such as powdery mildew and rust. Proper care and timely intervention can help keep your chrysanthemums healthy and thriving.

Encouraging Blooms and Addressing Common Problems

To ensure abundant blooms, pinch your mums throughout the spring and summer, consistently deadhead spent flowers, and provide adequate water without drowning the roots. Keep an eye out for common problems like decaying leaves, spotted leaves, and stunted growth, addressing each issue promptly to maintain the health of your plants.

It’s also crucial to consider the photoperiodic nature of chrysanthemum flowers, as they bloom in response to shorter days and longer nights. Avoid planting mums near artificial lights that may disrupt their natural cycle.

In conclusion, chrysanthemums are versatile plants that add a burst of color to fall gardens. By following these care tips and techniques, you can enjoy a vibrant display of blooms year after year. Whether you’re a seasoned gardener or a novice enthusiast, growing and caring for chrysanthemums is a rewarding experience that will bring joy to your outdoor space.